Aug. 31, 2020 – NASA Finds Typhoon Maysak Moving Near Okinawa, Japan
Typhoon Maysak continued to move through the Northwestern Pacific and was closing in on Japan’s Okinawa Island when NASA’s Terra satellite obtained a visible image of the storm. Maysak’s eye is not expected to go over the island, but pass just west of it.
NASA’s Terra satellite provided a visible image to forecasters of Typhoon Maysak as it neared Okinawa Island, Japan on Aug. 31. Image Courtesy: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).
The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite captured a visible image of Typhoon Maysak. Imagery showed the eye of the storm appeared filled with high clouds, as powerful bands of thunderstorm circled it. Bands of thunderstorms from the south were spiraling into the low-level center.
On Aug. 31 at 5 a.m. EDT (0900 UTC), Typhoon Maysak was located about 144 nautical miles south of Kadena Air Base, Okinawa Island, Japan. It was moving to the north-northwest and had maximum sustained winds near 100 knots (115 mph/185 kph).
Maysak’s center is expected to pass just west of Okinawa within 24 hours. The storm is expected to make landfall in southern South Korea and will start to become extra-tropical.
About NASA’s Worldview and Terra Satellite
NASA’s Earth Observing System Data and Information System (EOSDIS) Worldview application provides the capability to interactively browse over 700 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated within three hours of observation, essentially showing the entire Earth as it looks “right now.”
NASA’s Terra satellite is one in a fleet of NASA satellites that provide data for hurricane research.
Tropical cyclones/hurricanes are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.
Aug. 28, 2020 – NASA Terra Satellite Sees Development of Tropical Storm Maysak
NASA infrared imagery revealed several areas of strong thunderstorms around the center of the recently organized Tropical Storm Maysak.
On Aug. 28 at 9:15 a.m. EDT (1315 UTC) the MODIS instrument that flies aboard NASA’s Terra satellite revealed the most powerful thunderstorms (yellow) minus 80 degrees Fahrenheit (minus 62.2 degrees Celsius) near Maysak’s center and over the Gulf of California. Surrounding that area were cloud top temperatures were as cold as (red) minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius). All of those areas were generating heavy rain. Credit: NASA/NRL
Tropical Depression 10W formed during the early morning hours on Aug. 28 and quickly organized and strengthened into a tropical storm.
Infrared Data Provides a Temperature Check
Infrared data provides temperature information, and the strongest thunderstorms that reach highest into the atmosphere have the coldest cloud top temperatures.
On Aug. 28 at 9:15 a.m. EDT (1315 UTC), the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA’s Terra satellite captured an infrared image of cloud top temperatures in Maysak that showed a quick burst of strength. MODIS found the powerful thunderstorms that developed were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 degrees Celsius) near Maysak’s center. Surrounding that area were cloud top temperatures were as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius). All of those areas were generating heavy rain. The storm also appeared somewhat elongated from west to east.
Less than 2 hours later, infrared data showed those cloud tops were cooling, meaning they dropped in altitude. At 11 a.m. EDT (1500 UTC), the Joint Typhoon Warning Center noted, “Satellite imagery depicts an elongated low level circulation center partially obscured by deep convection [wind] sheared slightly to the southwest. Cloud tops have cooled significantly over the past 6 hours as the convection has continued to consolidate.”
Maysak’s Status on Aug. 28, 2020
At 11 a.m. EDT (1500 UTC), the center of Tropical Storm Maysak was located near latitude 16.3 degrees north and longitude 129.5 degrees east. That is about 619 miles south of Kadena Air Base, Okinawa Island, Japan. Maysak is moving to the west-southwest and has maximum sustained winds near 35 knots (40 mph).
Maysak is forecast to move northwest and pass just to the west of Okinawa Island on Aug. 31 as it tracks north.
NASA Researches Earth from Space
For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America’s leadership in space and scientific exploration.
Sep. 01, 2020 – NASA’s IMERG Analyzed Heavy Rains from Hurricanes Laura and Marco
The northern Gulf Coast, specifically Louisiana, saw two tropical cyclones make landfall in the same week just days apart. NASA’s IMERG surface rainfall accumulations were calculated for the period 22 to 27 August 2020 for both Hurricanes Marco and Laura. The two systems, however, could not have been more different when they arrived.
IMERG data on Marco and Laura. Image credit: NASA/JAXA/IMERG, Steve Lang
Marco’s History and Track
Despite forming a day later, Marco was the first system to make landfall on the Gulf Coast. Marco originated from a tropical easterly wave that was moving from the central to the western Caribbean. After becoming a tropical depression (TD) on August 20, TD #14 turned northwestward the following day as it approached the coast of Central America and moved into the northwest Caribbean.
According to the National Hurricane Center (NHC), TD #14 reached tropical storm intensity on the night of the 21st and named Marco. Marco remained over warm open water as it passed through the Yucatan Straight and into the Gulf of Mexico on the afternoon of the 22nd. Marco was now a strong tropical storm with sustained winds reported at 65 mph by NHC and seemed poised to intensify.
However, the warm waters were offset by the effects of southwesterly wind shear, which were to become a major inhibiting factor as Marco moved through the Gulf of Mexico.
Although the wind shear kept Marco from really intensifying, the warm Gulf waters supported enough convection for Marco to reach hurricane intensity around midday on Sunday the 23rd. By now Marco was in the central Gulf and moving north between a ridge of high pressure to the east and an upper-level trough over the western Gulf. However, as Marco continued northward the wind shear increased, pushing the thunderstorms that were fueling the system along with most of the rain away from the center off to the northeast, causing Marco to weaken back down to a tropical storm that very same evening.
