Isaac (Atlantic Ocean) 2018

Sep. 14, 2018 – NASA-NOAA Satellite Finds Winds Tearing Tropical Depression Isaac Apart

NASA-NOAA’s Suomi NPP satellite passed over tropical cyclone Isaac in the eastern Caribbean Sea and it has weakened to a depression as a result of being hammered by vertical wind shear.

Suomi NPP image of Isaac
On Sept. 14 at 1:36 a.m. EDT (0536 UTC) the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite captured an infrared image of Tropical Depression Isaac in the eastern Caribbean Sea. Coldest cloud top temperatures (red) of strongest thunderstorms were as cold as minus 70F/minus 56.6C. Credit: NOAA/NASA/NRL

Northwesterly shear continues to take a toll on Isaac. In general, wind shear is a measure of how the speed and direction of winds change with altitude. Winds at different levels of the atmosphere pushed against the cylindrical circulation center and skewed it, weakening the rotation.

On Sept. 14 at 1:36 a.m. EDT (0536 UTC) the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite captured an infrared image of Tropical Depression Isaac in the eastern Caribbean Sea. VIIRS showed wind shear was tearing the storm apart. The coldest cloud top temperatures of strongest thunderstorms were as cold as minus 70 degrees Fahrenheit/minus 56.6 degrees Celsius and were limited to one area of the storm.

The National Hurricane Center or NHC said “Although the system is still producing areas of deep convection, [satellite imagery] indicated that the circulation had become even less defined.

Moderate to strong northwesterly shear and dry mid-level air are likely to cause additional weakening, and Isaac is forecast to degenerate into an open wave within the next several days, but this could occur much sooner if the current trends continue.”

At 5 a.m. EDT (0900 UTC), the center of Tropical Depression Isaac was located near latitude 15.0 degrees north and longitude 65.5 degrees west. That’s about 190 miles (310 km) south-southwest of St. Croix. The depression is moving toward the west near 15 mph (24 kph), and this general motion with some decrease in forward speed is expected over the next few days.  Maximum sustained winds have decreased to near 35 mph (55 kph) with higher gusts. Isaac is forecast to gradually weaken over the next few days, and could degenerate into a tropical wave at any time.

On the forecast track, Isaac will move over the eastern and central Caribbean Sea during the next few days.

For updated forecasts, visit: www.nhc.noaa.gov

By Rob Gutro (with information from NHC)
NASA’s Goddard Space Flight Center

Sep. 13, 2018 – NASA-NOAA Satellite Finds Wind Shear Pushing on Tropical Storm Isaac’s Center

Wind shear seems to be affecting several storms in the Atlantic Ocean today, Sept. 13, 2018. Wind shear is affecting Hurricane Helene in the Eastern Atlantic and in the Western Atlantic, Hurricane Florence and even Tropical Storm Isaac are feeling its effects.

Suomi NPP image of Isaac
At 1:54 a.m. EDT (0554 UTC) on Sept. 13, the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite looked at Tropical Storm Isaac in infrared light. VIIRS found coldest cloud top temperatures off-center as cold as or colder than 70 degrees (red) Fahrenheit (minus 56.6 degrees Celsius). Credit: NASA/NRL

NASA-NOAA’s Suomi NPP satellite provided an infrared look at Tropical Storm Isaac that revealed its circulation center was displaced from the bulk of clouds and precipitation. That’s an indication that wind shear is affecting the storm.

What is Vertical Wind Shear?

In general, wind shear is a measure of how the speed and direction of winds change with altitude. In order to understand how it affects a tropical cyclone or hurricane, think of a tropical cyclone as a series of vertically stacked tires, all rotating. As you go up from the ground, each tire represents the rotation of the storm’s center at a higher level in the atmosphere. The different levels of rotating winds in the center of tropical cyclones need to be stacked on top each other to strengthen. If there are winds higher up that push some of the tires askew near the top, it affects the balance and rotation of the tires below. That’s what happens when vertical wind shear pushes against a storm. It pushes the center and weakens (or wobbles) the rotation of all of the tires.

The Satellite Data Reveal

The National Hurricane Center or NHC noted “Satellite imagery indicate that Isaac remains a poorly organized tropical cyclone, with the low-level center mostly exposed during the early morning hours.” Isaac is being battered by strong vertical wind shear.

At 1:54 a.m. EDT (0554 UTC) on Sept. 13, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite analyzed Tropical Storm Isaac in infrared light. VIIRS found a small area of coldest cloud top temperatures off-center were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius).

NASA research has found that cloud top temperatures as cold as or colder than the 70F/56.6C threshold have the capability to generate heavy rainfall.
At 8 a.m. EDT (1200 UTC) radiosonde data from the eastern Caribbean and NOAA Hurricane Hunter aircraft data indicate that the circulation of Isaac is fairly shallow and small. It is entirely possible that Isaac will degenerate into a tropical wave during the next day or two due to the continued effects of strong wind shear.

Warnings and Watches on Sept. 13

A Tropical Storm Warning is in effect for Martinique, Dominica and Guadeloupe. Tropical Storm Watch is in effect for Antigua, Barbuda, Montserrat, St. Kitts and Nevis, Saba and St. Eustatius, St. Martin and St. Maarten.

Isaac’s Stats on September 13, 2018

At 8 a.m. EDT (1200 UTC), the center of Tropical Storm Isaac was located near latitude 15.2 degrees north and longitude 60.9 degrees west. Isaac is moving faster toward the west near 21 mph (33 km/h). This general motion is forecast to continue today with a decrease in forward speed over the Caribbean Sea. Maximum sustained winds remain near 45 mph (75 kph) with higher gusts. Little change in strength is expected over the next several hours as Isaac moves through the Leeward Islands. Gradual weakening is forecast after that as Isaac moves through the eastern Caribbean.

Rainfall Anticipated in Leeward and Windward Islands

NHC said Tropical Storm Isaac is expected to produce total rainfall accumulations of 2 to 4 inches with isolated amounts up to 6 inches across Martinique, Dominica, and Guadeloupe, especially over elevated terrain. Rainfall of 0.5 to 1.5 inches with isolated amounts to 3 inches are forecast across Puerto Rico and the southern United States Virgin Islands, with up to an inch anticipated across the remaining Windward and Leeward Islands. This rainfall may cause dangerous flash flooding.

Isaac’s Forecast Path

NHC said on the forecast track, Isaac should move across the central Lesser Antilles and into the eastern Caribbean Sea later today, and then move across the eastern and central Caribbean Sea through the weekend.

For updated forecasts, visit: www.nhc.noaa.gov

By Rob Gutro
NASA Goddard Space Flight Center

Sep. 12, 2018 – NASA/JAXA Satellite Finds Heavy Rainfall in Tropical Storm Isaac

Tropical Cyclones generate a lot of rainfall and the Global Precipitation Measurement mission or GPM satellite and constellation of satellites gather that data and share it with forecasters. GPM recently passed over Tropical Storm Isaac and analyzed its rainfall.

GPM image of Isaac
On Sept. 11, 2018 at 11:53 p.m. EDT the GPM core observatory satellite found heaviest rainfall within Isaac was located to the southeast of the center. GPM found rain falling at a rate of over 140 mm (5.5 inches) per hour when it sliced through an isolated storm southwest of Isaac’s center. The 3D view showed heavy downpours there. Storm tops were found by GPM’s radar to reach heights above 16.2 km (10.0 km) in this area. Credit: NASA/JAXA, Hal Pierce

That rainfall is expected to affect the warning areas. The National Hurricane Center posted A Tropical Storm Warning is in effect for Martinique, Dominica and Guadeloupe. A Tropical Storm Watch is in effect for Antigua, Montserrat, St. Kitts and Nevis, and Saba and St. Eustatius.

GPM is an example of NASA’s partnerships with other agencies around the world. GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency or JAXA and the GPM core observatory satellite had an excellent view of tropical storm Isaac on Sept. 11, 2018 at 11:53 p.m. EDT (Sept. 12, 2018 at 0353 UTC).

GPM 3-D image of Isaac
On Sept. 11, 2018 at 11:53 p.m. EDT the GPM core observatory satellite found heaviest rainfall within Isaac was located to the southeast of the center. GPM found rain falling at a rate of over 140 mm (5.5 inches) per hour when it sliced through an isolated storm southwest of Isaac’s center. The 3D view showed heavy downpours there. Storm tops were found by GPM’s radar to reach heights above 16.2 km (10.0 km) in this area. Credit: NASA/JAXA, Hal Pierce

The satellite revealed that, although expected to weaken, Isaac still contained some powerful convective storms. The GPM satellite’s Microwave Imager (GMI) and Dual-Frequency Precipitation Radar (DPR) instruments collected data that were used in an analysis of Isaac’s rainfall. Those data showed that the heaviest rainfall within the tropical storm was located to the southeast of Isaac’s center of circulation. GPM’s radar (DPR Ku Band) measured rain falling at a rate of over 140 mm (5.5 inches) per hour when it sliced through an isolated convective burst southwest of Isaac’s center.

GPM’s radar (DPR ku Band) data were used in at NASA’s Goddard Space Flight Center in Greenbelt, Md. to create a 3D view from the north-northeast to show the 3D structure of precipitation within the  convective burst southwest of ISAAC’s center of circulation. DPR found that heavy downpours there. Storm tops were found by GPM’s radar to reach heights above 16.2 km (10.0 km) in this area of convection.

At 11 a.m.  (1500 UTC), the center of Tropical Storm Isaac was located by a NOAA Hurricane Hunter aircraft near latitude 15.0 degrees north and longitude 54.7 degrees west. Isaac is moving toward the west near 17 mph (28 kph), and this general motion with some decrease in forward is expected to continue through the weekend. Aircraft data indicate that maximum sustained winds remain near 60 mph (95 kph) with higher gusts. Gradual weakening is forecast during the next 72 hours.

On Sept. 11, 2018 at 11:53 p.m. EDT the GPM core observatory satellite found heaviest rainfall within Isaac was located to the southeast of the center. GPM found rain falling at a rate of over 140 mm (5.5 inches) per hour when it sliced through an isolated storm southwest of Isaac’s center. The 3D view showed heavy downpours there. Storm tops were found by GPM’s radar to reach heights above 16.2 km (10.0 km) in this area. Credit: NASA/JAXA, Hal Pierce

Hurricane Florence, tropical storm Isaac and Hurricane Helene are currently active in the Atlantic Ocean.

Tropical storm Isaac is the next tropical cyclone to affect the western Atlantic. It is moving westward toward the Leeward and Windward Islands.

The National Hurricane Center (NHC) predicts that Isaac will pass through the Leeward and Windward Islands and move into the Caribbean Sea over the next few days. The NHC predicts that Isaac will weaken as it encounters moderate vertical shear and nearby dry air.

For updated forecasts, visit: www.nhc.noaa.gov

By  Harold F. Pierce / Rob Gutro
NASA’s Goddard Space Flight Center

Sep. 11, 2018 – NASA Finds Wind Shear Pushing on Tropical Storm Isaac’s Center

NASA’s Aqua satellite provided an infrared look at Tropical Storm Isaac that revealed its circulation center was displaced from the bulk of clouds and precipitation. That’s an indication that wind shear is affecting the storm.

Aqua image of Isaac
At 1 a.m. EDT (0500 UTC) on Sept. 11, the MODIS instrument aboard NASA’s Aqua satellite looked at Tropical Storm Isaac in infrared light. MODIS found coldest cloud top temperatures off-center as cold as or colder than minus 80 degrees (yellow) Fahrenheit (minus 112 degrees Celsius). Those most powerful storms were embedded in strong storms with cloud tops as cold as or colder than minus 70 degrees (red) Fahrenheit (minus 56.6 degrees Celsius). Credit: NASA/NRL

What is Vertical Wind Shear?

In general, wind shear is a measure of how the speed and direction of winds change with altitude. In order to understand how it affects a tropical cyclone or hurricane, think of a tropical cyclone as a series of vertically stacked tires, all rotating. As you go up from the ground, each tire represents the rotation of the storm’s center at a higher level in the atmosphere. The different levels of rotating winds in the center of Tropical cyclones need to be stacked on top each other to strengthen. If there are winds higher up that push some of the tires askew near the top, it affects the balance and rotation of the tires below. That’s what happens when vertical wind shear pushes against a storm. It pushes the center and weakens (or wobbles) the rotation of all of the tires.

The Satellite Data Reveal

The National Hurricane Center or NHC noted “Satellite images indicate that the strong tropical storm still has a central dense overcast pattern and a limited amount of outer bands [of thunderstorms].  Earlier microwave data indicated that the center was not located in the middle of the convection, however, likely due to some westerly [wind] shear.”

At 2:30 a.m. EDT (0630 UTC) on Sept. 11, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite analyzed Tropical Storm Isaac in infrared light. MODIS found coldest cloud top temperatures off-center were as cold as or colder than minus 80 degrees Fahrenheit (minus 112 degrees Celsius). Those most powerful storms were embedded in strong storms with cloud tops as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius).

NASA research has found that cloud top temperatures as cold as or colder than the 70F/56.6C threshold have the capability to generate heavy rainfall.

Isaac’s Stats on September 11, 2018

At 5 a.m. EDT (0900 UTC), the center of Tropical Storm Isaac was located near latitude 14.6 degrees north and longitude 48.1 degrees west. That’s about 880 miles (1,420 km) east of the Lesser Antilles.

Isaac is moving toward the west near 14 mph (22 kph).  This general motion is expected to continue through the end of the week.  Maximum sustained winds remain near 70 mph (110 kph) with higher gusts.  Little change in strength is forecast during the next few days, but Isaac is forecast to be at or near hurricane strength as it approaches the Lesser Antilles.

Rainfall Anticipated in Leeward and Windward Islands

NHC said that Isaac is expected to produce total rainfall accumulations of 2 to 4 inches with isolated amounts near 6 inches across the Leeward Islands late this week, with 1 to 2 inches anticipated across the Windward Islands.

Isaac’s Forecast Path

On the forecast track, Isaac should move across the Lesser Antilles and into the eastern Caribbean Sea on Thursday.

For updated forecasts, visit: www.nhc.noaa.gov

By Rob Gutro
NASA’ Goddard Space Flight Center

Sep. 10, 2018 – NASA Covers Hurricane Isaac’s Ragged Center   

NASA’s Aqua satellite found a thick ring of powerful storms around Hurricane Isaac’s ragged eye and southwest of center on Sept. 10.

Aqua image of Isaac
At 12:15 a.m. EDT (0415 UTC) on Sept. 10, the MODIS instrument aboard NASA’s Aqua satellite looked at Hurricane Isaac in infrared light. MODIS found coldest cloud tops (red) had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) around the center. Credit: NASA/NRL

Infrared satellite data at 12:15 a.m. EDT (0415 UTC) on Sept. 10 from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite revealed powerful storms circling Isaac’s center and in fragmented bands southwest of the center. In those areas, MODIS found coldest cloud tops had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). NASA research has found that cloud top temperatures that cold have the capability to generate heavy rainfall.

The National Hurricane Center observed “Isaac’s cloud pattern is currently a bit ragged-looking, with an irregular central dense overcast and limited convective banding [of thunderstorms].”

At 11 a.m. EDT (1500 UTC), the National Hurricane Center or NHC noted the center of Hurricane Isaac was located near latitude 14.7 North, longitude 43.9 West. That’s about 1,150 miles (1,855 km) east of the Windward Islands. Isaac is moving toward the west near 14 mph (22 kph).  A westward motion with a slight increase in forward speed is expected through the end of the week.

Maximum sustained winds are near 75 mph (120 kph) with higher gusts.  Additional strengthening is expected over the next day or two.  Weakening is forecast to begin by the middle of the week as Isaac approaches the Lesser Antilles.

On the forecast track, Isaac should move across the Lesser Antilles and into the eastern Caribbean Sea on Thursday.

For updates on Isaac, visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Joyce (Atlantic Ocean) 2018

Sep. 18, 2018 – NASA Infrared Imagery Reveals Wind Shearing Tropical Depression Joyce

NASA’s Aqua satellite provided an infrared look at Tropical Depression Joyce and found wind shear was pushing the bulk of clouds and showers to the east of the center.

Aqua image of Joyce
At 11:20 p.m. EDT on Sept. 17 (0320 UTC on Sept. 18), the MODIS instrument aboard NASA’s Aqua satellite looked at Tropical Depression Joyce in infrared light. MODIS found a small area of coldest cloud top temperatures around the center of circulation. Those were as cold as or colder than minus 70 degrees (red) Fahrenheit (minus 56.6 degrees Celsius). Joyce is located south of the Azores Islands. Credit: NASA/NRL

The National Hurricane Center noted at 5 a.m. EDT on Sept. 18, “The latest convective burst associated with Joyce is weakening due to the effects of 35 to 40 knots of westerly vertical [wind] shear and very dry mid-level air.”

In general, wind shear is a measure of how the speed and direction of winds change with altitude. Wind shear can tear a tropical cyclone apart or weaken it.

At 11:20 p.m. EDT on Sept. 17 (0320 UTC on Sept. 18), Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite analyzed Tropical Depression Joyce in infrared light. MODIS found a small area of coldest cloud top temperatures around the center of circulation. Those were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). The bulk of the storm, however, was being pushed to the northeast from the wind shear.

NASA research has found that cloud top temperatures as cold as or colder than the 70F/56.6C threshold have the capability to generate heavy rainfall.

At 5 a.m. EDT (0900 UTC), the center of Tropical Depression Joyce was located near latitude 32.9 degrees north and longitude 27.6 degrees west. That’s 355 miles (570 km) south of the Azores Islands.

The depression is moving toward the south-southeast near 6 mph (9 kph). A turn toward the south is forecast later today, followed by a motion toward the southwest on Wednesday, Sept. 19 and Thursday, Sept. 20. Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Gradual weakening is expected during the next couple of days, and Joyce is forecast to become a remnant low later today or tonight.

For updated forecasts on Joyce, visit: www.nhc.noaa.gov

By Rob Gutro
NASA Goddard Space Flight Center

Sep. 17, 2018 – NASA Finds Tropical Depression Joyce Continues to Lose It

Visible and infrared satellite imagery from NASA’s Aqua satellite revealed Tropical Storm Joyce continues to become more disorganized.

Aqua image of Joyce
At 8:55 a.m. EDT (1205 UTC) on Sept. 17, the MODIS instrument aboard Aqua captured a visible image of Joyce. Visible satellite imagery shows a few cloud swirls pivoting around a mean center with only a small amount of strongest thunderstorms displaced about 90 miles northeast of the mean center. Credit: NASA/NRL

On Monday, Sept. 17, 2018, there were no coastal watches or warnings in effect as Joyce was far from land.

At 8:55 a.m. EDT (1205 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard Aqua captured a visible image of Joyce. Drier air is moving into the depression causing it to lose organization. The dry air is sapping the storm’s ability to form the thunderstorms that make up a tropical cyclone. Visible satellite imagery shows a few cloud swirls pivoting around a mean center with only a small amount of strongest thunderstorms displaced about 90 miles northeast of the mean center.

At 11 a.m. EDT (1500 UTC) on Sept. 17, the center of Tropical Depression Joyce was located near latitude 34.0 degrees north and longitude 28.4 degrees west. That’s 280 miles (465 km) south-southwest of the Azores Islands.

The National Hurricane Center or NHC said the depression is moving toward the east-southeast near 8 mph (13 kph) and this forward speed is expected to continue while turning toward the southeast today, south on Tuesday, and southwest on Wednesday, Sept. 19. The estimated minimum central pressure is 1008 millibars. Maximum sustained winds are near 35 mph (55 kph) with higher gusts. Some weakening is forecast during the next 48 hours.

Joyce is expected to become a remnant low tonight or Tuesday, Sept. 18.

For updated forecasts from the NHC, visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Sep. 14, 2018 – Wind Shear Affecting Tropical Storm Joyce in NASA-NOAA Satellite Image

NASA-NOAA’s Suomi NPP satellite passed over the eastern Atlantic Ocean and saw that Tropical Storm Joyce is battling wind shear. Winds are pushing thunderstorm development northeast of the center.

Suomi NPP image of Joyce
On Sept. 14 at 1:36 a.m. EDT (0536 UTC) the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite captured an infrared image of Tropical Storm Joyce. Coldest cloud top temperatures (yellow) of strongest thunderstorms were as cold as minus 50F/minus 45.5C, pushed northeast of the center. Credit: NOAA/NASA/NRL

Southwesterly shear continues to affect now Tropical Storm Joyce. In general, wind shear is a measure of how the speed and direction of winds change with altitude. Winds at different levels of the atmosphere pushed against the cylindrical circulation center and skewed it, weakening the rotation.

On Sept. 14 at 1:36 a.m. EDT (0536 UTC) the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite captured an infrared image of Tropical Storm Joyce. VIIRS showed wind shear was tearing the storm apart. The coldest cloud top temperatures of strongest thunderstorms were as cold as minus 50 degrees Fahrenheit/minus 45.5 degrees Celsius and were northeast of the center.

The National Hurricane Center or NHC said “The system continues to produce bands of convection (developing thunderstorms) over the northeastern portion of the circulation, but the center remains exposed due to shear.”

At 5 a.m. EDT (0900 UTC) the center of Tropical Storm Joyce was located near latitude 32.1 degrees north, longitude 44.9 degrees west. That’s 1,090 miles (1,750 km) west-southwest of the Azores Islands. Joyce is moving toward the south-southwest near 8 mph (13 kph).   Joyce is forecast to slow down and turn eastward by tonight, and then accelerate northeastward over the weekend.

Maximum sustained winds are near 40 mph (65 kph) with higher gusts. Little change in strength is forecast during the next couple of days.

Joyce is also close to Helene. In fact, Joyce is being steered in that direction around the larger circulation of Helene, located to its east-southeast.  Once Helene passes east-northeast of Joyce later today, Joyce should turn eastward, then begin to accelerate northeastward over the weekend of Sept. 15 and 16.

Joyce is expected to weaken early next week.

For updated forecasts, visit: www.nhc.noaa.gov

By Rob Gutro (with information from NHC)
NASA’s Goddard Space Flight Center

Sep. 13, 2018 – NASA Finds Subtropical Storm Joyce Disorganized, Wandering 

Subtropical Storm Joyce seemed dazed by its own formation, wandering in the north central Atlantic Ocean and disorganized. NASA satellite imagery confirmed the lack of organization and patchy development of thunderstorms within the system.

Terra image of Joyce
NASA’s Terra satellite captured an infrared image of Subtropical Storm Joyce at 12:40 a.m. EDT (0440 UTC) on Sept. 13. The image revealed that the low-level center is exposed to the northwest of a small patch of strong thunderstorms where cloud top temperatures were as cold as minus 63 degrees Fahrenheit (minus 53 Celsius). Credit: NASA/NRL

Joyce formed at 5 p.m. EDT on Wednesday, Sept. 12.

The Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Terra satellite captured an infrared image of Subtropical Storm Joyce at 12:40 a.m. EDT (0440 UTC) on Sept. 13. The MODIS image revealed that the low-level center is exposed to the northwest of a small patch of deep convection (strong thunderstorms that developed).

Infrared data provides temperature information. That small patch of strongest thunderstorms had cloud top temperatures as cold as minus 63 degrees Fahrenheit (minus 53 Celsius). NASA research has shown that cloud tops with temperatures that cold were high in the troposphere and have the ability to generate heavy rain.

At 11 a.m. EDT NOAA’s National Hurricane Center (NHC) noted the center of Subtropical Storm Joyce was located near latitude 33.7 degrees north and longitude 43.7 degrees west. That’s about 980 miles (1,575 km) west-southwest of the Azores Islands.

The storm is moving toward the west-southwest near 6 mph (9 kph). NHC said that a turn toward the south-southwest and then toward the south is expected later today through early Friday. A gradual turn toward the east-northeast and northeast with an increase in forward speed is expected Saturday, Sept. 15 and Sunday, Sept. 16.

Maximum sustained winds are near 40 mph (65 kph) with higher gusts. While little change in strength is forecast during the next 48 hours, Joyce could transition to a tropical storm in the next day or two.

For updated forecasts on Joyce, visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Barijat (NW Pacific Ocean) 2018

Sep. 13, 2018 – NASA-NOAA Satellite Finds Barijat Crossing Gulf of Tonkin

Tropical Cyclone Barijat appeared disorganized on satellite imagery as it moved across the Gulf of Tonkin, South China Sea. The Gulf of Tonkin is a body of water located off the coast of northern Vietnam and southern China. Barijat is being torn apart and had weakened from wind shear. After a landfall on Sept. 13, it is expected to dissipate quickly.

Suomi NPP image of Barijat
At 1:18 a.m. EDT (0518 UTC) on Sept. 13, the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite captured a visible image of Tropical Depression Barijat in the Gulf of Tonkin. Credit: NASA/NRL

In general, wind shear is a measure of how the speed and direction of winds change with altitude. Winds at different levels of the atmosphere pushed against the cylindrical circulation center and skewed it, weakening the rotation.

Barijat weakened from a tropical storm to a tropical depression today, Sept. 13.

At 1:54 a.m. EDT (0554 UTC) on Sept. 13, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite analyzed Tropical Storm Isaac showed a disorganized storm with little thunderstorm development. The Joint Typhoon Warning Center noted “Convection (rising air that form the thunderstorms that make up a tropical cyclone) has all but dissipated and remnant upper level clouds are sheared to the southwest of the low level circulation center.”

On Sept. 13 at 11 a.m. EDT (1500 UTC) Barijat’s maximum sustained winds had dropped to 28.7 mph (25 knots/46.3 kph). It was located approximately 129 nautical miles east of Hanoi, Vietnam. Barijat is moving westward and is expected to make landfall in Vietnam where it will dissipate on Sept. 14.

By Rob Gutro
NASA Goddard Space Flight Center

Sep. 12, 2o18 – NASA Sees Tropical Storm Barijat Affecting Southern China

NASA-NOAA’s Suomi NPP satellite found that as Tropical Storm Barijat was affecting Southern China, wind shear was affecting the storm.

Suomi NPP image of Barijat
Visible imagery on Sept. 12 at 1:42 a.m. EDT (0542 UTC) from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite showed that Barijat was being affected by wind shear that was pushing the bulk of its clouds southwest of center. Credit: NASA/NOAA/NRL

Visible imagery on Sept. 12 at 1:42 a.m. EDT (0542 UTC) from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite showed that Barijat was being affected by northerly vertical wind shear that was pushing the bulk of its clouds southwest of center.  In general, wind shear is a measure of how the speed and direction of winds change with altitude. Wind shear can tear a tropical cyclone apart or weaken it.

The latest Tropical Cyclone Warning Bulletin issued by the Hong Kong Observatory (HKO).at 1:45 p.m. EDT (01:45 a.m. HKT on Sept. 13) reported that the Strong Wind Signal, No. 3 is in force. That means that winds with mean speeds of 25 to 38 mph (41 to 62 kilometers) per hour are expected.

At 2 p.m. EDT on Wednesday, Sept. 12, (2 a.m. HKT local time on Sept. 13) Tropical Storm Barijat was estimated to be about 161 miles (260 kilometers) southwest of Hong Kong, near 20.8 degrees north 112.3 degrees east. Barijat is forecast to move west at about 12.4 mph (20 kph) towards the vicinity of Leizhou Peninsula. Maximum sustained winds recorded at Waglan Island were 27.3 mph (44 kph).

HKO noted that Strong Wind Signal, No. 3 will remain in force for some time. Local winds will gradually weaken later today, Sept. 13 local time.

Barijat continues to track westward and move away from Hong Kong and toward Vietnam.

For updated forecasts from HKO, visit: https://www.hko.gov.hk

By Rob Gutro
NASA’ Goddard Space Flight Center

Sep. 11, 2018 – Tropical Storm Barijat Appears Disorganized to NASA-NOAA Satellite

NASA-NOAA’s Suomi NPP satellite passed over the small Tropical Storm Barijat as it continued moving west toward southern China.

Suomi NPP image of Barijat
On Sept. 11 at 2:00 a.m. EDT (0600 UTC) the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite captured a visible image of disorganized Tropical Storm Barijat. Credit: NOAA/NASA/NRL

On Sept. 11 at 2:00 a.m. EDT (0600 UTC) the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite captured visible image of Tropical Storm Barijat. The image shows a small and disorganized system with flaring and developing thunderstorms that are obscuring the low=level circulation center.

At 11 a.m. EDT (1500 UTC), on Sept. 11 the center of Barijat was located near latitude 20.5 degrees north and longitude 116.5 degrees west. That’s about 186 nautical miles southeast of Hong Kong. Barijat was moving to the west-southwest. Maximum sustained winds are near 40 mph (35 knots/62 kph) with higher gusts.

The Joint Typhoon Warning Center forecast noted that only a slight intensification expected because of dry air near the system. After Barijat moves over southern China’s Leizhou Peninsula on Sept. 13, the storm will steadily weaken.

By Rob Gutro
NASA’ Goddard Space Flight Center

Sep. 10, 2018 – NASA Sees Tropical Storm 27W Moving Through Luzon Strait

NASA’s Aqua satellite passed over the Luzon Strait and captured a visible image of the latest tropical storm to form in the Northwestern Pacific Ocean, Tropical Storm 27W. 27W is expected to be renamed Tropical Storm Barijat.

Aqua image of Barijat
At 1:10 a.m. EDT (0510 UTC) on Sept. 10, the MODIS instrument aboard NASA’s Aqua satellite looked at Tropical Storm 27W in visible light as it was moving through the Luzon Strait. Credit: NASA/NRL

The Luzon Strait is a body of water located between Taiwan and the Philippines. It is south of Taiwan and north of Luzon, Philippines. Luzon is the largest and most populous island in the Philippines and the northernmost island.

At 1:10 a.m. EDT (0510 UTC) on Sept.10 the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite provided a visible image of Tropical Storm 27W. Satellite imagery shows a small, slowly consolidating system with flaring central convection (developing thunderstorms) and shallow bands of thunderstorms loosely wrapping into an obscured low level circulation.

At 11 a.m. EDT (1500 UTC) on Sept. 10, 27W was located near latitude 21.3 degrees north and longitude 120.4 degrees east. That’s about 225 nautical miles south of Taipei, Taiwan. Maximum sustained winds were near 40 mph (35 knots/62 kph). 27W is moving toward the west-southwest near 7 mph (6 knots/11 kph).

Tropical Storm 27W is forecast to continue tracking west-southwestward over the next three day and slowly intensify. The Joint Typhoon Warning Center noted that the storm is only expected to peak at 52 mph (45 knots/83 kph) sometime on Sept. 12. Tropical Storm 27W is expected to make landfall on Sept. 13 over the Luichow Peninsula, China and cross it where it will emerge into the Gulf of Tonkin and make a final landfall late on Sept. 13 or early Sept. 14 north of Hanoi, Vietnam.

By Rob Gutro
NASA’ Goddard Space Flight Center

Olivia (Eastern Pacific) 2018

Sep. 14, 2018 – NASA Sees Wind Shear Bringing Post-tropical Cyclone Olivia Toward Dissipation

NASA-NOAA’s Suomi NPP satellite found that as Post-tropical cyclone Olivia was being strongly affected by wind shear in the Central Pacific Ocean. That shear was preventing the development of the thunderstorms that would revive the storm, so it weakened into a post-tropical system and is expected to dissipate over the weekend of Sept. 15.

Suomi NPP image of Olivia
Infrared imagery on Sept. 13 at 7:54 p.m. EDT (2354 UTC) from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite showed that Tropical Depression Olivia was being affected by westerly wind shear that was pushing the bulk of its clouds (yellow) east of center. Credit: NASA/NOAA/NRL

Infrared imagery on Sept. 13 at 7:54 p.m. EDT (2354 UTC) from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite showed that Tropical Depression Olivia was being affected by westerly wind shear that was pushing the bulk of its clouds east of center.  In general, wind shear is a measure of how the speed and direction of winds change with altitude. Wind shear can tear a tropical cyclone apart or weaken it.

At 11 a.m. EDT (5 a.m. HST/1500 UTC) the Central Pacific Hurricane Center issued their final advisory on Olivia. At that time the center of Post-Tropical Cyclone Olivia was located near latitude 18.9 degrees north and longitude 164.2 degrees west. The

post-tropical cyclone is moving toward the west near 15 mph (24 km/h). This motion will continue into Friday, followed by a turn toward the west-northwest on Saturday.

Maximum sustained winds are near 35 mph (55 kph) with higher gusts.

Weakening is forecast, with dissipation expected by Sunday.