On the 24th, as it neared the northern Gulf Coast, Marco continued to weaken and slow down as high pressure to the east built westward, blocking Marco’s path and forcing the cyclone to turn westward. The center of circulation just made landfall near the mouth of the Mississippi at 6:00 pm CDT on Monday the 24th with sustained winds reported at 40 mph by NHC before being shunted westward back over open water and weakening further. By now, the center was essentially devoid of thunderstorms with the bulk of the rain falling well east of the center.
NASA Rainfall Accumulations on Marco
IMERG surface rainfall accumulations were compiled for the period 22 to 27 August 2020 for the southeastern U.S., Gulf of Mexico, the northwest Caribbean and adjacent regions. Accumulations include the effects from both Laura and Marco. However, the rainfall due to Marco is evidenced by its north-south orientation and generally extends from the west-central Caribbean up through the Yucatan Strait and the eastern Gulf of Mexico and into the Florida Panhandle.
The heaviest rainfall totals due to Marco were just offshore and along the coast of the Florida Panhandle and reached up to 225 mm (~9 inches, shown in dark red) while a good portion of the Florida Panhandle is estimated to have received at least 75 to 100 mm (~3 to 4 inches, shown in bright green and yellow). Rainfall totals near the mouth of the Mississippi where the center made landfall are much lower and reflects the storm’s asymmetric structure due to the strong wind shear where most of the thunderstorms and associated rainfall occurred well northeast of the center.
Laura’s History and Track
Laura too originated from an easterly wave but began as TD #13 well out into the central tropical Atlantic on the night of August 19. Over the next couple of days, despite passing over warm water, TD #13 was held in check by a combination of mid-level wind shear and dry air that kept the system poorly organized. However, as it neared the Leeward Isles on the 21st, it finally reached minimum tropical storm intensity and named Laura.
Laura then passed through the Leeward Islands as a weak tropical storm later that same day. As it approached Puerto Rico on the 22nd, Laura was still unorganized, and although the wind shear abated, Laura was now inhibited by its close proximity to land. After passing very near the southwest coast of Puerto Rico, Laura crossed directly over the island of Hispaniola on the night of the 22nd; however, despite being over land, Laura continued to generate deep convection and emerged off the west coast of Haiti with sustained winds reported at 50 mph by NHC on the morning of the 23rd.
Laura gained a little strength before crossing over southeastern Cuba on the night of the 23rd; again, despite being over land, Laura continued to tap into the warm waters off the south coast of Cuba and actually intensified slightly. On the morning of the 24th, Laura re-emerged over open water south of Cuba.
At this point, another key factor came into play. The ridge of high pressure north of Laura that was steering the storm expanded westward, keeping the center well over water and further away from the south coast of Cuba. Despite this, northerly wind shear, drier air and some land interaction initially weakened the storm slightly as it paralleled the south coast of Cuba. However, as Laura neared and crossed western Cuba on the evening of the 24th, it was already showing signs of becoming better organized though it remained at tropical storm intensity.
When Laura emerged out into the southeast Gulf of Mexico early on the morning of the 25th, it did so over deep, warm water in a humid, relatively low wind-shear environment, the perfect conditions for intensification. Almost immediately, strong convection fired up near Laura’s core, lowering the central pressure, and by 7:15 a.m. CDT on Tuesday August 25th, Laura was a Category 1 hurricane. Now well organized and in ideal conditions for strengthening, Laura was primed for further, rapid intensification, which is exactly what happened.
Over the next 36 hours, as Laura gradually turned northward around the western edge of a high pressure ridge across Florida and headed for the northern Gulf Coast, it underwent a rapid deepening cycle. Reports from NHC showed that maximum sustained winds increased from 75 to 150 mph over this period, taking Laura from Category 1 to a Category 4 hurricane.
By this time, Laura was very near to the coast of western Louisiana where it then made landfall near Cameron, Louisiana at 1:00 a.m. CDT at the same 150 mph intensity. A wind gust to 128 mph was reported at the Lake Charles Regional Airport. It is estimated that Laura maintained hurricane intensity for the next 10 hours as it moved northward into northern Louisiana.
NASA Rainfall Accumulations on Laura
IMERG surface rainfall accumulations from Laura on the northern Gulf Coast were actually lower than they are for Marco and generally range from over 50 to 100 mm (~2 to 4 inches, shown in green and yellow) with local pockets of higher amounts (shown in orange) extending across most of Louisiana and Arkansas. Rainfall amounts depend more on system speed than intensity; while Marco slowed down near the coast, Laura continued to push northward. However, elsewhere in the Caribbean, IMERG estimates show from 125 to over 225 mm (~5 to over 9 inches, shown in orange and darker red) of rain over the southern half of Hispaniola, where a total of 35 fatalities were reported to due to the storm, 31 of which were in Haiti. So far, 22 deaths are being blamed on Laura in the US, 14 of those in Louisiana.
About IMERG
The near-real-time rain estimate comes from the NASA’s Integrated Multi-satellitE Retrievals for GPM (IMERG) algorithm, which combines observations from a fleet of satellites, in near real time, to provide near-global estimates of precipitation every 30 minutes. This satellite-based rain estimate is somewhat coarse in resolution and can miss short-lived, intense storm-cells, but the IMERG algorithm often does captures the large-scale features of storms wherever they form in the world. While the United States is fortunate to have a network of ground radars that can provide higher-resolution precipitation estimates, in other parts of the world, notably over most of the world’s oceans, the IMERG rain estimate is an important reference point.