 By Rob Gutro
NASA’s Goddard Space Flight Center

Sep. 13, 2018 – NASA Sees Tropical Depression Olivia’s Strength Waning     

NASA’s Aqua satellite provided an infrared look at a weakening and now tropical depression Olivia in the Central Pacific Ocean. Olivia soaked the Hawaiian Islands on its east to west track through them.

Aqua image of Olivia
At 8:55 a.m. EDT (1255 UTC) on Sept. 13, the MODIS instrument aboard NASA’s Aqua satellite looked at Tropical Depression Olivia in infrared light. MODIS found a small area of powerful storms with cloud tops as cold as or colder than minus 70 degrees (red) Fahrenheit (minus 56.6 degrees Celsius) west of the Hawaiian Islands. Credit: NASA/NRL

The Central Pacific Hurricane Center or CPHC noted now that Olivia’s center has moved west of the Hawaiian Islands, as such there are no coastal watches or warnings in effect. However, interests in the northwest Hawaiian Islands should monitor the progress of Olivia.

 On Sept. 13, Olivia was moving rapidly toward the west-southwest, far southwest of Hawaii, however, flooding rainfall continues across parts of the main Hawaiian Islands.

At 2:20 a.m. EDT (0230 UTC) on Sept. 13, Moderate Resolution Imagine Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite analyzed Tropical Depression Olivia in infrared light. MODIS found coldest cloud top temperatures in powerful storms with cloud tops as cold as or colder than minus 70F (minus 56.6C) west of the Hawaiian Islands. NASA research has found that cloud top temperatures as cold as or colder than the 70F/56.6C threshold have the capability to generate heavy rainfall.

Despite the heaviest rainfall off-shore, the CPHC noted scattered thunderstorms continue to develop far northeast, southeast, and south of the low-level circulation center, but the core of the system remains completely devoid of deep convection (developing strong thunderstorms).

The CHPC forecast said “Lingering moisture from Olivia continues to cause heavy rainfall across portions of the main Hawaiian Islands this morning. These wet conditions will likely persist through tonight. Since many areas are already saturated, any additional heavy rainfall could produce life-threatening flash flooding.”

Olivia is being weakened by southwesterly vertical wind shear of over 30 knots (34.5 mph/55.5 kph). In general, wind shear is a measure of how the speed and direction of winds change with altitude. Wind shear can tear a tropical cyclone weaken it or even tear it apart.

At 11 a.m. EDT (5 a.m. HST/1500 UTC), the center of Tropical Depression Olivia was located near latitude 19.5 degrees north and longitude 162.2 degrees west. That’s about 250 miles (400 km) southwest of Lihue, Hawaii.

CPHC said the depression is moving toward the west-southwest near 18 mph (30 kph), and this general motion is expected to continue through this morning with a slight decrease in forward speed, followed by a turn toward the west later today. Olivia, or its remnant low, is forecast to turn toward the west-northwest later tonight or Friday.

Maximum sustained winds are near 35 mph (55 kph) with higher gusts. Little change in strength is forecast through tonight. Olivia is expected to become a post-tropical remnant low by Friday.

For updated forecasts on Olivia, visit: http://www.prh.noaa.gov/cphc

By Rob Gutro
NASA Goddard Space Flight Center

Sep. 12, 2018 – NASA Sees Hawaii Facing Tropical Storm Olivia

While the U.S. East Coast prepares for Hurricane Florence, the U.S. state of Hawaii is feeling the effects of Tropical Storm Olivia. NASA’s Aqua satellite provided an infrared look at Olivia that showed wind shear was affecting it before landfall.

AIRS image of Olivia
When NASA’s Aqua satellite saw Tropical Storm Olivia on Sept. 12 at 8:11 a.m. EDT (1211 UTC) was closing in on landfall in Hawaii. The AIRS instrument aboard Aqua saw coldest cloud top temperatures near minus 63F/minus 53C (purple). Credit: NASA JPL/Heidar Thrastarson

On Sept. 12, a Tropical Storm Warning is in effect for Oahu, Maui County including the islands of Maui, Molokai, Lanai, and Kahoolawe. Interests in the Northwest Hawaiian Islands should monitor the progress of Olivia.

When NASA’s Aqua satellite passed over Tropical Storm Olivia on Sept. 12 at 8:11 a.m. EDT (1211 UTC) was closing in on landfall in Hawaii. The Atmospheric Infrared Sounder or AIRS instrument analyzed the storm in infrared light which provides temperature information. Temperature is important when trying to understand how strong storms can be. The higher the cloud tops, the colder and the stronger they are.

Vertical wind shear was affecting Olivia and pushing storms east of its center. In general, wind shear is a measure of how the speed and direction of winds change with altitude. Wind shear can tear a tropical cyclone apart or weaken it.

AIRS saw coldest cloud top temperatures were as cold as minus 63 degrees Fahrenheit (minus 53 degrees Celsius) pushed east of the center. Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.

That rainfall is affecting Hawaii today, Sept. 12. The CPHC said “Showers will continue to increase over the main Hawaiian Islands today. Olivia is expected to produce total rainfall accumulations of 5 to 10 inches in some areas, with isolated maximum amounts of 15 inches possible, especially in higher terrain. This rainfall may produce life-threatening flash flooding. Up to 6 inches of rain has already fallen over parts of Maui.”

At 11 a.m. EDT (5 a.m. HST/1500 UTC), the center of Tropical Storm Olivia was located near latitude 21.2 degrees north, longitude 155.7 degrees west. That’s about 55 miles (90 km) east-northeast of Kahului Hawaii. Olivia is moving toward the west near 12 mph (19 km/h), and this motion is expected to continue through this morning. A motion toward the west-southwest is expected later today, with an increase in forward speed. This general motion is then expected to continue the next couple of days.

Maximum sustained winds are near 45 mph (75 kph) with higher gusts. Some weakening is forecast during the next 48 hours.

For updated forecasts, visit: http://www.prh.noaa.gov/cphc

By Rob Gutro
NASA’s Goddard Space Flight Center

Sep. 11, 2018 – NASA Sees Hurricane Olivia Moving Toward Hawaii

NASA’s Terra satellite provided an inside look at Hurricane Olivia as it continued to track toward Hawaii. Watches and Warnings remain in effect as Olivia nears.

Terra image of Olivia
At 4:45 a.m. EDT (0845 UTC) on Sept. 11, the MODIS instrument aboard NASA’s Terra satellite looked at Hurricane Olivia in infrared light. MODIS found coldest cloud tops (red) had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). Credit: NASA/NRL

A Tropical Storm Warning is in effect for. Oahu, Maui County…including the islands of Maui, Molokai, Lanai, and, Kahoolawe, and Hawaii County. A Tropical Storm Watch is in effect for Kauai County…including the islands of Kauai and Niihau.

At 4:45 a.m. EDT (0845 UTC) on Sept. 11, from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Terra satellite revealed strongest storms in Olivia had cloud tops with temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). NASA research has found that cloud top temperatures that cold have the capability to generate heavy rainfall.

NOAA’s Central Pacific Hurricane Center (CPHC) said “Hurricane Hunters from the 53rd Weather Reconnaissance Squadron found Olivia’s low-level center further east than anticipated. Some conflicting data exists as to the current intensity, as the central pressure has risen, but winds in the northwest quadrant were stronger than earlier today.”

At 8 a.m. EDT (2 a.m. HST/1200 UTC), the center of Tropical Storm Olivia was located near latitude 21.9 degrees north and longitude 150.7 degrees west. That’s about 320 miles (515 km) east-northeast of Hilo, Hawaii.

Maximum sustained winds are near 65 mph (100 kph) with higher gusts. Gradual weakening is forecast during the next 48 hours, but Olivia is expected to remain a tropical storm as it moves over the islands.

Olivia is moving toward the west near 10 mph (17 kph). A turn to the west-southwest is expected later today, with this general motion continuing for the next couple of days. On the forecast track, the center of Olivia will be moving over portions of the main Hawaiian Islands late tonight into Wednesday, Sept. 12.

For updated forecasts, visit: http://www.prh.noaa.gov/cphc

By Rob Gutro
NASA’ Goddard Space Flight Center

Sep. 10, 2018 – NASA Tracking Hurricane Olivia’s Track toward Hawaii

Hurricane Olivia moved from the Eastern Pacific into the Central Pacific and is expected to affect Hawaii. NASA’s Aqua satellite the northeast and southwestern quadrants of the storm to be the most powerful on Sept. 10.

Aqua image of Olivia
At 12:15 a.m. EDT (0415 UTC) on Sept. 10, the MODIS instrument aboard NASA’s Aqua satellite looked at Hurricane Olivia in infrared light. MODIS found coldest cloud tops (red) had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) around the center. Credit: NASA/NRL

Infrared satellite data at 12:15 a.m. EDT (0415 UTC) on Sept. 10 from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite revealed the strongest storms were southwest and northeast of the center. In those areas MODIS found coldest cloud tops had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). NASA research has found that cloud top temperatures that cold have the capability to generate heavy rainfall.

The MODIS data showed that the strongest storms only extended out 30 miles from the center. Hurricane-force winds extend outward up to 30 miles (45 km) from the center and tropical-storm-force winds extend outward up to 115 miles (185 km).

The Central Pacific Hurricane Center of CPHC noted a Tropical Storm Warning is in effect for Hawaii that covers Maui County, including the islands of Maui, Molokai, Lanai, and Kahoolawe and Hawaii County. A Tropical Storm Watch is in effect for Oahu.

At 11 a.m. EDT (1500 UTC/5 a.m. HST), the center of Hurricane Olivia was located near latitude 21.7 degrees north and longitude 148.0 degrees west. Maximum sustained winds are near 85 mph (140 kph) with higher gusts. Little change in strength is forecast today, with slight weakening starting tonight and continuing through Tuesday. However, Olivia is forecast to be a strong tropical storm when it reaches the Hawaiian Islands.

Olivia is moving toward the west near 10 mph (17 kph). This general motion is expected to continue early today, followed by a turn toward the west-southwest starting later today. This west-southwest motion is expected to continue through Tuesday night. On this forecast track, tropical storm conditions are expected over parts of Hawaii starting late Tuesday.

For updates on Olivia, visit: http://www.prh.noaa.gov/cphc

By Rob Gutro
NASA’s Goddard Space Flight Center

Sep. 07, 2018 – Hurricane Olivia’s Eye Obvious from NASA’s Aqua Satellite

Hurricane Olivia’s eye was clear in infrared imagery taken by NASA’s Aqua satellite from its orbit in space.

AIRS image of Olivia
At 4:50 p.m. EDT (2205 UTC) on Sept. 6, the AIRS instrument aboard NASA’s Aqua satellite looked at Hurricane Olivia in infrared light. AIRS found coldest cloud tops ( had temperatures near minus 63 degrees Fahrenheit (minus 53 degrees Celsius).Credit: NASA/NRL

Infrared satellite data at 4:50 p.m. EDT (2205 UTC) on Sept. 6, from the instrument aboard NASA’s Aqua satellite showed a clear image of Hurricane Olivia’s eye surrounded by coldest cloud top temperatures near minus 63 degrees Fahrenheit (minus 53 degrees Celsius). NASA research has found that cloud top temperatures that cold have the capability to generate heavy rainfall.

On Sept.7, Olivia’s overall cloud structure in infrared and passive microwave satellite imagery has changed little since the previous advisory, except that the cloud tops have warmed significantly around the well-defined, 20-nautical-mile in diameter eye.

At 5 a.m. EDT (0900 UTC) on Sept. 7 the National Hurricane Center or NHC noted the center of Hurricane Olivia was located near latitude 19.6 degrees north and longitude 131.2 degrees west.

Olivia is moving toward the west-northwest near 15 mph (24 kph), and this general motion is forecast to continue through Saturday.  A gradual turn toward the west is expected Saturday night or Sunday. Maximum sustained winds have decreased to near 125 mph (205 kph) with higher gusts.  Olivia is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale.

NHC said “A slow weakening trend is expected through the weekend.”

For updates on Olivia, visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Sep. 06, 2018 – NASA’s GPM Finds Heavy Rain Rings Category 3 Hurricane Olivia’s Eye

The Global Precipitation Measurement mission or GPM satellite passed over Hurricane Olivia and found heaviest rain in a tight ring around the eye.

GPM image of Olivia
On Sept. 6 at 6:31 a.m. EDT (1031 UTC) the GPM core satellite provided an analysis of rainfall rates occurring in Hurricane Olivia. Strongest rainfall was occurring around the eye at a rate of 1.5 inches (38 mm) per hour (pink). The GPM data was overlaid on infrared cloud imagery from NOAA’s GOES-West satellite. Credit: NASA/JAXA/NRL/NOAA

On Sept. 6 at 6:31 a.m. EDT (1031 UTC) the GPM core satellite provided an analysis of rainfall rates occurring in Hurricane Olivia. GPM found that heaviest rainfall rates were occurring around the eye at a rate of 1.5 inches (38 mm) per hour. Because the storm is compact, that area of heavy rainfall was also compact. Hurricane-force winds extend outward up to 25 miles (35 km) from the center and tropical-storm-force winds extend outward up to 115 miles (185 km).

At 5 a.m. EDT (0900 UTC) on Sept. 6, the National Hurricane Center or NHC noted the center of Hurricane Olivia was located near latitude 18.2 degrees north and longitude 126.5 degrees west. That’s about 1,125 miles (1,805 km) west-southwest of the southern tip of Baja California, Mexico.

Olivia is moving toward the west-northwest near 14 mph (22 kph), and this motion with some increase in forward speed is expected during the next couple of days.  A gradual turn toward the west is expected over the weekend of Sept. 8 and 9.

Maximum sustained winds have increased to near 120 mph (195 kph) with higher gusts.  Olivia is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale.  Some additional strengthening is possible today.  After that, a gradual weakening trend is forecast to begin tonight or Friday.

For updates on Olivia, visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Sep. 05, 2018 – NASA Finds a Weaker Hurricane Olivia

Infrared data from NASA’s Terra satellite revealed that the area of coldest cloud topped thunderstorms has dropped from the previous day, indicating weaker uplift and less-strong storms.

Terra image of Olivia
On Sept. 5 at 2:10 a.m. EDT (0610 UTC) the MODIS instrument aboard NASA’s Terra satellite captured an image of Hurricane Olivia. Strongest thunderstorms were smaller in area (red) than the previous day. Credit: NASA/NRL

On Sept. 5 at 2:10 a.m. EDT (0610 UTC) NASA’s Terra satellite passed over Olivia and analyzed the storm in infrared light to show temperatures. The MODIS or Moderate Resolution Imaging Spectroradiometer instrument aboard NASA’s Aqua satellite revealed cloud top temperatures as cold or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) in fragmented areas southwest and east of the center. NASA research indicates very cold cloud tops with the potential to generate very heavy rainfall.  At the time of the satellite image, Olivia had weakened but it was still a Category 3 hurricane.

Olivia encountered moderate easterly wind shear which continued to weaken the storm.

By 11 a.m. EDT (1500 UTC), the National Hurricane Center or NHC said Olivia weakened to a Category 2 hurricane on the Saffir-Simpson Hurricane Wind Scale. The center of Hurricane Olivia was located near latitude 17.1 degrees north and longitude 122.3 degrees west. Olivia was far from land areas. It was 900 miles (1,445 km) west-southwest of the southern tip of Baja California, Mexico.

Olivia is moving toward the west near 13 mph (20 kph), and this motion is expected to continue today.  A turn toward the west-northwest is expected tonight, followed by a gradual turn back toward the west over the weekend.

Maximum sustained winds have decreased to near 110 mph (175 kph) with higher gusts. The NHC said additional slow weakening is expected during the next few days.

For updated forecasts, visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Sep. 04, 2018 – Infrared NASA Data Shows Hurricane Olivia’s Strongest Sides  

NASA’s Aqua satellite passed over Hurricane Olivia and found bands of thunderstorms wrapping around its eye and improved thunderstorm development over the southern quadrant of the storm. The eastern quadrant also showed strong storms.

Aqua image of Olivia
At 5:45 a.m. EDT (0945UTC) on Sept. 4, the MODIS instrument aboard NASA’s Aqua satellite looked at Hurricane Olivia in infrared light. MODIS found coldest cloud tops (red) had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius).Credit: NASA/NRL

Infrared satellite data at 5:45 a.m. EDT (0945UTC) on Sept. 4, from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite showed coldest cloud top temperatures in Olivia in the eastern and southern quadrants. In those areas, cloud tops had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). NASA research has found that cloud top temperatures that cold have the capability to generate heavy rainfall.