This near-real time rain estimate comes from the NASA’s IMERG algorithm, which combines observations from a fleet of satellites, in near-real time, to provide near-global estimates of precipitation every 30 minutes. By combining NASA precipitation estimates with other data sources, we can gain a greater understanding of major storms that affect our planet.
IMERG fills in the “blanks” between weather observation stations. IMERG satellite-based rain estimates can be compared to that from a National Weather Service ground radar. Such good detection of large rain features in real time would be impossible if the IMERG algorithm merely reported the precipitation observed by the periodic overflights of various agencies’ satellites. Instead, what the IMERG algorithm does is “morph” high-quality satellite observations along the direction of the steering winds to deliver information about rain at times and places where such satellite overflights did not occur. Information morphing is particularly important over the majority of the world’s surface that lacks ground-radar coverage.
Aug. 28, 2020 – Terra MISR Used to Visualize Cloud-top Heights from Hurricane Laura in 3D
MISR data was used to create 3-D images of Laura’s clouds. Credit: NASA
On August 25th, Several days before Hurricane Laura made landfall as a destructive category 4 storm in Louisiana, NASA’s Terra satellite flew over Laura in the Gulf of Mexico. Using its Multi-angle Imaging SpectroRadiometer (MISR) instrument, the satellite collected data on wind speeds and cloud-top heights as the storm intensified and moved northwest towards the U.S. Gulf Coast.
Aug. 28, 2020 – NASA-NOAA Satellite Nighttime Imagery Tracks Tropical Depression Laura Over U.S.
A new animation of nighttime imagery from NASA-NOAA’s Suomi NPP satellite followed the path of former Hurricane Laura from its landfall in southwestern Louisiana to its movement over the Mississippi Valley.
This animation of nighttime imagery from NASA-NOAA’s Suomi NPP satellite shows track of Hurricane Laura from the landfall northeast over Louisiana to the Mississippi Valley from Aug.23 to 28, 2020 (0000 UTC). Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)
As Laura tracks across the eastern U.S., it is generating heavy rain and has triggered watches.
On Aug. 28, Flash Flood Watches were posted for portions of northeast Arkansas, southeast Missouri, western Kentucky and Tennessee, northern of Mississippi, and northwest Alabama.
NASA’s Night-Time Imagery Tracks Laura
The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided days of infrared nighttime imagery of the now former hurricane Laura. Using the Worldview Application at NASA’s Goddard Space Flight Center, Greenbelt, Md. an animation was created of nighttime imagery from Aug. 23 to 28, 2020 (0000 UTC) that showed the track of Hurricane Laura from the landfall and movement from southwestern Louisiana to the Mississippi Valley.
NASA-NOAA’s Suomi NPP satellite captured a nighttime image of Tropical Depression Laura during the early morning hours of Aug. 28 as its center exited Arkansas and was moving in an easterly direction over the U.S. toward the Atlantic Ocean. What appears to be blurred lighting is a result of the clouds associated with Laura over an area in the imagery. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)
Tropical Depression Laura’s Status on Aug. 28
At 11 a.m. EDT (1500 UTC) on Aug. 28, NOAA’s Weather Prediction Center (WPC) noted the center of Tropical Depression Laura was located near latitude 36.6 north, longitude 90.5 west. That puts the center about 85 miles (140 km) northwest of Memphis, Tenn. and about 105 miles (170 km) west-southwest of Paducah, Kentucky. The depression was moving toward the east-northeast near 20 mph (31 km/h) and this motion is expected to continue as Laura tracks along and south of the Ohio Valley through tonight. Maximum sustained winds were near 30 mph (45 kph) with higher gusts. The estimated minimum central pressure is 1001 millibars.
Hazards Laura Brings Along its Path
NOAA’s WPC provided a look at the hazards that Tropical Depression Laura is expected to bring along its path toward the Atlantic Ocean over the next 2 days: “Expect 1 to 3 inches, with isolated 5-inch totals from western and central Kentucky and Tennessee into northern Alabama and Mississippi. One to 2 inches, with isolated 4-inch totals are possible over southern parts of Louisiana, Mississippi, and Alabama. By Saturday, 1 to 3 inches of rain is forecast from the central and southern Appalachians to the Mid-Atlantic States. This rainfall will continue to contribute to isolated flash and urban flooding, and overflow of small streams and creeks across the aforementioned regions. Minor to moderate river flooding is occurring or forecast in Louisiana and Arkansas.
Gusty winds of 25-30 mph will accompany Laura’s circulation as it moves toward the Lower Ohio Valley through the afternoon. Stronger gusts are possible within thunderstorms.
A few tornadoes remain possible, mainly over parts of Mississippi, Tennessee and southern Kentucky. The risk for a couple of tornadoes should redevelop Saturday afternoon and evening over parts of the mid-Atlantic from Virginia to North Carolina.”
Forecast for Laura
Eventually, the remains of Laura will cross the central Appalachians Saturday, before becoming absorbed by an approaching cold front that is forecast to move off the mid-Atlantic coastline by late Saturday.
About NASA’s EOSDIS Worldview
NASA’s Earth Observing System Data and Information System (EOSDIS) Worldview application provides the capability to interactively browse over 700 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated within three hours of observation, essentially showing the entire Earth as it looks “right now.”
NASA Researches Earth from Space
For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America’s leadership in space and scientific exploration.
Aug. 28, 2020 – NASA’s captures powerful Hurricane Laura over Louisiana
As it moved inland heading north over western Louisiana, Laura was overflown by the NASA / JAXA GPM Core Observatory satellite at 10:00 p.m. CDT on Wednesday August 26th, shortly before the storm made landfall, then again at 8:11 a.m. CDT on Thursday August 27th, about 7 hours after making landfall, as shown in the animation below.
Rainfall rates derived directly from the GPM Microwave Imager (GMI) and Dual-frequency Precipitation Radar (DPR) instruments show heavy rain (in red) pushing up into northern Louisiana and southern Arkansas as strong southerly winds drew moisture from the Gulf of Mexico on the eastern side of the storm’s strong cyclonic circulation. With its ability to penetrate through the clouds using active radar, the DPR also provided a detailed look at Laura’s structure. Precipitation cloud-top heights from the DPR (highlighted in blue, indicating frozen precipitation) show Laura still had the overall structure of a powerful hurricane, as evidenced by both the symmetry of the outer rain bands that still wrap completely around the storm, as well as the residual structure of a strong core near the center containing elements of very heavy rain (shown in pink). At the time of this GPM overpass, Laura’s maximum sustained winds were still reported at 100 mph by the National Hurricane Center, the equivalent of a category 2 hurricane.GPM data is archived at https://pps.gsfc.nasa.gov/
Text by Steve Lang, Jacob Reed (NASA Goddard Space Flight Center)
GPM overpass visualization by Alex Kekesi (NASA Goddard Scientific Visualization Studio)
IMERG rainfall visualization by Owen Kelley, Jason West (NASA Precipitation Processing System)
Aug. 28, 2020 – NASA Terra Satellite Examines Tropical Storm Hernan’s Relocated Center
NASA infrared imagery revealed a burst of strength in Tropical Storm Hernan, located over the Gulf of California. At 12:30 a.m. EDT, NOAA’s National Hurricane Center or NHC noted that recent satellite-based wind data indicated Hernan was located northeast of previous estimates.
On Aug. 28 at 1 a.m. EDT (0500 UTC) the MODIS instrument that flies aboard NASA’s Terra satellite revealed the most powerful thunderstorms (yellow) minus 80 degrees Fahrenheit (minus 62.2 degrees Celsius) near Hernan’s center and over the Gulf of California. Surrounding that area were cloud top temperatures were as cold as (red) minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius). All of those areas were generating heavy rain. Credit: NASA/NRL
The body of water located between the Baja California Peninsula and the Mexican mainland is known as the Gulf of California. It is a marginal sea of the Pacific Ocean.
NHC noted late on Aug. 27, that Hernan appeared poorly organized, and despite a burst of strength, the storm weakened to a depression.
Infrared Data Provides a Temperature Check
Infrared data provides temperature information, and the strongest thunderstorms that reach highest into the atmosphere have the coldest cloud top temperatures.
On Aug. 28 at 1 a.m. EDT (0500 UTC), the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA’s Terra satellite captured an infrared image of cloud top temperatures in Hernan that showed what appears to be its final burst of strength. MODIS found the powerful thunderstorms that developed were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 degrees Celsius) near Hernan’s center and over the Gulf of California. Surrounding that area were cloud top temperatures were as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius). All of those areas were generating heavy rain, but within a couple of hours, they diminished.
Hernan Weakened to a Depression
The National Hurricane Center (NHC) noted at 5 a.m. EDT that Hernan had weakened to a depression and strong thunderstorms had weakened. NHC said, “Shortly after the release of the previous advisory, microwave imagery from a WindSat overpass showed no indication of a well-defined center near Hernan’s estimated location. However, there was a hint of a small vortex well to the northeast. Confidence is therefore fairly high that Hernan has persisted as a tropical cyclone, at least through 12 a.m. EDT (0400 UTC) this morning.” WindSat is the primary instrument aboard the Coriolis mission satellite, which is jointly sponsored by the U.S. Dept. of Defense Space Test Program and the U.S. Navy.
Hernan’s Status on Aug. 28, 2020
At 11 a.m. EDT (1500 UTC), the center of Tropical Depression Hernan was located near latitude 23.4 north, longitude 109.1 west, about 60 miles (100 km) northeast of the southern tip of Baja California, Mexico. The depression is moving toward the west-northwest near 21 mph (33 kph) and this motion is expected to continue through tonight. Maximum sustained winds have decreased to near 35 mph (55 kph) with higher gusts. Additional weakening is forecast, and Hernan is expected to degenerate to a remnant low-pressure area tonight. The remnants are expected to dissipate on Saturday. The estimated minimum central pressure is 1006 millibars.
Forecast from NHC
Based on decreasing satellite intensity estimates, Hernan was downgraded to a tropical depression. Additional weakening is forecast, and Hernan is expected to degenerate to a remnant low pressure area as it moves over the Baja California peninsula later today and tonight. The system is then expected to weaken to a trough (elongated area of low pressure) on Saturday.
NASA Researches Earth from Space
For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America’s leadership in space and scientific exploration.
Aug. 28, 2020 – NASA Sees Wind Shear Still Battering Tropical Storm Iselle
NASA infrared imagery shows wind shear continued to batter Tropical Storm Iselle in the Eastern Pacific Ocean for the second day.
On Aug. 28 at 2:40 a.m. EDT (0640 UTC) the MODIS instrument that flies aboard NASA’s Terra satellite revealed the most powerful thunderstorms (yellow) minus 80 degrees Fahrenheit (minus 62.2 degrees Celsius) near the center. Wind shear was pushing the rest of the storms to the west. Some cloud top temperatures were as cold as (red) minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) and were also dropping large amounts of rain. Credit: NASA/NRL
NASA’s Infrared Data Finds Push of Winds
Tropical cyclones are made up of hundreds of thunderstorms, and infrared data can show where the strongest storms are located. That is because infrared data provides temperature information, and the strongest thunderstorms that reach highest into the atmosphere have the coldest cloud top temperatures.