Infrared data also provided forecasters with a look at surrounding sea surface temperatures (SSTs). Tropical cyclones require SSTs at least near 80 degrees Fahrenheit (26.6 degrees Celsius) to maintain strength. NHC forecasters noted at 5 a.m. EDT (0900 UTC) on Sept. 4 that “Olivia has about 24-36 hours or so remaining over warm SSTs with marginally favorable upper wind conditions.”

At 5 a.m. EDT (0900 UTC), the National Hurricane Center or NHC noted the center of Hurricane Olivia was located near latitude 16.9 degrees north and longitude 117.2 degrees west. That’s about 630 miles (1,015 km) southwest of the southern tip of Baja California, Mexico.

Olivia is moving toward the west near 12 mph (19 kph), and the hurricane is forecast to turn west-northwestward Wednesday with an increase in forward speed.

Maximum sustained winds are near 80 mph (130 kph) with higher gusts.  Some strengthening is forecast, and Olivia could become a category 2 hurricane tonight, with gradual weakening commencing early Thursday, Sept. 6.

For updates on Olivia, visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Gordon (Atlantic Ocean) 2018

Sep. 07, 2018 – Tropical Depression Gordon Still Lingering Over Arkansas

Tropical Depression Gordon just doesn’t want to give up. Gordon is meandering in the southern U.S. and satellites pinpointed its center over Arkansas on Friday, Sept. 7. Gordon continues to soak the southern U.S. and NASA’s Aqua satellite located the strongest storms associated with the depression.

AIRS image of Gordon
At 4:35 a.m. EDT (0835 UTC) on Sept. 7, the MODIS instrument aboard NASA’s Aqua satellite looked at Tropical Depression Gordon in infrared light. AIRS found coldest cloud tops had temperatures near minus 63 degrees Fahrenheit (minus 53 degrees Celsius) (in yellow) around the center over southern Arkansas. Credit: NASA/NRL

NASA’s Aqua satellite provided an infrared look at clouds associated with Gordon and found its center over Arkansas. At 4:35 a.m. EDT (0835 UTC) on Sept. 7, the MODIS or Moderate Resolution Imaging Spectroradiometer instrument aboard NASA’s Aqua satellite looked at Tropical Depression Gordon in infrared light. AIRS found coldest cloud tops had temperatures near minus 63 degrees Fahrenheit (minus 53 degrees Celsius) around the center over southern Arkansas. NASA research has shown that storms with cloud tops that cold are high in the troposphere and can produce heavy rainfall.

On Sept. 7, the National Weather Service Weather Prediction Center noted that at 5 a.m. EDT (0900 UTC), Tropical Depression Gordon was located just 30 miles (45 km) south of Little Rock, Arkansas near latitude 34.5 degrees north and longitude 92.2 degrees west. The depression was moving toward the north near 5 mph (7 kph) and this motion is expected to continue today with a turn to the northeast Saturday, Sept. 8.

Maximum sustained winds are near 10 mph (20 kph) with higher gusts. A gradual increase in winds is expected as the low becomes extra-tropical over the weekend

The estimated minimum central pressure is 1013 millibars.

As with any tropical system over land, heavy rain and flooding is a main concern. Gordon is expected to produce total rain accumulations of 3 to 6 inches over Missouri into the Midwest, with possible isolated maximum amounts of 10 inches through Saturday night. This rainfall will likely cause local flooding and flash flooding.

For more information on rainfall totals please see the Storm Summary available at www.wpc.ncep.noaa.gov/discussions/nfdscc2.html

For updates on Gordon, visit: https://www.wpc.ncep.noaa.gov/tropical/tropstorms.shtml

By Rob Gutro  
NASA’s Goddard Space Flight Center

Sep. 06, 2018 – Satellites Tracking the Rainfall from Tropical Depression Gordon

Gordon is still considered a tropical depression as it makes its way into the south central U.S. NOAA’s GOES-East satellite provided an infrared look at clouds associated with Gordon and found its center over Mississippi.

GOES image of Gordon
NOAA’s GOES-East satellite captured an infrared image of Gordon on Sept. 6 at 8 a.m. EDT (1200 UTC) as it continued to move toward Arkansas. The image showed clouds in an egg-shape near the center of circulation. Credit: NOAA/NRL

On Sept. 6, the National Weather Service noted that Flash Flood Watches are in effect over portions of Mississippi and Arkansas. The National Weather Service said that the threat of heavy rains and flooding will continue for several days.

At 5 a.m. EDT (0900 UTC), Tropical Depression Gordon was located near latitude 33.7 degrees north and longitude 91.3 degrees west. The center was located about 115 miles (185 km) north-northwest of Jackson, Mississippi.

The depression is moving toward the west-northwest near 8 mph (13 kph) and this motion is expected to continue today. Maximum sustained winds are near 25 mph (35 kph) with higher gusts. Little change in strength is forecast during the next 48 hours. The estimated minimum central pressure is 1015 millibars.

NOAA’s GOES-East satellite captured an infrared image of Gordon on Sept. 6 at 8 a.m. EDT (1200 UTC) as it continued to move toward Arkansas. The image showed clouds in an egg-shape near the center of circulation.

Gordon is expected to produce total rain accumulations of 3 to 7 inches over northwest Mississippi and much of Arkansas, up into the Midwest, with possible isolated maximum amounts of 10 inches through Saturday night. This rainfall will likely cause local flooding and flash flooding.

For more information on rainfall totals please see the Storm Summary available at www.wpc.ncep.noaa.gov/discussions/nfdscc2.html

For updates on Gordon, visit: www.nhc.noaa.gov

By Rob Gutro / Hal Pierce
NASA’s Goddard Space Flight Center

Sep. 05, 2018 – NASA Finds Strong Rain Potential in Tropical Storm Gordon

NASA’s Aqua satellite passed over the Gulf of Mexico and collected temperature information on Tropical Storm Gordon’s clouds as it moved toward landfall and after landfall. Those cloud top temperatures indicated that Gordon has the potential to generate heavy rainfall as it moves inland over the next several days.

Aqua image of Gordon
On Sept. 5 at 3:10 a.m. EDT (0710 UTC) Aqua’s MODIS instrument showed the cloud top temperatures were as cold as minus 63 degrees Fahrenheit (minus 53 degrees Celsius) in yellow. The coldest cloud tops and heavy rainmaking storms were around the low-level center and in a large band east of the center. Credit: NASA / NRL

The Atmospheric Infrared Sounder or AIRS instrument aboard NASA’s Aqua satellite passed over Tropical Storm Gordon on Sept. 4 at 3:05 p.m. EDT (19:05 UTC) and analyzed the storm in infrared light. Infrared light provides temperature data and that’s important when trying to understand how strong storms can be. The higher the cloud tops, the colder and the stronger they are.

When Aqua passed over Gordon, the AIRS instrument found coldest cloud top temperatures in thunderstorms. Those temperatures were as cold as minus 63 degrees Fahrenheit (minus 53 degrees Celsius).  Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.

Soon after the AIRS image, the National Hurricane Center or NHC noted “Gordon has been undergoing another convective bursting phase during the past few hours, with a sharp increase in Doppler velocity values noted between 9,000-12,000 feet (meaning cloud tops were reaching that altitude).”

AIRS image of Gordon
NASA’s Aqua satellite provided an infrared picture of Tropical Storm Gordon’s cloud top temperatures on Sept. 4 at 3:05 p.m. EDT (19:05 UTC). Credit: NASA JPL, Heidar Thrastarson

At 11 a.m. EDT on Sept. 4, the NHC said that aircraft and radar imagery showed that the center of Gordon was making landfall just west of the Alabama-Mississippi border.

On Sept. 5 at 3:10 a.m. EDT (0710 UTC) Aqua passed over the Gulf coast again, and the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard measured infrared temperatures. That data showed the cloud top temperatures were as cold as they were when AIRS passed over 12 hours before. However, they were not in as wide an area. The coldest cloud tops and heavy rainmaking storms were around the low-level center and in a large band east of the center.

At 8 a.m. EDT (1200 UTC) on Sept. 5, the National Hurricane Center (NHC) noted the center of Tropical Depression Gordon was located near latitude 32.0 degrees north and longitude 89.9 degrees west. The center of circulations is about 25 miles (40 km) south-southeast of Jackson, Mississippi.

Gordon is moving toward the northwest near 14 mph (22 kph).  A northwestward motion with some decrease in forward speed is expected over the next couple of days.  A turn toward the north-northwest and north is forecast to occur on Friday. Maximum sustained winds have decreased to near 35 mph (55 kph) with higher gusts in a few squalls near the center.  Additional weakening is expected as Gordon moves farther inland.

The NHC’s key messages are that heavy rainfall from Gordon will affect the western Florida Panhandle, southwest Alabama, southern and central Mississippi, northeastern Louisiana, Arkansas, Missouri, southern Iowa and Illinois, with isolated maximum amounts of 12 inches through early Saturday.  This rainfall will cause flash flooding across portions of these areas.

On the forecast track, the center of Gordon will move across the lower Mississippi Valley today.

For updated forecasts on Gordon and local effects including storm surge, rainfall, wind and tornadoes, visit: www.nhc.noaa.gov.

By Rob Gutro
NASA’s Goddard Space Flight Center

Sep. 04, 2018 – NASA Finds Tropical Storm Gordon’s Strength East of Its Center

After drenching south Florida, Tropical Storm Gordon moved into the eastern Gulf of Mexico and is headed to the northwest. NASA’s Aqua satellite found three areas of the strongest storms east of Gordon’s center when it passed overhead on Sept. 4 .

Aqua image of Gordon
At 4:05 a.m. EDT (0805 UTC) on Sept. 4, the MODIS instrument aboard NASA’s Aqua satellite looked at Tropical Storm Gordon in infrared light. MODIS found coldest cloud tops (red) had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) in three areas east of the center. Credit: NASA/NRL

Infrared satellite data on Tuesday, Sept. 4 at 4:05 a.m. EDT (0805 UTC) from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite revealed several strongest areas in Gordon where cloud top temperatures were indicative of strong storms and heavy rainmakers. In those areas, MODIS found coldest cloud tops had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). NASA research has found that cloud top temperatures that cold have the capability to generate heavy rainfall.

At 5 a.m. EDT (0900 UTC), the National Hurricane Center or NHC noted “The storm has a small CDO [central dense overcast] with convective banding features primarily over the eastern semicircle of the circulation.” It is in the eastern semicircle where Aqua found the strongest storms.

There are numerous watches and warnings in effect as Gordon is forecast to track through the Gulf of Mexico and make landfall along the northern Gulf coast. NHC said A Storm Surge Warning is in effect for Shell Beach to Dauphin Island, Alabama. A Storm Surge Watch is in effect from west of Shell Beach to the Mouth of the Mississippi River and east of Dauphin Island to Navarre, Florida. A Hurricane Warning is in effect for. The mouth of the Pearl River to the Alabama-Florida Border. A Tropical Storm Warning is in effect for west of the mouth of the Pearl River to east of Morgan City, Louisiana, including Lake Pontchartrain and Lake Maurepas and from the Alabama-Florida Border to Okaloosa-Walton County Line, Florida..

At 8 a.m. EDT (1200 UTC), the center of Tropical Storm Gordon was located near latitude 28.1 degrees north and longitude 86.2 degrees west. That’s about 190 miles (305 km) east-southeast of the mouth of the Mississippi River. Gordon is moving toward the west-northwest near 15 mph (25 kph). A west-northwestward to northwestward motion with some decrease in forward speed is expected over the next few days.

NHC said that maximum sustained winds are near 65 mph (100 kph) with higher gusts.  Some strengthening is expected today, and Gordon is forecast to be a hurricane when it makes landfall along the north-central Gulf Coast.  Rapid weakening is expected after Gordon moves inland.

On the forecast track, the center of Gordon will move across the eastern Gulf of Mexico today, and will approach the north-central Gulf Coast within the warning area late this afternoon or evening, and move inland over the lower Mississippi Valley tonight or early Wednesday, Sept. 5.

For updates on Gordon, visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Sep. 03, 2018 – NASA Observes Formation of Tropical Storm Gordon in Upper Florida Keys

Infrared data from NASA’s Aqua satellite showed Tropical Storm Gordon formed over the Upper Florida Keys on Sept. 3.

Aqua image of Gordon
At 3:20 a.m. EDT (0720 UTC) on Sept. 3, the MODIS instrument aboard NASA’s Aqua satellite looked at newly formed Tropical Storm Gordon in infrared light. MODIS found coldest cloud tops (red) had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) south of the Florida Peninsula. Fragmented bands of thunderstorms extended over south Florida. Credit: NASA/NRL

At 3:20 a.m. EDT (0720 UTC) on Sept. 3, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite looked at newly formed Tropical Storm Gordon in infrared light. MODIS found coldest cloud tops had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) south of the Florida Peninsula.  Storms with cloud top temperatures that cold have the capability to produce heavy rainfall. Fragmented bands of thunderstorms extended over south Florida and into the Bahamas.

At 5 a.m. EDT, the National Hurricane Center noted Storm Surge Watch is in effect for the Mississippi-Alabama border westward to the Mouth of the Mississippi River. A Tropical Storm Warning is in effect for Golden Beach to Bonita Beach, Florida; from Craig Key to Ocean Reef, including Florida Bay, and for the  Alabama-Florida border westward to east of Morgan City, Louisiana, including Lake Pontchartrain and Lake Maurepas. Heavy rainfall, storm surge and tropical-storm force winds are expected in the warning areas. For details: https://www.nhc.noaa.gov/text/refresh/MIATCPAT2+shtml/031227.shtml?

The National Hurricane Center noted at 8: 30 a.m. EDT (1230 UTC), the center of Tropical Storm Gordon was located by NOAA Doppler weather radar and surface observations near latitude 25.1 degrees north and longitude 80.7 degrees west.

Gordon is moving toward the west-northwest near 17 mph (28 kph) and a west-northwestward to northwestward motion is expected over the next 72 hours.  On the forecast track, the center of Gordon will pass over the southern tip of the Florida peninsula this morning, move over the southeastern Gulf of Mexico this afternoon and evening, and reach the warning area along the central Gulf Coast by late Tuesday or Tuesday night.

Surface observations and radar data indicate that maximum sustained winds have increased to near 45 mph (75 kph) with higher gusts. Additional strengthening is forecast during the next 48 hours.

For updates on Gordon, visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Jebi (was 25W – Northwestern Pacific Ocean) 2018

Sep. 06, 2018 – NASA Adds Up Heavy Rains from Typhoon Jebi

Typhoon Jebi brought flooding to Japan and NASA’s IMERG estimated rainfall over the country and the surrounding region for a one-week period.

GPM image of Jebi
Accumulated IMERG rainfall estimates over Japan and the surrounding region for the 1-week period from August 29 to Sept. 5, 2018 show rainfall amounts on the order of 100 mm (~4 inches, shown in red) or more covering much of the main island of Honshu and Shikoku in the south. Much of the band of rain oriented east-west across central Japan was due to a frontal system that brought rain to the area before Jebi made landfall.
Credit: NASA/JAXA, Hal Pierce

Super Typhoon Jebi began as an area of low pressure that formed in the vicinity of Enewetak Atoll in the far western Marshall Islands.  Two days later on the 27th of August the system was upgraded to a tropical depression, which continued to intensify, becoming a named tropical storm, the 21st of  the season, the following day.

After initially moving northwest, Jebi took a more westward track and continued to steadily intensify as it approached the Northern Mariana Islands, becoming a typhoon on the 29th, a Category 3 typhoon on the 30th, and finally a super typhoon on the 31st of August (local time) just after it passed between the islands of Pagan and Alamagan in the Northern Marianas.  Jebi then reached its peak intensity with sustained winds estimated at 175 mph by the Joint Typhoon Warning Center as it made its way into the Philippine Sea.  Over the central Philippine Sea, Jebi began to recurve toward the northwest before eventually turning northward under the influence of an upper-level trough as it neared Japan.


Accumulated IMERG rainfall estimates over Japan and the surrounding region for the 1-week period from August 29 to Sept. 5, 2018 show rainfall amounts on the order of 100 mm (~4 inches, shown in red) or more covering much of the main island of Honshu and Shikoku in the south.  Much of the band of rain oriented east-west across central Japan was due to a frontal system that brought rain to the area before Jebi made landfall.  Credit: NASA/JAXA,  Hal Pierce

As is often the case, the wind shear associated with the change in direction helped to weaken Jebi as it approached the southern part of Japan.  Nevertheless, Jebi  was the strongest typhoon to make landfall in Japan in 25 years when it came ashore over the eastern end of Shikoku, the smallest of Japan’s four main islands, Tuesday,  September 4th around noon (local time), where winds gusts of up to 129 mph were reported.  Jebi then crossed the southern coast of the main island of Honshu near Kobe, bringing heavy rains and high winds to the region.