On Aug. 28 at 2:40 a.m. EDT (0640 UTC), the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA’s Terra satellite captured an infrared image of cloud top temperatures in Iselle. Iselle continues to produce deep convection and strong thunderstorms near the center and on its west side. The data revealed the most powerful thunderstorms minus 80 degrees Fahrenheit (minus 62.2 degrees Celsius) near the center. Wind shear was pushing the rest of the storms to the west. Some had cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) and were dropping large amounts of rain. This asymmetric cloud pattern is due to a moderate amount of easterly wind shear.
National Hurricane Center (NHC) intensity forecast follows the trend of the models, and predicts Iselle to weaken to a tropical depression in a couple of days and to a remnant low shortly thereafter.
What Wind Shear Does to a Tropical Cyclone
In general, wind shear is a measure of how the speed and direction of winds change with altitude. Tropical cyclones are like rotating cylinders of winds. Each level needs to be stacked on top each other vertically in order for the storm to maintain strength or intensify. Wind shear occurs when winds at different levels of the atmosphere push against the rotating cylinder of winds, weakening the rotation by pushing it apart at different levels.
Iselle’s Status on Aug. 28, 2020
At 5 a.m. EDT (0900 UTC), the center of Tropical Storm Iselle was located near latitude 17.9 degrees north and longitude 115.0 degrees west. That is about 480 miles (770 km) southwest of the southern tip of Baja California, Mexico. Iselle is moving toward the northeast near 5 mph (7 kph) and this general motion is expected to continue through tonight. Maximum sustained winds have increased to near 60 mph (95 kph) with higher gusts. The estimated minimum central pressure is 997 millibars.
Forecast from NHC
A northward and then northwestward motion is expected during the weekend. Little change in strength is expected today, but a gradual weakening trend should begin tonight.
NASA Researches Earth from Space
For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America’s leadership in space and scientific exploration.
Aug. 27, 2020 – A Nighttime View of Tropical Storm Hernan from a NASA-NOAA Satellite
Nighttime imagery from NASA-NOAA’s Suomi NPP satellite revealed the Eastern Pacific Ocean’s Tropical Storm Hernan along the coast of western Mexico. By the weekend, Hernan is expected to absorb nearby Tropical Storm Iselle.
NASA-NOAA’s Suomi NPP satellite passed the Eastern Pacific Ocean overnight on Aug. 26 at 10 p.m. EDT (Aug. 27 at 0000 UTC) and captured a nighttime image of Tropical Storm Hernan along the western coast of Mexico. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)
Tropical Depression 13E formed by 5 a.m. EDT on Aug. 26 in the Eastern Pacific. Twelve hours later it strengthened to a tropical storm and was renamed Hernan.
NASA’s Night-Time View
The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a nighttime image of Hernan on Aug. 26 at 10 p.m. EDT (Aug. 27 at 0000 UTC).
At 5 a.m. EDT on Aug. 27, the National Hurricane Center noted, “Although Hernan is a sheared tropical cyclone, another strong burst of deep convection with cloud tops of minus 83 to minus 86 degrees Celsius has developed near and south through west of the center.” NASA research has shown that cloud tops that cold have the ability to generate heavy rainfall. By 11 a.m. EDT, first light visible satellite imagery reveals that Hernan remains a sheared tropical cyclone with most of the deep convection confined to the western semicircle.
Hernan’s Status of Aug. 27
At 11 a.m. EDT (1500 UTC) NOAA’s National Hurricane Center noted the center of Tropical Storm Hernan was located near latitude 19.1 degrees north and longitude 106.2 degrees west. That is 95 miles (155 km) southwest of Cabo Corrientes, Mexico. Hernan was moving toward the north-northwest near 5 mph (7 kph). Maximum sustained winds are near 45 mph (75 km/h) with higher gusts. The estimated minimum central pressure is 1001 millibars.
Hernan’s Forecast Track
NHC predicts Hernan will turn to the northwest, along with an increase in forward speed is expected to occur by tonight. A turn to the west is forecast this weekend. On the forecast track, the center of Hernan, along with the strongest winds and heaviest rains, is expected to remain just offshore of the southwestern coast of Mexico. Nearby Tropical Storm Iselle is expected to begin weakening on Friday, and the system is forecast to degenerate into a remnant low-pressure area on Saturday. Iselle’s remnants are expected to be absorbed by the circulation of Hernan to its west on Sunday.
About NASA’s EOSDIS Worldview
NASA’s Earth Observing System Data and Information System (EOSDIS) Worldview application provides the capability to interactively browse over 700 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated within three hours of observation, essentially showing the entire Earth as it looks “right now.”
NASA Researches Earth from Space
For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America’s leadership in space and scientific exploration.
Aug. 27, 2020 – NASA’s Terra Satellite Sees the End of Bavi
NASA’s Terra satellite captured visible imagery as Tropical Storm Bavi made landfall in northwestern North Korea and moved inland.
NASA’s Terra satellite provided a visible image to forecasters of Tropical Storm Bavi after it made landfall in northwestern North Korea on Aug. 27 and began moving into China. Image Courtesy: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).
The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite captured a visible image of Tropical Storm Bavi on Aug. 27. The image showed an almost shapeless tropical storm moving over North Korea and into China.