The Integrated Multi-satellitE Retrievals for GPM (the Global Precipitation Measurement mission) or IMERG is used to estimate precipitation from a combination of passive microwave sensors, including GPM’s GMI microwave sensor and geostationary IR (infrared) data.  Accumulated IMERG rainfall estimates over Japan and the surrounding region for the 1-week period from August 29 to Sept. 5, 2018 show rainfall amounts on the order of 100 mm (~4 inches) or more covering much of the main island of Honshu and Shikoku in the south.  Much of the band of rain oriented east-west across central Japan was due to a frontal system that brought rain to the area before Jebi made landfall.

GPM is a joint satellite mission between NASA and the Japan Aerospace Exploration Agency, JAXA.

Jebi contributed much of the rainfall over Shikoku and most of the rainfall over the south central coastal regions of Honshu where it made landfall before adding to the rainfall amounts across central Honshu.

So far, the storm is being blamed for 11 fatalities and as many as 300 injuries in Japan.  The storm also caused major flooding at Kansai International Airport near Osaka where wind gusts of at least 113 mph were reported.  The storm also drove a tanker into the bridge connecting the airport to the mainland stranding many passengers.

By Steve Lang
NASA’s Goddard Space Flight Center

Sep. 04, 2018 – NASA Sees Landfall of Tropical Storm Jebi

When NASA’s Aqua satellite passed over Tropical Storm Jebi on Sept. 4 at 12:17 a.m. EDT (417 UTC) it had made landfall in southeastern Japan. The Atmospheric Infrared Sounder or AIRS instrument analyzed the storm in infrared light which provides temperature information. Temperature is important when trying to understand how strong storms can be. The higher the cloud tops, the colder and the stronger they are.

Aqua image of Jebi
NASA’s Aqua satellite passed over Jebi on Sept. 4 at 12:17 a.m. EDT (417 UTC) just after it made landfall in southeastern Japan. AIRS saw coldest cloud top temperatures (purple) being pushed east of center by strong vertical wind shear. Credit: NASA JPL/Heidar Thrastarson

AIRS saw coldest cloud top temperatures being pushed away from the center by strong vertical wind shear. Those cloud top temperatures were as cold as minus 63 degrees Fahrenheit (minus 53 degrees Celsius). Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.

At 11 a.m. EDT (1500 UTC) on Sept. 4, the Joint Typhoon Warning Center issued the final warning on Jebi. At that time the center of Jebi was located near latitude 38.9 degrees north and longitude 137.7 degrees east. The tropical storm was about 185 nautical miles west-southwest of Misawa, Japan. Jebi was moving toward the north-northeast at 45 mph (39 knots/72kph). Maximum sustained winds were near 63 mph (55 knots/102 kph) with higher gusts.

Jebi’s center crossed near Kyoto before it emerged into the Sea of Japan where it is getting caught up in the mid-latitude westerly jet stream. Jebi is in the process of becoming extra-tropical over the Sea of Japan as its wind field expands. Jebi should finish transition by Sept 5.

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 31, 2018 – NASA Finds Super Typhoon Jebi Undergoing Eyewall Replacement

The tropical cyclone known as Jebi has intensified into a super typhoon and NASA’s Terra satellite found it was undergoing eyewall replacement. Terra found powerful storms around the 15 nautical-mile wide eye in this Category 5 storm.

Aqua image of Jebi
On Aug. 31 at 8:20 a.m. EDT (1220 UTC) NASA’s Aqua satellite found the coldest temperatures of the strongest thunderstorms (yellow) in Super Typhoon Jebi were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius) around the eye and west of the center. They were embedded in a large area of storms (red) where cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). Credits: NRL/NASA

When Terra passed over Super Typhoon Jebi it appeared to be undergoing eyewall replacement. Mature, intense tropical cyclones can and often undergo an eyewall replacement cycle. That happens when a new eyewall or ring of thunderstorms within the outer rain bands forms further out from the storm’s center, outside of the original eye wall. Then, that outer ring of thunderstorms chokes off the original eye wall, starving it of moisture and momentum. Eventually, if the cycle is completed, the original eye wall of thunderstorms dissipates and the new outer eye wall of thunderstorms contracts and replace the old eye wall. The storm’s intensity can fluctuate over this period, initially weakening as the inner eye wall fades before again strengthening as the outer eye wall contracts.

On Aug. 31 at 7:15 a.m. EDT (1150 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Terra satellite found the coldest temperatures of the strongest thunderstorms around Jebi’s eye and west of the center. They were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius). Those powerful storms were embedded in a large area of storms where cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). NASA research has shown that storms with cloud top temperatures that cold (that are very high in the troposphere) have the capability to generate heavy rain.

At 11 a.m. EDT (1500 UTC) Super Typhoon Jebi’s maximum sustained winds were near 172 mph (150 knots/278 kph). Jebi’s eye was centered near 18.8 degrees north latitude and 141.0 degrees east longitude, or about 316 nautical miles northwest of Saipan. Jebi was moving to the west-northwest at 14 mph (12 knots/22 kph).

The Joint Typhoon Warning Center (JTWC) expects Jebi to start weakening but it is forecast to make landfall between Kyoto and Tokyo, Japan on Sept. 4.

For updated forecasts, visit:  http://www.prh.noaa.gov/cphc

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 30, 2018 – NASA Sees Typhoon Jebi Moving through Northwestern Pacific

NASA’s Aqua satellite passed over Typhoon Jebi in the Northwestern Pacific Ocean and saw a well-organized typhoon with a small eye.

AIRS image of Jebi
On Aug. 29 at 11:53 p.m. EDT (Aug. 30 at 0353 UTC), NASA’s Aqua satellite provided this infrared image of Typhoon Jebi in the Northwestern Pacific Ocean. Credit: NASA JPL/Heidar Thrastarson

NASA’s Aqua satellite passed over Jebi on Aug. 29 at 11:53 p.m. EDT (Aug. 30 at 0353 UTC), the Atmospheric Infrared Sounder or AIRS instrument analyzed the storm in infrared and near visible light. Enhanced infrared satellite image showed deepening convection and colder cloud tops encircling the eye.

Forecasters at the Joint Typhoon Warning Center noted “While the structure continues to improve, winds will lag slightly as the primary circulation catches up to the secondary circulation represented by convection. The environment remains favorable for continued intensification with warm sea surface temperatures, low vertical wind shear, and radial outflow.”

On Aug. 30 at 11 a.m. EDT (1500 UTC), the eye of Typhoon Jebi was located near latitude 17.8 degrees north and longitude 146.2 degrees west. That’s about 161 nautical miles north-northeast of Saipan.

Jebi was moving toward the west near 14 mph (12 knots/22kph). Maximum sustained winds have increased to near 126.6 mph (110 knots/203.7 kph) with higher gusts.  Norman is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale.  Some additional strengthening is forecast during the next 12 to 24 hours.

Jebi is expected to strengthen and maintain that strength for one and one half days, before finally starting a weakening trend on Sept. 1. Jebi is forecast to pass to the south and west of Iwo To island on the way to the big island of Japan.

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 29, 2018 – NASA’s GPM Satellite Sees Jebi as Another Tropical Threat To Japan

Japan has been afflicted by several tropical cyclones and other extreme weather this summer. GPM analyzed Typhoon Jebi as it was making its way toward Japan.

GPM image of Jebi
The GPM core observatory satellite passed above on August 28, 2018 at 2:16 p.m. EDT (1816 UTC) when Jebi was still a tropical storm. GPM found in an intense feeder band of thunderstorms south of Jebi’s center where precipitation was falling at a rate of over 87 mm (3.4 inches) per hour. This view looking toward the southwest, reveals that downpours in the feeder band south of Jebi’s center were found by the satellite to reach heights above 13.4 km (8.3 miles). Credit: NASA/JAXA, Hal Pierce

The Joint Typhoon Warning Center (JTWC) predicts that yet another typhoon called Jebi will be approaching the main islands of Japan early next week. Warm ocean temperatures and low vertical wind shear are providing a favorable environment for Jebi’s intensification. The JTWC predicts that the typhoon will have peak sustained winds of 115 knots (132 mph) as it moves over the northern Pacific Ocean toward Japan next week.

The Global Precipitation Measurement mission or GPM core observatory satellite passed above on August 28, 2018 at 2:16 p.m. EDT (1816 UTC) when Jebi was still a tropical storm. The GPM satellite’s Microwave Imager (GMI) and Dual-Frequency Precipitation Radar (DPR) instruments collected data in a swath that was centered west of tropical storm Jebi’s center of circulation. The most powerful convective storms scanned by the satellite’s radar were found in an intense feeder band of thunderstorms south of Jebi’s center of circulation. GPM’s radar (DPR Ku Band) measured precipitation falling at a rate of over 87 mm (3.4 inches) per hour in that line of storms.

The GPM core observatory satellite passed above on August 28, 2018 at 2:16 p.m. EDT (1816 UTC) when Jebi was still a tropical storm. GPM found in an intense feeder band of thunderstorms south of Jebi’s center where precipitation was falling at a rate of over 87 mm (3.4 inches) per hour. This view looking toward the southwest, reveals that downpours in the feeder band south of Jebi’s center were found by the satellite to reach heights above 13.4 km (8.3 miles). Credit: NASA/JAXA, Hal Pierce

At NASA’s Goddard Space Flight Center in Greenbelt, Md. GPM’s radar data (DPR Ku Band) was used here to show a simulated 3D view of tropical storm Jebi’s radar reflectivity values. This DPR view, looking toward the southwest, reveals that downpours in the feeder band south of Jebi’s center were returning radar reflectivity values of over 52 dBZ to the satellite. A few of these powerful storms were found by the satellite to reach heights above 13.4 km (8.3 miles).

GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.

On Aug. 29 at 11 a.m. EDT (1500 UTC), Jebi’s maximum sustained winds were near 80 mph (70 knots/129.6 kph). Jebi was centered near 17.4 degrees north latitude and 150.5 degrees east longitude. Typhoon Jebi was located approximately 330 nautical miles east-northeast of Saipan, and was moving to the west.

Jebi is forecast to move west and stay well north of Guam then curve to the west of Iwo To and head north toward Japan.

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 28, 2018 – NASA Finds a Comma-Shaped Tropical Storm Jebi in Water Vapor

When NASA’s Terra satellite analyzed water vapor within Tropical Storm Jebi in the Northwestern Pacific Ocean on Aug. 28 found the storm had taken on the classic comma-shape of an organized storm.

Terra image of Jebi
NASA’s Terra satellite passed over Tropical Storm Jebi on Aug. 28 at 7:55 a.m. EDT (1155 UTC) and highest concentrations of water vapor (brown) and coldest cloud top temperatures around the center in a large band of storms extending east and southeast of center. Credits: NASA/NRL

Because the storm has strengthened and is now threatening populated areas, a Typhoon Watch is in effect for Agrihan, Pagan and Alamagan in the in the CNMI. The CNMI is the Northern Mariana Islands, officially the Commonwealth of the Northern Mariana Islands. A Typhoon Watch means destructive winds of 74 mph or more are possible within the next 48 hours.

Tropical Depression 25W strengthened into a tropical storm on Aug. 28 and was renamed Jebi. NASA’s Terra satellite passed over Jebi on Aug. 28 at 7:55 a.m. EDT (1155 UTC) and the Moderate Resolution Imaging Spectroradiometer or MODIS instrument gathered water vapor content and temperature information.

Water vapor analysis of tropical cyclones tells forecasters how much potential a storm has to develop. Water vapor releases latent heat as it condenses into liquid. That liquid becomes clouds and thunderstorms that make up a tropical cyclone. Temperature is important when trying to understand how strong storms can be. The higher the cloud tops, the colder and the stronger they are.

MODIS saw coldest cloud top temperatures were as cold as minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) around the center of circulation and in a thick band of thunderstorms spiraling into the center from the east and southeast. Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.

The National Weather Service (NWS) in Tiyan, Guam noted at 11 a.m. EDT (1 a.m. CHST local time/1500 UTC) on Aug. 28, the center of Tropical Storm Jebi was located near latitude 16.8 degrees north and longitude 158.4 degrees East. That’s about 590 miles east of Alamagan and 600 miles east of Pagan.

Tropical Storm Jebi is moving toward the northwest at 10 mph. It is expected to make a turn toward the west with a slight increase in forward speed over the next 24 hours.

Maximum sustained winds have increased to 45 mph. Tropical Storm Jebi is forecast to intensify through Thursday, Aug. 30.

For local effects in the CNMI, visit: https://forecast.weather.gov/product.php?issuedby=PQ1&product=HLS&site=nws&format=txt

For updated forecasts from the National Weather Service in Tiyan, Guam: http://www.prh.noaa.gov/guam/cyclone.php

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 27, 2018 – NASA Looks at Water Vapor Concentration in Tropical Depression 25W

When NASA’s Terra satellite passed over the Northwestern Pacific Ocean on Aug. 27 it analyzed water vapor within newly formed Tropical Depression 25W and revealed three areas of strong concentrations.

Terra image of 25W
NASA’s Terra satellite passed over Tropical Depression 25W on Aug. 27 at 7:05 a.m. EDT (1105 UTC) and highest concentrations of water vapor (brown) and coldest cloud top temperatures in three areas of the storm. Credits: NASA/NRL

The low pressure area previously known as System 94W strengthened and consolidated enough to be re-classified as a depression. NASA’s Terra satellite passed over 25W on Aug. 27 at 7:05 a.m. EDT (1105 UTC) and the Moderate Resolution Imaging Spectroradiometer or MODIS instrument gathered water vapor content and temperature information.

Water vapor analysis of tropical cyclones tells forecasters how much potential a storm has to develop. Water vapor releases latent heat as it condenses into liquid. That liquid becomes clouds and thunderstorms that make up a tropical cyclone. Temperature is important when trying to understand how strong storms can be. The higher the cloud tops, the colder and the stronger they are.

MODIS saw coldest cloud top temperatures were as cold as minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) in three areas around the center of circulation. Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.

The National Weather Service (NWS) in Tiyan, Guam noted at 11 a.m. EDT (1 a.m. CHST local time/1500 UTC) on Aug. 27, the center of Tropical Depression 25W was located near Latitude 14.5 degrees North and Longitude 158.4 degrees East. That’s about 345 miles northwest of Enetewak, and about 525 miles north of Pohnpei.

There are no watches or warnings in effect. NWS said “Residents of the Northern Marianas Islands…including Agrihan, Pagan and Alamagan should carefully monitor the progress of Tropical Depression 25W.”

Tropical Depression 25W is moving toward the north-northwest at 10 mph. It is expected to make a turn toward the northwest with little change in forward speed during the next 24 hours.

Maximum sustained winds have increased to 35 mph. Tropical Depression 25W is forecast to intensify through Wednesday possibly becoming a tropical storm.

For updated forecasts from the National Weather Service in Tiyan, Guam: http://www.prh.noaa.gov/guam/cyclone.php

By Rob Gutro
NASA’s Goddard Space Flight Center

Norman (was 16E – Eastern Pacific) 2018

Sep. 07, 2018 – NASA Finds Hurricane Norman Hammered by Wind Shear

NASA’s Aqua satellite obtained a visible image of Hurricane Norman northeast of the Hawaiian Islands and found the storm weakening and battling wind shear.

Aqua image of Norman
At 7:50 p.m. EDT (2350 UTC) on Sept. 6, the MODIS instrument aboard NASA’s Aqua satellite looked at Hurricane Norman in visible light. Credit: NASA/NRL

NASA’s Aqua satellite provided an infrared look at Norman as it continued weakening and moving northwest of the Hawaiian Islands. It is not close enough to the islands to generate any watches or warnings, however, a large swell generated by Norman peaked across the main Hawaiian Islands overnight on Sept. 6, causing large and potentially dangerous surf along east facing shores. The surf is forecast to diminish on Friday, Sept. 7.

The Aqua satellite image taken from the MODIS instrument showed the storm was being tilted from strong vertical wind shear. The eye was covered by clouds which made the center difficult to locate.