The final warning from the Joint Typhoon Warning Center was issued at 5 a.m. EDT (0900 UTC) on Aug. 27. At the time, it was located near latitude 41.6 degrees north and longitude 125.8 degrees east, about 249 nautical miles north of Inchon, South Korea. Bavi had weakened to a tropical storm with maximum sustained winds near 40 knots (46 mph/74 kph). It was moving to the north-northeast.
Bavi is quickly becoming extra-tropical after making landfall and is now moving across northeastern China.
When a storm becomes extra-tropical, it means that a tropical cyclone has lost its “tropical” characteristics. The National Hurricane Center defines “extra-tropical” as a transition that implies both poleward displacement (meaning it moves toward the north or south pole) of the cyclone and the conversion of the cyclone’s primary energy source from the release of latent heat of condensation to baroclinic (the temperature contrast between warm and cold air masses) processes. It is important to note that cyclones can become extratropical and still retain winds of hurricane or tropical storm force.
NASA’s Terra satellite is one in a fleet of NASA satellites that provide data for hurricane research.
Tropical cyclones/hurricanes are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.
Aug. 27, 2020 – NASA Finds New Tropical Storm Iselle Already Battling Wind Shear
NASA infrared imagery shows that newly formed Tropical Storm Iselle is already battling for its life under wind shear.
On Aug. 27 at 5:30 a.m. EDT (0930 UTC) the VIIRS instrument that flies aboard NASA-NOAA’s Suomi NPP satellite revealed the most powerful thunderstorms (red) with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) were west of the center and also dropping large amounts of rain. Credit: NASA/NRL
Tropical Depression 14E formed in the Eastern Pacific Ocean on Aug. 26 by 11 a.m. EDT (1500 UTC). By 5 p.m. EDT, it strengthened into a tropical storm and was re-named Iselle.
NASA’s Infrared Data Finds Push of Winds
Tropical cyclones are made up of hundreds of thunderstorms, and infrared data can show where the strongest storms are located. That is because infrared data provides temperature information, and the strongest thunderstorms that reach highest into the atmosphere have the coldest cloud top temperatures. Strongest storms with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) were west of the center and were dropping large amounts of rain.
On Aug. 27 at 5:30 a.m. EDT (0930 UTC), the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite captured a visible image of the structure of Iselle. The storm was elongated and strong storms appeared to be pushed southwest of the center from vertical wind shear.
National Hurricane Center (NHC) Hurricane Specialist Andrew Latto noted in the 11 a.m. EDT discussion, “Iselle consists of a rather ragged looking area of deep convection being sheared to the southwest of a partially exposed low-level center.
Moderate-to-strong easterly to northeasterly vertical wind shear will likely prevent Iselle from strengthening over the next couple of days.
What Wind Shear Does to a Tropical Cyclone
In general, wind shear is a measure of how the speed and direction of winds change with altitude. Tropical cyclones are like rotating cylinders of winds. Each level needs to be stacked on top each other vertically in order for the storm to maintain strength or intensify. Wind shear occurs when winds at different levels of the atmosphere push against the rotating cylinder of winds, weakening the rotation by pushing it apart at different levels.
Iselle’s Status on Aug. 27, 2020
At 11 a.m. EDT (1500 UTC) on Aug. 27, the center of Tropical Storm Iselle was located near latitude 17.0 degrees north and longitude 115.8 degrees west. Iselle is far from land at about 560 miles (900 km) southwest of the southern tip of Baja California, Mexico. Iselle is moving toward the northeast near 5 mph (7 kph), and this motion is expected to continue through Friday. Maximum sustained winds are near 45 mph (75 kph) with higher gusts. The estimated minimum central pressure is 1001 millibars.
Forecast from NHC
Little change in strength is forecast during the next couple of days. Iselle is expected to begin weakening late this weekend.
NASA Researches Earth from Space
For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America’s leadership in space and scientific exploration.
Aug. 27, 2020 – GPM Flies Over Cat. 4 Hurricane Laura Twice As It Makes Landfall in Louisiana
The NASA / JAXA GPM Core Observatory satellite flew over Hurricane Laura shortly before it made landfall at 10:00pm CT on Wednesday, August 26th, then again at 7:42am CT on Thursday, August 27th when it was over land, capturing data on precipitation within the storm.
Hurricane Laura began as a tropical depression on August 21st near the U.S. Virgin Islands, and over the next several days rapidly intensified to a dangerous category 4 hurricane at it moved towards the U.S. Gulf Coast. Laura made landfall as strong category 4 hurricane near Cameron, Louisiana shortly after midnight on August 27, 2020, bringing extreme rainfall, storm surge, and winds up to 150 mph.
The NASA / JAXA GPM Core Observatory satellite flew over Hurricane Laura shortly before it made landfall at 10:00pm CT on Wednesday, August 26th, then again at 7:42am CT on Thursday, August 27th when it was over land, capturing data on precipitation within the storm.
Text by Owen Kelley, Jacob Reed, Joe Munchak (NASA GSFC)
Imagery by Joe Munchak (NASA GSFC)
Aug. 27, 2020 – NASA Sees Hurricane Laura’s Nighttime Landfall
Many NASA assets were used to provide forecasters with information to incorporate into their analysis of Hurricane Laura. Satellite imagery, photographs from the International Space Station, and a computer program that produces animations of imagery are all things that NASA used to analyze the storm. NASA-NOAA’s Suomi NPP satellite also caught a nighttime image of Laura just after landfall.
NASA-NOAA’s Suomi NPP satellite passed over Hurricane Laura soon after it made landfall in southwestern Louisiana around 2 a.m. EDT on Aug. 27 and captured this nighttime image. Laura’s cloud cover extends from Houston, Texas east to just west of New Orleans, Louisiana. Image Courtesy: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).