At 5 a.m. EDT on Sept. 7 (11 p.m. HST on Sept. 6) the center of Hurricane Norman was located near latitude 22.5 North, longitude 151.7 degrees west. That’s 290 miles (470 km) northeast of Hilo, Hawaii.

Norman is moving toward the northwest near 8 mph (13 km/h) and this motion is expected to continue through Saturday, remaining east of the main Hawaiian Islands. Maximum sustained winds are near 85 mph (140 kph) with higher gusts.  Weakening is forecast through Saturday.

For updates on Norman, visit:  http://www.prh.noaa.gov/cphc

By Rob Gutro  
NASA’s Goddard Space Flight Center

Sep. 06, 2018 – Category 3 Hurricane Norman Expands its Area of Strength

The area of stronger storms in Hurricane Norman have expanded over the last several day in infrared NASA imagery as the storm intensified. Stronger thunderstorms circled Norman’s center in a thicker ring on Sept. 6 when NASA’s Terra satellite passed over the hurricane.

Terra image of Norman
At 4:25 a.m. EDT (0825 UTC) on Sept. 6, the MODIS instrument aboard NASA’s Terra satellite looked at Hurricane Norman in infrared light. MODIS found coldest cloud tops (red) had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) in a thick ring around the eye. Credit: NASA/NRL

On Sept. 6, Major Hurricane Norman was east of the Hawaiian Islands and tracking toward the west-northwest. Although there are no coastal warnings or watches in effect, NOAA’s Central Pacific Hurricane Center noted “Interests in the main Hawaiian Islands should monitor the progress of Norman over the next couple of days.”

Infrared satellite data at 4:25 a.m. EDT (0825 UTC) on Sept. 6, from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Terra satellite showed coldest cloud top temperatures in Norman completely circled the eye in a very wide band. On Sept 4, the MODIS instrument aboard NASA’s Aqua satellite showed a band of strong storms that circled the center was much thinner. As Norman intensified, the stronger storms expanded further out from the eye.

That powerful band of thunderstorms showed coldest cloud tops had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). NASA research has found that cloud top temperatures that cold have the capability to generate heavy rainfall.

At 5 a.m. EDT (0900 UTC) on Sept. 6 (11 p.m. HST on Sept. 5), the center of Hurricane Norman was located near latitude 20.3 degrees north and longitude 149.8 degrees west. Norman is moving toward the west-northwest near 8 mph. This motion is expected to continue tonight, followed by a turn toward the northwest on Thursday. Norman is forecast to continue to move toward the northwest on Friday and Saturday, and along the forecast track, the center of Norman is expected to pass 200 to 300 miles to the northeast of the main Hawaiian Islands.

Maximum sustained winds are near 120 mph (195 kph) with higher gusts.  Norman is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Weakening is expected over the next couple of days.

CPHC noted that “large swells generated by Norman will continue to build across the Hawaiian Islands through Thursday. Large and potentially dangerous surf is expected along east facing shores through at least Thursday night, Sept. 6.”

For updates on Norman, visit: http://www.prh.noaa.gov/cphc/

By Rob Gutro
NASA’s Goddard Space Flight Center

Sep. 05, 2018 – NASA-NOAA’s Suomi NPP Satellite Sees Norman Rapidly Intensifying

NASA-NOAA’s Suomi NPP analyzed Hurricane Norman in the Central Pacific Ocean as it was rapidly intensifying into a major hurricane.

Suomi NPP image of Norman
On Sept. 4 at 7:24 p.m. EDT (2324 UTC) the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite provided a visible image of Hurricane Norman in the Central Pacific Ocean. Credit: NOAA/NASA /NRL

On Sept. 4 at 7:24 p.m. EDT (2324 UTC) the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite captured a visible image of Hurricane Norman. The visible image revealed good formation with bands of thunderstorms spiraling into a cloud-filled eye. At the time, Norman was a Category 1 hurricane on the Saffir-Simpson hurricane wind scale with maximum sustained winds near 80 mph (70 knots/129.6 kph).

During the early morning on Sept. 5, maximum sustained winds rapidly intensified from 85 knots to 100 knots.

At 11 a.m.  EDT (5 a.m. HST/1500 UTC) maximum sustained winds have increased to near 115 mph (100 knots/185 kph) with higher gusts, and Norman is now a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some fluctuations in intensity are possible today, followed by gradual weakening from tonight.

The center of Hurricane Norman was located near latitude 19.5 degrees north and longitude 147.7 degrees west. That’s 480 miles (775 km) east of Hilo, Hawaii. Norman is moving toward the west near 12 mph (19 kph), and this general motion is expected to continue through this morning. Norman is expected to slow its forward motion slightly, and turn toward the west-northwest later today and tonight. A turn toward the northwest is expected Thursday and Thursday night.

Norman is expected to remain a hurricane through Thursday, Sept. 6.

For updated forecasts on Norman, visit:  http://www.prh.noaa.gov/cphc

By Rob Gutro
NASA’s Goddard Space Flight Center

Sep. 04. 2018 – Infrared NASA Imagery Shows Hurricane Norman Holding its Own

NASA’s Aqua satellite passed over Hurricane Norman in the Central Pacific Ocean and found that the storm continued to maintain its structure.

Aqua image of Norman
At 7:25 a.m. EDT (1125 UTC) on Sept. 4, the MODIS instrument aboard NASA’s Aqua satellite looked at Hurricane Norman in infrared light. MODIS found coldest cloud tops (red) had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) were around the eye and southwest of the eye. Credit: NASA/NRL

Infrared satellite data at 7:25 a.m. EDT (1125 UTC) on Sept. 4, from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite showed coldest cloud top temperatures in Norman were around the eye and southwest of the eye. In those areas, cloud tops had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). NASA research has found that cloud top temperatures that cold have the capability to generate heavy rainfall.

Overnight, Norman remained generally steady but had some recent development of new deep convection very close to the estimated low-level circulation center. A recent microwave image showed a rather well-defined eye.

At 11 a.m. EDT (5 a.m. HST/1500 UTC), the center of Hurricane Norman was located near latitude 19.9 degrees north and longitude 143.4 degrees west. That’s 760 miles (1,225 km) east of Hilo, Hawaii. Norman is moving toward the west near 17 mph (28 kph).

NOAA’s Central Pacific Hurricane Center or CPHC said a westward motion with a decrease in forward speed is expected to continue through tonight, followed by a turn to the west-northwest on Wednesday, Sept. 5 and to the northwest on Wednesday night.

Maximum sustained winds are near 85 mph (140 kph) with higher gusts. Little change in strength is forecast during the next 48 hours, with Norman forecast to remain a hurricane through Wednesday night.

CPHC noted that large ocean swells generated by Norman will produce rough surf along east facing shores of the Hawaiian Islands beginning later today and continuing through at least Thursday night.

For updates on Norman, visit: http://www.prh.noaa.gov/cphc/

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 31, 2018 – Hurricane Norman’s Southeast Quadrant Appears Strongest on NASA Imagery

NASA’s Aqua satellite provided valuable infrared temperature data on Category 4 Hurricane Norman that showed its strongest storms were southeast of center.

Aqua image of Norman
On Aug. 31 at 6:10 a.m. EDT (1010 UTC) NASA’s Aqua satellite found the coldest temperatures of the strongest thunderstorms (yellow) in Hurricane Norman were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius) southeast of the center. They were embedded in a large area of storms (red) where cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius).
Credits: NRL/NASA

On Aug. 31 at 6:10 a.m. EDT (1010 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite found the coldest temperatures of the strongest thunderstorms in Hurricane Norman were southeast of the center and were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius). They were embedded in a large area of storms   where cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). NASA research has shown that storms with cloud top temperatures that cold (that are very high in the troposphere) have the capability to generate heavy rain.

There are no coastal watches or warnings in effect as Norman is far from land. It is 825 miles (1,330 km) west-southwest of the southern tip of Baja California.

The National Hurricane Center (NHC) noted at 11 a.m. EDT (1500 UTC), the eye of Hurricane Norman was located near latitude 16.7 degrees north and longitude 120.8 degrees west. Norman is moving toward the west-southwest near 8 mph (13 kph). A turn toward the west and west-northwest with an increase in forward speed is expected over the weekend and into next week.

Maximum sustained winds have decreased to near 130 mph (215 kph) with higher gusts.  Norman is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Hurricane-force winds extend outward up to 25 miles (35 km) from the center and tropical-storm-force winds extend outward up to 90 miles (150 km).

Gradual weakening is forecast, but Norman is expected to remain a powerful hurricane through the early part of next week.

For updated forecasts on Norman, visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 30, 2018 – NASA Finds Very Cold Storm tops Circling Hurricane Norman’s Center

When NASA’s Aqua satellite passed over Hurricane Norman on Aug. 30 infrared data showed very cold storm tops around a 20 nautical-mile-wide eye.

AIRS image of Norman
On Aug. 30 at 11 a.m. EDT (1500 UTC), NOAA’s National Hurricane Center or NHC noted Norman had rapidly strengthened during the past 12 to 24 hours, with the development of a well-defined 20-nautical mile wide eye and a thick ring of cold cloud tops (purple) of minus 94 to minus 121 degrees Fahrenheit (minus 70 to minus 85 degrees Celsius) Credit: NASA JPL/Heidar Thrastarson

NASA’s Aqua satellite passed over Norman on Aug. 30 at 5:29 a.m. EDT (0929 UTC). The Atmospheric Infrared Sounder or AIRS instrument analyzed the storm in infrared light which provides temperature information. Temperature is important when trying to understand how strong storms can be. The higher the cloud tops, the colder and the stronger they are.

On Aug. 30 at 11 a.m. EDT (1500 UTC), NOAA’s National Hurricane Center or NHC noted Norman had rapidly strengthened during the past 12 to 24 hours, with the development of a well-defined 20-nautical mile wide eye and a thick ring of cold cloud tops of minus 94 to minus 121 degrees Fahrenheit (minus 70 to minus 85 degrees Celsius) Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.

The eye of Hurricane Norman was located near latitude 17.8 degrees north and longitude 118.0 degrees west. That’s about 630 miles (1,015 km) west-southwest of the southern tip of Baja California, Mexico.

Norman was moving toward the west near 8 mph (13 kph), and this motion is expected to continue today.  A west-southwestward motion is forecast on Friday, followed by a turn back toward the west and west-northwest over the weekend.

Maximum sustained winds have increased to near 150 mph (240 kph) with higher gusts.  Norman is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale.  Some additional strengthening is forecast during the next 12 to 24 hours.

Gradual weakening is anticipated to begin by Friday night or Saturday, however, Norman is expected to remain a very powerful hurricane during the next few days.

For updated forecasts, visit: www.nhc.noaa.gov.

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 29, 2018 – NASA Examines Intensifying Tropical Storm Norman

NASA’s Aqua satellite provided valuable temperature data on Tropical Storm Norman in the Eastern Pacific Ocean. Aqua data showed Norman was quickly intensifying

Aqua image of Norman
On Aug. 29 at 4:45 a.m. EDT (0845 UTC) NASA’s Aqua satellite found the coldest temperatures of the strongest thunderstorms (yellow) in Tropical Storm Norman were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius) north and south of the center. They were embedded in a large area of storms (red) where cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius).
Credits: NRL/NASA

At 11 p.m. EDT on Aug. 28, Tropical Depression 16E strengthened into a tropical storm and was renamed Norman.

On Aug. 29 at 4:45 a.m. EDT (0845 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite found the coldest temperatures of the strongest thunderstorms in Tropical Storm Norman were north and south of the center and were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius). They were embedded in a large area of storms   where cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). NASA research has shown that storms with cloud top temperatures that cold (that are very high in the troposphere) have the capability to generate heavy rain.

The National Hurricane Center (NHC) noted today, Aug. 29 that Norman is forecast to rapidly intensify and become a hurricane later today. Forecaster Berg of NHC said “Norman’s infrared satellite signature has the look of a cyclone ready to strengthen significantly over the next couple of days. Banding continues to increase, with the convective canopy expanding in nearly all quadrants.”

At 5 a.m. EDT (0900 UTC), the center of Tropical Storm Norman was located near latitude 17.5 degrees north and longitude 114.6 degrees west. That’s about 480 miles (775 km) southwest of the southern tip of Baja California, Mexico. Norman was moving toward the west near 10 mph (17 kph).  A fairly steady westward or west-southwestward motion is expected during the next several days.

Maximum sustained winds have increased to near 60 mph (95 kph) with higher gusts.  Rapid strengthening is forecast during the next 48 hours, and Norman is expected to become a hurricane later today, and possibly a major hurricane on Thursday, Aug. 30.

For updated forecasts on Norman, visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 28, 2018 – NASA Sees Formation of Eastern Pacific Tropical Depression 16E

NASA’s Aqua satellite saw the sixteenth tropical depression of the Eastern Pacific Ocean come together on Aug. 28.

Aqua image of 16E
At 5:40 a.m. EDT (0940 UTC) on Aug. 28, the MODIS instrument aboard NASA’s Aqua satellite found coldest cloud tops (red) were near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) were in fragmented storms within Tropical Depression 16E. Credit: NASA/NRL

At 5:40 a.m. EDT (0940 UTC) on Aug. 28 the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard Aqua used infrared data to measure cloud top temperatures in Tropical Depression 16E (TD16E) when it was forming.

Coldest cloud tops were near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). Aqua observed fragmented bands of thunderstorms circling a low-level center of circulation and some stronger storms within them.

Storms with cloud top temperatures that cold have the capability to produce heavy rainfall. That heavy rain was falling over open ocean waters.

On August 28, 2018 there were no coastal watches or warnings in effect because TD16E formed far from land. It was located about 420 miles (675 km) south-southwest of the southern tip of Baja California, Mexico.

At 11 a.m. EDT (1500 UTC), the center of newly formed Tropical Depression Sixteen-E was located near latitude 17.1 degrees north and longitude 111.8 degrees west. The depression is moving toward the west-northwest near 10 mph (17 kph), and this motion is expected to continue for the next day or so with a gradual turn to the west thereafter.

NOAAs National Hurricane Center said “Maximum sustained winds are near 35 mph (55 kph) with higher gusts. Some strengthening is forecast during the next 48 hours, and the depression is expected to become a tropical storm later today or on Wednesday, and a hurricane by Thursday (Aug. 30).”

For updated forecasts from the NHC, visit:  http://www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

 

Miriam (Eastern Pacific) 2018

Aug. 31, 2018 – NASA Tracking Hurricane Miriam in Central Pacific

Hurricane Miriam continues to track north through the Central Pacific Ocean and NASA’s Aqua satellite analyzed the storm infrared imagery.

Aqua image of Miriam
On Aug. 31 at 7:15 a.m. EDT (1150 UTC) NASA’s Aqua satellite found the coldest temperatures of the strongest thunderstorms (yellow) in Hurricane Miriam were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius) southwest of the center. They were embedded in a large area of storms (red) where cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). Credits: NRL/NASA

On Aug. 31 at 7:15 a.m. EDT (1150 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite found the coldest temperatures of the strongest thunderstorms Hurricane Miriam were southwest of the center and were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius). They were embedded in a large area of storms   where cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). NASA research has shown that storms with cloud top temperatures that cold (that are very high in the troposphere) have the capability to generate heavy rain.

The Central Pacific Hurricane Center (CPHC) noted at 11 a.m. EDT (5 a.m. HST/1500 UTC), the center of Hurricane Miriam was located near latitude 18.3 degrees north and longitude 141.2 degrees west. That’s about 910 miles (1,470 km) east of Hilo, Hawaii. Miriam is moving toward the north near 10 mph (17 kph). This general motion is expected to continue through tonight.

Maximum sustained winds are near 90 mph (150 kph) with higher gusts. Rapid weakening is expected to begin later today and continue through Sunday. Miriam is expected to become a post-tropical remnant low pressure area on Sunday, Sept. 2.

For updated forecasts, visit:  http://www.prh.noaa.gov/cphc

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 30, 2018 – NASA Sees Hurricane Miriam Tracking Over the Open Central Pacific

When NASA’s Aqua satellite passed over Hurricane Miriam, it was moving to the northwest and was no threat to land areas in the Central Pacific Ocean. Aqua took a look at the storm in infrared light that provided temperature data to reveal the location of the most powerful thunderstorms that make up the tropical cyclone.

AIRS image of Miriam
NASA’s Aqua satellite passed over Miriam in the Central Pacific Ocean on Aug.30 at 7:05 a.m. EDT (1105 UTC) and AIRS saw coldest cloud top temperatures (purple).Credit: NASA JPL/Heidar Thrastarson

NASA’s Aqua satellite passed over Miriam on Aug.30 at 7:05 a.m. EDT (1105 UTC) the Atmospheric Infrared Sounder or AIRS instrument analyzed the storm in infrared light which provides temperature information. Temperature is important when trying to understand how strong storms can be. The higher the cloud tops, the colder and the stronger they are.

AIRS saw coldest cloud top temperatures around the center and in a large band of thunderstorms extending east and south of the center. In both of those areas, cloud top temperatures were as cold as minus 63 degrees Fahrenheit (minus 53 degrees Celsius). Since the AIRS overpass, however, cloud tops have been warming in the southeast. There is also some drier air working its way into the circulation.

On Aug. 30 at 11 a.m. EDT (5 a.m. HST/1500 UTC) NOAA’s Central Pacific Hurricane Center or CPHC noted the center of Hurricane Miriam was located near latitude 15.3 degrees north and longitude 141.6 degrees west. That’s about 940 miles (1,510 km) east-southeast of Hilo, Hawaii.

Miriam is moving toward the northwest near 8 mph (13 kph). A turn toward the north is expected later today, with this motion continuing through Friday night. A turn toward the northwest is expected on Saturday.

Maximum sustained winds are near 80 mph (130 kph) with higher gusts. Some additional intensification is expected today, followed by fairly rapid weakening Friday through Saturday night, Sept. 1. Hurricane Miriam heading northwestward across the Central Pacific and is expected to remain far away from land.

For updated forecasts, visit: http://www.prh.noaa.gov/cphc

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 29, 2018 – NASA’s GPM Finds Heavy Rain in a Band Wrapping into Tropical Storm Miriam

NASA found heavy rainfall occurring in Tropical Storm Miriam as it continued moving through the Eastern Pacific Ocean.

GPM image of Miriam
The GPM core satellite passed over Tropical Storm Miriam on Aug. 28 at 9:39 a.m. EDT (1339 UTC) and found heavy rainfall (red) occurring in a band of thunderstorms wrapping into the low-level center from the western quadrant. Rain was falling at a rate of over 10 inches (263.3 mm/hour) in that area. Credit: NASA/JAXA, Hal Pierce

As the Global Precipitation Measurement mission or GPM core satellite passed over Tropical Storm Miriam on Aug. 28 at 9:39 a.m. EDT (1339 UTC) it continued to strengthen. GPM found heavy rainfall occurring in a band of thunderstorms wrapping into the low-level center from the western quadrant where rain was falling at a rate of over 10 inches (263.3 mm/hour). GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.

Fortunately, Miriam is far from land, so there are no coastal watches or warnings in effect.

At 5 a.m. EDT (0900 UTC) on Aug. 29, the center of Tropical Storm Miriam was located near latitude 14.2 degrees north and longitude 138.4 degrees west. That’s about 1,165 miles (1,875 km) east-southeast of Hilo, Hawaii.  Miriam was moving toward the west near 13 mph (20 kph).  A turn toward the west-northwest with a decrease in forward speed is expected by tonight, followed by a turn toward the northwest and north through Friday night.

Maximum sustained winds are near 65 mph (100 kph) with higher gusts. Tropical-storm-force winds extend outward up to 80 miles (130 km) from the center. The estimated minimum central pressure is 999 millibars.

Some strengthening is possible during the next day or two, but Miriam is expected to begin weakening by Friday.

For updated forecasts on Miriam, visit: www.nhc.noaa.gov

By  Rob Gutro / Hal Pierce
NASA’s Goddard Space Flight Center

Aug. 28, 2018 – NASA Finds Little Improvement in Miriam’s Structure

When NASA’s Aqua satellite passed over Tropical Storm Miriam Aug. 27 and infrared data showed slight improvement from the day before. On Aug. 28, wind shear was still affecting the storm.

AIRS image of Miriam
NASA’s Aqua satellite passed over Tropical Storm Miriam on Aug. 27 at 6:35 a.m. EDT (1035 UTC). AIRS saw coldest cloud top temperatures (purple) around its center of circulation. Credit: NASA JPL/Heidar Thrastarson

NASA’s Aqua satellite passed Tropical Storm Miriam on Aug. 27 at 6:35 a.m. EDT (1035 UTC). The Atmospheric Infrared Sounder or AIRS instrument analyzed the storm in infrared light which provides temperature information. Temperature is important when trying to understand how strong storms can be. The higher the cloud tops, the colder and the stronger they are.

AIRS saw coldest cloud top temperatures being pushed slightly east of center by light vertical wind shear. Those cloud top temperatures were as cold as minus 63 degrees Fahrenheit (minus 53 degrees Celsius). Storms with cloud top temperatures that cold have the capability to produce heavy rainfall. At the time of the Aqua satellite overpass, Miriam’s cloud pattern and overall convective organization had improved from earlier in the day.

On Tuesday, August 28, 2018, the National Hurricane Center (NHC) noted that Miriam’s cloud pattern had still not improved very much from Aug. 27. On Aug. 29, microwave data showed the low-level center still slightly displaced from the deep convection due to about 11.5 mph (10 knots/18.5 kph) of northwesterly wind shear.

At 5 a.m. EDT (2 a.m. PDT/0900 UTC), the center of Tropical Storm Miriam was located near latitude 14.0 degrees north and longitude 133.5 degrees west. That’s about 1,480 miles (2,380 km) east-southeast of Hilo, Hawaii. Miriam was moving toward the west near 12 mph (19 kph), and the NHC said this motion is expected to continue through Wednesday. A turn toward the northwest and north-northwest is expected Thursday, Aug. 30 and Friday, Aug. 31.

Maximum sustained winds remain near 65 mph (100 kph) with higher gusts.  Some strengthening is forecast during the next 48 hours, and Miriam is expected to become a hurricane later today or tonight.

For updated forecasts, visit the National Hurricane Center website:   www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 27, 2018 – NASA Observes Tropical Storm Miriam’s Formation

Tropical cyclones continue to regularly develop in the Eastern Pacific Ocean. As Tropical Storm Miriam was developing, the GPM or Global Precipitation Measurement mission or GPM core satellite observed the rainfall happening within the storm.

GPM image of Miriam
On Aug. 26 at 0223 UTC (Aug. 25 at 10:23 p.m. EDT) the GPM core observatory satellite revealed that extremely heavy rainfall was occurring within the organizing storm. GPM’s radar measured rain falling at over 190 mm (7.5 inches) per hour in one powerful storm. The most powerful storm in this simulated 3D view from the north-northeast was shown by GPM’s radar to reach heights of about 15 km (9.3 miles). Credit: NASA/JAXA, Hal Pierce

Tropical Depression Fifteen-E (TD15E) formed in the eastern Pacific Ocean about 1,000 nautical miles (1852 km) southwest of the Baja California peninsula early on Sunday Aug. 26, 2018.  TD15E became better organized with increased banding later in the day and was upgraded by the National Hurricane Center (NHC) to tropical storm Miriam.

At 11 a.m. EDT (1500 UTC) on Aug. 27 the center of Tropical Storm Miriam was located near latitude 13.9 degrees north and longitude 130.5 degrees west. That’s about 1,485 miles (2,385 km) west-southwest of the southern tip of Baja California, Mexico.

On Aug. 26 at 0223 UTC (Aug. 25 at 10:23 p.m. EDT) the GPM core observatory satellite revealed that extremely heavy rainfall was occurring within the organizing storm. GPM’s radar measured rain falling at over 190 mm (7.5 inches) per hour in one powerful storm. The most powerful storm in this simulated 3D view from the north-northeast was shown by GPM’s radar to reach heights of about 15 km (9.3 miles). Credit: NASA/JAXA, Hal Pierce

Miriam is moving toward the west near 14 mph (22 kph), and this general motion is expected to continue for the next couple of days. A turn toward the west-northwest is expected on Thursday.  On the forecast track, Miriam will approach the central Pacific basin late Wednesday or Wednesday night.

Maximum sustained winds have increased to near 65 mph (100 kph) with higher gusts.  Additional strengthening is forecast during the next 2 to 3 days, and Miriam is expected to become a hurricane tonight or early Tuesday, Aug. 28.

The National Hurricane Center (NHC) predicts that Miriam will intensify as it moves toward the west along the southern periphery of the strong ridge to its north.  Miriam is expected to become a hurricane tomorrow.  The hurricane is expected to make a turn to the north in a few days as it moves into the central Pacific Ocean. Miriam is then forecast to weaken back to tropical storm intensity on September 1, 2018.

For updated forecasts on Miriam, visit: www.nhc.noaa.gov

By Harold F. Pierce / Rob Gutro
NASA Goddard Space Flight Center

Lane (Eastern Pacific Ocean) 2018

Aug. 29 – NASA Sees Post-Tropical Cyclone Lane Come to an End

The once hurricane that dropped record-setting rainfall on the Hawaiian Islands has come to an end in the Central Pacific Ocean and NASA-NOAA’s Suomi NPP satellite captured a visible image of its final hours.

Suomi NPP image of Lane
NASA-NOAA’s Suomi NPP satellite flew over Post-Tropical Cyclone Lane on Aug. 28 at 7:54 p.m. EDT (2354 UTC). The image showed the storm devoid of clouds except in the northeastern quadrant. Credit: NASA/NOAA/NRL

NASA-NOAA’s Suomi NPP satellite flew over Post-Tropical Cyclone Lane on Aug. 28 at 7:54 p.m. EDT (2354 UTC).The  Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite provided a visible image that showed wind shear has taken its toll on the storm and pushed all of the clouds northeast of the cloud-less center of circulation.

The final warning came from NOAA’s Central Pacific Hurricane Center at 0300 UTC on Aug. 29 (11 p.m. EDT on Aug. 28) when Lane’s center was located near 19.5 degrees north latitude and 168.3 degrees west longitude. That’s 330 miles south-southwest of French Frigate Shoals, Hawaii. At the time, maximum sustained winds were near 28.7 mph (25 knots/46.3 kph).

Lane has ceased to be a tropical cyclone and will dissipate soon.

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 28 – NASA Looks at Fluctuating Strength of Tropical Storm Lane

When NASA’s Aqua satellite passed over tropical cyclone Lane on Aug. 27 it had just regained tropical storm status and showed powerful thunderstorms around east of its center of circulation. However, wind shear kicked back up and by 11 p.m. EDT that day, Lane had again weakened back to tropical depression status.

AIRS image of Lane
NASA’s Aqua satellite passed over Lane on Aug. 27 at 8:17 a.m. EDT (1217 UTC) just after it regained tropical storm status. AIRS saw coldest cloud top temperatures (purple) being pushed east of center by strong vertical wind shear. Credit: NASA JPL/Heidar Thrastarson

NASA’s Aqua satellite passed over Lane on Aug. 27 at 8:17 a.m. EDT (1217 UTC). The Atmospheric Infrared Sounder or AIRS instrument analyzed the storm in infrared light which provides temperature information. Temperature is important when trying to understand how strong storms can be. The higher the cloud tops, the colder and the stronger they are.

AIRS saw coldest cloud top temperatures being pushed east of center by strong vertical wind shear. Those cloud top temperatures were as cold as minus 63 degrees Fahrenheit (minus 53 degrees Celsius). Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.

On Aug. 28, NOAA’s Central Pacific Hurricane Center or CPHC noted that there were no coastal watches or warnings in effect. However, CPHC cautioned that interests in the Northwestern Hawaiian Islands should continue to monitor the progress of Lane.

Infrared data on Aug. 28 showed only small, scattered and short-lived puffs of deep convection in the northern semicircle. CPHC said those were located from 50 nautical miles northwest to over 100 nautical miles northeast and east of the center.

The University of Wisconsin- Cooperative Institute for Meteorological Satellite Studies or UW-CIMSS diagnosed vertical wind shear of over 69 mph (60 knots/111 kph) were affecting Tropical Depression Lane. Those winds are ripping away the cloud tops of strong storms near the low-level center and pushing them to the northeast.

At 5 a.m. EDT (0900 UTC) on Aug. 28 (11 p.m. HST, Aug. 27) the center of Tropical Depression Lane was located near latitude 18.4 degrees north and longitude 167.4 degrees west. The depression is moving toward the west near 7 mph (11 kph). Lane is forecast to move to the north-northwest. Maximum sustained winds were near 35 mph (55 kph) with higher gusts. Slight weakening is forecast during the next 48 hours.

Lane is forecast to become a remnant low pressure area later in the day. The remnant low is then expected to dissipate on Wednesday, Aug. 29 as it becomes absorbed into a developing extratropical low farther to the north.

For updated forecasts, visit the Central Pacific Hurricane Center website:  http://www.prh.noaa.gov/cphc/

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 27, 2018 – NASA Finds Wind Shear Slamming Tropical Cyclone Lane

Infrared satellite imagery shows scientists where the coldest cloud tops are located in a tropical cyclone and can give a clear picture of wind shear’s effects. NASA’s Aqua satellite data showed wind shear was pushing Tropical Depression Lane’s strongest storms east of its center. Despite the wind shear, Lane strengthened back into a tropical storm on Aug. 27.

Aqua image of Lane
At 8:15 a.m. EDT (1215 UTC) on Aug. 27,the MODIS instrument aboard NASA’s Aqua satellite found coldest cloud tops (red) were near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius), east of the center. Those storms were being pushed there by strong westerly winds. Credit: NASA/NRL

On Monday, August 27, 2018 there were no coastal watches or warnings in effect. However, NOAA’s Central Pacific Hurricane Center or CPHC said that interests in the Northwestern Hawaiian Islands should continue to monitor the progress of Lane.

At 8:15 a.m. EDT (1215 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard Aqua measured cloud top temperatures in Lane when it was a depression. Coldest cloud tops were near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius), east of the center. Those storms were being pushed there by strong westerly winds. Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.

Fortunately, that heavy rain is falling over open ocean waters. The infrared imagery showed that those strong storms were not reaching the Hawaiian Islands.

By 11 a.m. EDT (5 a.m. HST/1500 UTC), NOAA’s CPHC said that Lane regained strength and was upgraded from a tropical depression to a tropical storm. At that time the center of Tropical Storm Lane was located near latitude 18.9 degrees north and longitude 165.5 degrees west. That’s about 520 miles (835 km) west-southwest of Honolulu, Hawaii.

Lane is moving toward the west near 8 mph (13 km/h), and this motion is expected to continue today. A decrease in forward speed is expected tonight as Lane makes a turn toward the northwest. Lane is then expected to accelerate toward the northwest on Tuesday, Aug. 28 and Wednesday, Aug. 29.

Maximum sustained winds are near 40 mph (65 kph) with higher gusts.  Some short-term weakening is forecast, and Lane is expected to become a post-tropical remnant low by Tuesday. Lane may strengthen as an extratropical low as it passes over portions of the Northwestern Hawaiian Islands from Tuesday night through Thursday, Aug. 30.

For updated forecasts from the CPHC, visit: http://www.prh.noaa.gov/cphc

By Rob Gutro
NASA’s Goddard Space Flight Center,

Aug. 26, 2018 – Former Hurricane Lane Weakened to a Depression

Tropical Depression Lane continues to weaken and move away from Hawaii. Satellite imagery showed a much more disorganized system with light to moderate rainfall.

GPM image of Lane
A satellite image that combines infrared data from NOAA’s GOES-West satellite to show clouds with rainfall data from NASA/JAXA’s GPM satellite. The image provided a full picture of the depression and showed light rain (blue) was falling over the Hawaiian Islands on Aug. 26 at 1516 UTC (11: 16 a.m. EDT). Satellite imagery showed a much more disorganized system with light to moderate rainfall. Credit: NASA/NOAA/NRL

A satellite image that combines infrared data from NOAA’s GOES-West satellite to show clouds with rainfall data from NASA/JAXA’s GPM satellite. The image provided a full picture of the depression and showed light rain was falling over the Hawaiian Islands on Aug. 26 at 1516 UTC (11: 16 a.m. EDT).

Lingering moisture associated with Lane will produce heavy rainfall over portions of the main Hawaiian Islands today, Aug. 26, which could lead to additional flash flooding and landslides.

On Aug. 26, there were no coastal watches or warnings in effect. NOAA’s Central Pacific Hurricane Center or CPHC noted that interests in the Northwestern Hawaiian Islands should continue to monitor the progress of Lane.