Laura’s Landfall
Laura made landfall as a powerful Category 4 hurricane along the Louisiana coast. At 2 a.m. EDT (0600 UTC) on Aug. 27, Doppler radar images indicated that the eye of Hurricane Laura made landfall at the coast near Cameron, Louisiana, near latitude 29.8 degrees north and longitude 93.3 degrees west. Air Force reconnaissance and Doppler radar data indicated that the maximum sustained winds were near 150 mph (240 kph) with higher gusts. National Hurricane Center (NHC) Senior Hurricane Specialist John Cangialosi and Hurricane Model Diagnostician and Meteorologist David Zelinsky noted, “At the time of landfall, Laura was a ferocious looking hurricane with a clear circular eye, an intense eyewall, and tightly-coiled surrounding spiral bands.”
A Nighttime View of Laura’s Landfall
NASA-NOAA’s Suomi NPP satellite passed over Hurricane Laura soon after it made landfall in southwestern Louisiana around 2 a.m. EDT on Aug. 27. The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP captured a nighttime image. Laura’s cloud cover extends from Houston, Texas east to just west of New Orleans, Louisiana.
Weather Station Reports Just After Landfall
A National Ocean Service tide station at Calcasieu Pass, Louisiana observed a water level rise of 9.19 feet Mean Higher High Water at 1 a.m. CDT/2 a.m. EDT. The Lake Charles, Louisiana airport reported a sustained wind of 85 mph (137 kph) with a gust to 128 mph (206 kph) around 2 a.m. CDT/3 a.m. EDT. A University of Florida observing tower near Lake Charles recently reported a sustained wind of 86 mph (138 kph) with a gust to 112 mph (180 kph). A Texas Coastal Ocean Observing Network site at Sabine Pass on the Texas/Louisiana border reported sustained winds of 74 mph (119 kph) with a gust to 90 mph (145 kph).
Watches and Warnings on Aug. 27, 2020
A Storm Surge Warning is in effect for High Island, Texas to the mouth of the Mississippi River.
A Tropical Storm Warning is in effect for High Island, Texas to the mouth of the Mississippi River.
Animating Hurricane Laura’s Path to Landfall
This animation of visible imagery from NASA-NOAA’s Suomi NPP satellite from Aug. 20 to 26 shows Tropical Storm Marco move from the Caribbean Sea to a landfall near the mouth of the Mississippi, as Tropical Storm Laura moves from the east, over Puerto Rico, Hispaniola and into the Gulf of Mexico, just before landfall in southwestern Louisiana. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)
The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a visible imagery of Laura from its birth in the Atlantic. Using the Worldview application at NASA’s Goddard Space Flight Center in Greenbelt, Md., an animation was created of Laura’s track from Puerto Rico to Louisiana. The imagery spanned from Aug. 20 to 26 and showed Tropical Storm Marco move from the Caribbean Sea to a landfall near the mouth of the Mississippi while Tropical Storm Laura moved from the east over Puerto Rico, Hispaniola and into the Gulf of Mexico, just before landfall in southwestern Louisiana.
NASA’s Earth Observing System Data and Information System (EOSDIS) Worldview application provides the capability to interactively browse over 700 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated within three hours of observation, essentially showing the entire Earth as it looks “right now.”
A View from the International Space Station
Astronaut Chris Cassidy aboard the International Space Station took several photos of Hurricane Laura as it neared the Gulf coast on Aug. 26, 2020 at 3:27 p.m. EDT. The photos showed the extent of this large hurricane. The photos also revealed a clear eye surrounded by powerful thunderstorms. The photo below is one of four taken by Cassidy from the ISS.
From the International Space Station Astronaut Chris Cassidy took this photo of Hurricane Laura as it neared the Gulf coast on Aug. 26, 2020 at 3:27 p.m. EDT. Credit: NASA/Chris Cassidy
Laura’s Status on Aug. 27 at 8 a.m. EDT
At 8 a.m. EDT (1200 UTC), the center of Hurricane Laura was located near latitude 31.2 degrees north and longitude 93.3 degrees west. That is about 20 miles (30 km) north of Fort Polk, Louisiana.
Laura is moving toward the north near 15 mph (24 kph) and this motion should continue through the day. A northeastward to east-northeastward motion is expected tonight and Friday. Maximum sustained winds are near 100 mph (160 kph) with higher gusts. Laura is now a Category 2 hurricane on the Saffir-Simpson scale at present based on wind speed.
Hurricane-force winds extend outward up to 60 miles (95 km) from the center and tropical-storm-force winds extend outward up to 175 miles (280 km). An observing site in Alexandria, Louisiana, recently reported a wind gust to 74 mph (119 kph).The estimated minimum central pressure is 970 millibars.
Laura’s Forecast and Track
NHC warned about dangerous storm surge, heavy rainfall, hurricane-force winds and isolated tornadoes.
NHC said, “The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide.
Through Friday, forecasters expect Laura to produce the following rainfall totals: Across portions of Louisiana, Mississippi, across Arkansas: 6 to 12 inches with isolated totals of 18 inches. This rainfall will cause widespread flash and urban flooding, small streams and creeks to overflow their banks, and minor to moderate freshwater river flooding.
Hurricane-force winds and damaging wind gusts are also expected to spread well inland into portions of eastern Texas and western Louisiana this morning. Tropical storm conditions will spread northward within the warning areas through the day.