At 11 a.m. EDT (5 a.m. HST/1500 UTC), the center of Tropical Depression Lane was located near latitude 19.1 North, longitude 162.2 West. The depression is moving toward the west near 10 mph (17 km/h), and this general motion is expected to continue into Monday, Aug. 27. A brief slowing in forward motion is expected Monday night as Lane makes a turn toward the northwest. Lane is then expected to accelerate northwestward by Tuesday as it transitions to an extratropical low.

Maximum sustained winds are near 35 mph (55 kph) with higher gusts. Some weakening is forecast during the next 48 hours, and Lane is expected to become a post-tropical remnant low later today or tonight. In a couple of days, Lane may develop into a gale force extratropical low as it passes over portions of the Northwestern Hawaiian Islands.

For updated forecasts, visit: http://www.prh.noaa.gov/cphc

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 25, 2018 – Lane’s Hawaii Soaking Continues as NASA Analyzes the Tropical Storm

By Aug. 25, Hurricane Lane had weakened to a tropical storm. Despite the drop in strength, the heavy rains persist over the Hawaiian Islands. NASA’s Aqua and GPM satellites provided a look at the location of Lane and the rainfall rates. NOAA’s Central Pacific Hurricane Center or CPHC said at 8 a.m. EDT (2 a.m. HST) today, Saturday, August 25, 2018, “Lane’s outer rain bands producing severe flooding across parts of the Hawaiian Islands.”

Aqua image of Lane
On Aug. 25, The MODIS instrument aboard NASA’s Aqua satellite showed that Lane was centered west of the Big Island (Island of Hawaii), while a band of thunderstorms stretched east bringing more drenching rainfall over the Island of Hawaii. Credit: NASA/NRL

A Tropical Storm Warning is in effect for Oahu, Maui County…including the islands of Maui, Lanai, Molokai and Kahoolawe and Hawaii County A Tropical Storm Watch is in effect for Kauai County…including the islands of Kauai and Niihau.

On Aug. 25, The MODIS instrument aboard NASA’s Aqua satellite showed that Lane was centered west of the Big Island (Island of Hawaii), while a band of thunderstorms stretched east bringing more drenching rainfall over the Island of Hawaii.

GPM image of Lane
NASA and JAXA’s GPM satellite measured rainfall rates at 12:46 a.m. EDT (0446 UTC) on Aug. 25 and found the southwestern tip of the Island of Hawaii and the west coast were receiving rainfall at a rate over 1.2 inches per hour. The GPM was coupled with an infrared image from NOAA’s GOES-West satellite to show the clouds of the tropical storm and form and entire picture. Credit: NASA/JAXA/NOAA

NASA and the Japan Aerospace Exploration Agency’s Global Precipitation Measurement mission or GPM satellite measured rainfall rates at 12:46 a.m. EDT (0446 UTC) and found the southwestern tip of the Island of Hawaii and the west coast were receiving rainfall at a rate over 1.2 inches per hour. The GPM was coupled with an infrared image from NOAA’s GOES-West satellite to show the clouds of the tropical storm and form and entire picture.

NOAA’s CPHC said “Lane’s outer rain bands will produce excessive rainfall this weekend, which could lead to additional flash flooding and landslides. Lane is expected to produce total rain accumulations of 10 to 20 inches in some areas. Localized storm total amounts well in excess of 40 inches have already been observed along the windward side of the Big Island.”

At 6 a.m. EDT (2 a.m. HST/1200 UTC), the center of Tropical Storm Lane was located near latitude 19.5 degrees north and longitude 158.4 degrees west. Maximum sustained winds are near 65 mph (100 kph) with higher gusts. Additional weakening is forecast through Sunday night. Tropical-storm-force winds extend outward up to 130 miles (215 km) from the center.

Lane is moving toward the north-northwest near 3 mph (6 kph), and this general motion is expected to continue through this morning. This will likely be followed by a turn toward the west with an increase in forward speed starting later today or tonight. This westward motion is forecast to continue through Sunday. On the forecast track, the center of Lane will pass south of Kauai and Niihau later today.

The CPHC forecast noted that Tropical storm conditions are still expected in and near outer rain bands that will affect Oahu, Maui County and the Big Island today. Tropical storm conditions are possible on Kauai starting later today. Large swells generated by Lane will impact the Hawaiian Islands. These swells will produce high surf along exposed south and east shorelines through this morning. Isolated tornados are possible through this morning across parts of the Big Island, Maui County and Oahu.

For updated forecasts, visit: http://www.prh.noaa.gov/cphc

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 24, 2018 (#2) – Multiple NASA Instruments Capture Hurricane Lane

Instruments on NASA’s Terra and Aqua satellites were watching as Hurricane Lane — a category 2 storm as of Friday, Aug. 24 — made its way toward Hawaii.

NASA’s Multi-angle Imaging SpectroRadiometer (MISR) captured images of Lane on just before noon local time on Aug. 24. MISR, flying onboard NASA’s Terra satellite, carries nine cameras that observe Earth at different angles. It takes approximately seven minutes for all the cameras to observe the same location, and the motion of the clouds during that time is used to compute the wind speed at the cloudtops.

The image shows the storm as viewed by the central, downward-looking camera. Also included is a stereo anaglyph, which combines two of the MISR angles to show a three-dimensional view of Lane. The image has been rotated in such a way that north is at the bottom. You will need red-blue glasses to view the anaglyph (with the red lens placed over your left eye).

MISR image of Lane
Stereo Anaglyph using MISR data shows 3D view of Hurricane Lane on August 24. Red-blue 3D glasses required.  Credits: NASA/GSFC/LaRC/JPL-Caltech, MISR Team

MISR was built and is managed by NASA’s Jet Propulsion Laboratory in Pasadena, California, for NASA’s Science Mission Directorate in Washington. JPL is a division of Caltech. The Terra spacecraft is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland. The MISR data were obtained from the NASA Langley Research Center Atmospheric Science Data Center in Hampton, Virginia.

NASA’s Atmospheric Infrared Sounder (AIRS) captured Hurricane Lane when the Aqua satellite passed overhead on Aug. 22 and 23. The infrared imagery represents the temperatures of cloud tops and the ocean surface. Purple shows very cold clouds high in the atmosphere above the center of the hurricane, while blue and green show the warmer temperatures of lower clouds surrounding the storm center. The orange and red areas, away from the storm, have almost no clouds, and the ocean shines through. In the Aug. 22 image, a prominent eye is also visible. No eye is visible on the Aug. 23 image, either because it was too small for AIRS to detect or it was covered by high, cold clouds.

AIRS image of Lane
This image shows Hurricane Lane as observed by the Atmospheric Infrared Sounder (AIRS) instrument on NASA’s Aqua satellite on Thursday, August 22.

AIRS, in conjunction with the Advanced Microwave Sounding Unit (AMSU) senses emitted infrared and microwave radiation from Earth to provide a three-dimensional look at Earth’s weather and climate. Working in tandem, the two instruments make simultaneous observations all the way down to Earth’s surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, three-dimensional map of atmospheric temperature and humidity, cloud amounts and heights, greenhouse gas concentrations, and many other atmospheric phenomena. Launched into Earth orbit in 2002, the AIRS and AMSU instruments fly onboard NASA’s Aqua spacecraft and are managed by JPL.

AIRS image of Lane
This image shows Hurricane Lane as observed by the Atmospheric Infrared Sounder (AIRS) instrument on NASA’s Aqua satellite on Thursday, August 23. Credits: NASA/JPL-Caltech

More information about MISR is available at these sites:  https://www-misr.jpl.nasa.gov/

https://eosweb.larc.nasa.gov/project/misr/misr_table

More information about AIRS is at: https://airs.jpl.nasa.gov/

Esprit Smith
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-4269
esprit.smith@jpl.nasa.gov

Aug. 24, 2018 (#1) – NASA Looks at Heavy Rainmaker in Hurricane Lane

Cloud top temperatures provide scientists with an understanding of the power of a tropical cyclone. NASA’s Aqua satellite observed Hurricane Lane in infrared light to those temperatures.

Aqua image of Lane
On Aug. 23 at 7:35 p.m. EDT (2335 UTC) NASA’s Aqua satellite found the coldest temperatures of the strongest thunderstorms (yellow) in Hurricane Lane were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius) north of the center. They were embedded in a large area of storms (red) that circled the eye where cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). Credits: NRL/NASA

The higher the cloud tops, the colder and the stronger they are. So infrared light as that gathered by the MODIS instrument can identify the strongest sides of a tropical cyclone. Wherever cloud top temperatures are as cold as or colder than minus 63 degrees Fahrenheit (minus 53 degrees Celsius), those storms have the potential to drop heavy rain.

Hurricane Lane’s cloud top temperatures were colder than that, meaning that the storm has a potential to drop even heavier rainfall. Rainfall is the biggest threat from Lane.

On Aug. 23 at 7:35 p.m. EDT (2335 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite found the coldest temperatures of the strongest thunderstorms in Hurricane Lane were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius) north of the center. They were embedded in a large area of storms that circled the eye where cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius).

Rainfall Expected

On Aug. 24, NOAA’s Central Pacific Hurricane Center or CPHC noted that catastrophic flooding occurring on the big island of Hawaii. CPHC said “Rain bands will continue to overspread the Hawaiian Islands well ahead of Lane. Excessive rainfall associated with this slow moving hurricane will continue to impact the Hawaiian Islands into the weekend, leading to catastrophic and life-threatening flash flooding and landslides. Lane is expected to produce total rain accumulations of 10 to 20 inches, with localized amounts up to 40 inches possible over portions of the Hawaiian Islands. Over 30 inches of rain has already fallen at a couple locations on the windward side of the Big Island.”

The slow movement of Lane also greatly increases the threat for prolonged heavy rainfall and extreme rainfall totals. This is expected to lead to major, life-threatening flash flooding and landslides over all Hawaiian Islands.

Warnings and Watches

A Hurricane Warning is in effect for Oahu, Maui County…including the islands of Maui, Lanai, Molokai and Kahoolawe. A Tropical Storm Warning is in effect for Hawaii County.

A Hurricane Watch is in effect for Kauai County…including the islands of Kauai and Niihau.

Key Messages and Cautions from NOAA’s CPHC

Lane will pass dangerously close to the main Hawaiian Islands as a hurricane on Friday, and is expected to bring damaging winds. The slow movement of Lane also greatly increases the threat for prolonged heavy rainfall and extreme rainfall totals. Large and damaging surf can be expected along exposed shorelines, especially along south and west facing coasts, with localized storm surge exacerbating the impacts of a prolonged period of damaging surf.

Although the official forecast does not explicitly indicate Lane’s center making landfall over any of the islands, this remains a very real possibility. Even if the center of Lane remains offshore, severe impacts could still be realized as they extend well away from the center.

Wind Shear Affecting Lane

CPHC said, “Hurricane Lane is beginning to show some signs of slow weakening due to wind shear of over 20 knots from the southwest according to the SHIPS and UW-CIMSS analyses. There is no eye evident in satellite imagery, which is likely a result of these hostile conditions.”

Lane’s Location on Aug. 24

At 11 a.m. EDT (5 a.m. HST/1500 UTC), the center of Hurricane Lane was located near latitude 18.7 degrees north and longitude 158.0 degrees west.

Lane is moving toward the north near 5 mph (7 kph), and this general motion is expected to continue through tonight. A turn toward the west is anticipated on Saturday, with an increase in forward speed. On the latest forecast track, the center of Lane will move dangerously close to portions of the central Hawaiian Islands later today, Aug. 24 and tonight.

Maximum sustained winds are near 110 mph (175 kph) with higher gusts. Lane is now Category 2 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some additional weakening is forecast later today and tonight, but Lane is expected to remain a dangerous hurricane as it approaches the islands. Further weakening is expected on Saturday, Aug.25. The estimated minimum central pressure is 962 millibars.

For updated forecasts, visit: http://www.prh.noaa.gov/cphc

By Rob Gutro
NASA’s Goddard Space Flight Center

Aug. 23, 2018 – NASA Analyzes a Solid Ring of Cold Cloud Tops Hurricane Lane

An infrared look by NASA’s Terra satellite provided forecasters with temperature data in the Category 4 hurricane near Hawaii. Terra data showed a large ring of coldest and most powerful storms around Hurricane Lane’s eye on Aug. 23.

Terra image of Lane
Cold temperatures found in the thunderstorms inside Lane On Aug. 23 at 4:15 a.m. EDT (0815 UTC) NASA’s Terra satellite found the coldest temperatures of the strongest thunderstorms (yellow) in Hurricane Lane were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius) northeast and southwest of the eye. They were embedded in a large area of storms (red) that circled the eye where cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). Credits: NRL/NASA

NOAA’s Central Pacific Hurricane Center or CPHC noted that a Hurricane Warning is in effect for Oahu, Maui County including the islands of Maui, Lanai, Molokai and Kahoolawe and Hawaii County. A Hurricane Watch is in effect for Kauai County, including the islands of Kauai and Niiha.

On Aug. 23 at 4:15 a.m. EDT (0815 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Terra satellite analyzed cloud top temperatures in infrared light. MODIS found cloud top temperatures of the strongest thunderstorms northeast and southwest of the eye were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius). They were embedded in a large area or storms that circled the eye where cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius).

Cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain. Rainfall is expected to be the biggest threat from Lane.

CPHC said, “The cloud-filled eye continues to be surrounded by a solid ring of cold cloud tops, with lightning bursts persisting in the northern eye wall for the last several hours.”

CPHC also noted, “Excessive rainfall associated with Lane will impact the Hawaiian Islands into the weekend, leading to significant and life-threatening flash flooding and landslides. Lane is expected to produce total rain accumulations of 10 to 20 inches, with localized amounts in excess of 30 inches over the Hawaiian Islands.”

At 8 a.m. EDT (2 a.m. HST/1200 UTC) on Aug. 23, the eye of Hurricane Lane was located by satellite and radar near latitude 16.5 degrees north and longitude 157.3 degrees west.

NOAA’s CPHC said, “Lane is moving toward the northwest near 7 mph (11 kph). This general motion is expected to continue today, with a gradual turn toward the north-northwest. On Friday, a turn toward the north is anticipated as Lane’s forward motion slows even more. A turn back toward the west is expected on Saturday. On the forecast track, the center of Lane will move very close to or over the main Hawaiian Islands later today through Friday (Aug. 24).”

Maximum sustained winds are near 130 mph (215 kph) with higher gusts. Hurricane-force winds extend outward up to 40 miles (65 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km).

Lane is a powerful category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale.

CPHC said, “Some weakening is forecast during the next day or so, with more significant weakening thereafter. Lane is expected to remain a hurricane as it approaches the islands.”

For updated forecasts, visit: http://www.prh.noaa.gov/cphc

By Rob Gutro
NASA’s Goddard Space Flight Center

For earlier information on Lane go to:  https://www.nasa.gov/feature/goddard/2018/lane/

Soulik (Northwestern Pacific Ocean) 2018

Aug. 24, 2018 – NASA Tracks Tropical Storm Soulik into the Sea of Japan

NASA’s Aqua satellite flew over Tropical Storm Soulik after it moved into the Sea of Japan and saw that wind shear was adversely affecting the storm.

On Aug. 24 at 12:40 a.m. EDT (0430 UTC), NASA’s Aqua satellite provided a visible image of Tropical Storm Soulik after it moved off the Korean Peninsula and into the Sea of Japan. Credits: NASA/NRL

On Aug. 24 at 12:40 a.m. EDT (0430 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard Aqua captured a visible light image of Soulik after it moved off the Korean Peninsula.  The image showed the bulk of clouds were being pushed north of the low level center, as the southern quadrant was almost devoid of clouds, except for a small ring around the center.

At 11 a.m. EDT (1500 UTC) on Aug. 24, the center of Tropical Storm Soulik was located near 41.0 degrees north latitude and 133.0 degrees east longitude. That’s about 349 nautical miles northeast of Yongsan. The Yongsan Garrison located in the Yongsan District of Seoul, South Korea.

Soulik is speeding to the northeast at 36 knots (41 mph/67 kph) and maximum sustained winds are near 35 knots (40 mph/62 kph) with higher gusts.

The Joint Typhoon Warning Center or JTWC expects Soulik to move rapidly across the Sea of Japan and will become extra-tropical before reaching Hokkaido.

By Rob Gutro
NASA Goddard Space Flight Center

For earlier info about Soulik go to: https://www.nasa.gov/feature/goddard/2018/soulik-northwestern-pacific