In addition, tornadoes are possible today and tonight over parts of Louisiana, Arkansas, and western Mississippi.”
Rapid weakening is forecast, and Laura is expected to become a tropical storm later today (Aug. 27). On the forecast track, Laura will move northward across western and northern Louisiana through this afternoon. The center of Laura is forecast to move over Arkansas tonight, the mid-Mississippi Valley on Friday, and the Mid-Atlantic States on Saturday.
NASA Researches Tropical Cyclones
Hurricanes/tropical cyclones are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.
For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America’s leadership in space and scientific exploration.
Aug. 26, 2020 – Update #2 – NASA Examines Powerful Major Hurricane Laura Headed for Landfall
During the afternoon of Aug. 26, as major Hurricane Laura nears landfall near the Texas/Louisiana border, NASA satellites have been providing forecasters with a great deal of data on the storm, examining temperature, rainfall capability, storm structure and extent.
NASA’s Terra satellite provided a visible image of the large and powerful major Hurricane Laura in the Gulf of Mexico on Aug. 26, 2020 at 2:30 p.m. EDT. Laura’s eye was clearly visible, the storm was well rounded, and the eye was surrounded by powerful thunderstorms. Credit: NASA Worldview
Infrared Data Reveals Powerful Rainmaking Capabilities
On Aug. 25 at 11:35 p.m. EDT (Aug. 26 at 0335 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite revealed the most powerful thunderstorms were around Laura’s center where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). Strong storms with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) surrounded the center and were generating large amounts of rain. NASA research has determined that cloud top temperatures as cold as or colder than minus 63 degrees Fahrenheit (minus 52.7 degrees Celsius) has the capability to generate heavy rainfall.
NASA’s Visible Image Of Cat 4 Hurricane Laura on Aug. 26
The MODIS instrument aboard NASA’s Terra satellite provided a visible image of the large and powerful major Hurricane Laura in the Gulf of Mexico on Aug. 26, 2020 at 2:30 p.m. EDT. Laura’s eye was clearly visible, the storm was well rounded, and the eye was surrounded by powerful thunderstorms.
Watches and Warnings on Aug. 25
On Aug. 25, NOAA’s National Hurricane Center (NHC) posted several watches and warnings on major Hurricane Laura.
A Storm Surge Warning is in effect for San Luis Pass, Texas to the mouth of the Mississippi River. A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline, during the next 36 hours in the indicated locations. Some of the storm surge forecasts are extreme. Johnson Bayou, LA to Rockefeller Wildlife Refuge including Calcasieu Lake is between 15 to 20 feet. Sea Rim State Park, TX to Johnson Bayou, LA including Sabine Lake is between 10 and 15 feet. Rockefeller Wildlife Refuge to Intracoastal City, LA between 10 and 15 feet. Intracoastal City, LA to Morgan City including Vermilion Bay between 8 to 12 feet. For additional areas and storm surges, visit: www.nhc.noaa.gov.
A Hurricane Warning is in effect from San Luis Pass, Texas to Intracoastal City, Louisiana.
A Tropical Storm Warning is in effect from Sargent, Texas to San Luis Pass and for areas east of Intracoastal City, Louisiana to the mouth of the Mississippi River.
A Storm Surge Watch is in effect for Freeport, Texas to San Luis Pass, Texas, the mouth of the Mississippi River to Ocean Springs, Mississippi, and for Lake Pontchartrain, Lake Maurepas, and Lake Borgne.
A Hurricane Watch is in effect for from east of Intracoastal City to west of Morgan City, Louisiana.
On Aug. 25 at 11:35 p.m. EDT (Aug. 26 at 0335 UTC) the MODIS instrument that flies aboard NASA’s Aqua satellite revealed the most powerful thunderstorms (yellow) were around Laura’s center where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). Strong storms (red) with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) surrounded the center and were generating large amounts of rain. Credit: NASA/NRL
Laura’s Status on Aug. 26, 2020 at 2 p.m. EDT
NOAA’s National Hurricane Center (NHC) reported at 2 p.m. EDT (1800 UTC), the eye of Hurricane Laura was located near latitude 27.3 degrees north and longitude 92.5 degrees west. That is about 200 miles (20 km) south-southeast of Lake Charles, Louisiana.
Laura is moving toward the northwest near 16 mph (26 kph). A gradual turn toward the north-northwest and north is expected later today and tonight. Reports from an Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds have increased to near 140 mph (220 kph) with higher gusts. Laura is an extremely dangerous category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some additional strengthening is possible this afternoon, and Laura is forecast to remain a category 4 hurricane through landfall tonight. Rapid weakening is expected after Laura makes over land.
Hurricane-force winds extend outward up to 70 miles (110 km) from the center and tropical-storm-force winds extend outward up to 175 miles (280 km). Tropical-storm-force winds have reached the coast of Louisiana and an observing site at Eugene Island recently measured sustained winds of 39 mph (63 kph) and a gust to 64 mph (104 kph).
The latest minimum central pressure estimated from reconnaissance aircraft data is 952 millibars.
Laura’s Forecast from NHC
The NHC warns that Laura will likely make landfall as a Category 4 hurricane and bring devastating effects. Heavy rain, dangerous storm surge, isolated tornadoes and hurricane-force sustained winds are expected. On the forecast track, Laura will approach the Upper Texas and southwest Louisiana coasts this evening and move inland within that area tonight. The center of Laura is forecast to move over northwestern Louisiana tomorrow, across Arkansas Thursday night, and over the mid-Mississippi Valley on Friday.
NASA Researches Earth from Space
For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America’s leadership in space and scientific exploration.
