September 2020 – Page 6 – Hurricane And Typhoon Updates

Rene – Atlantic Ocean

Sep. 14, 2020 – NASA’s Aqua Satellite Finds Rene Barely a Depression Battered by Wind Shear

Tropical Depression Rene continues to be the victim of strong wind shear and forecasters anticipate it will lead to the storm’s demise in the next couple of days. NASA’s Aqua satellite viewed the storm in infrared light to find wind shear was pushing Rene’s strongest storms away from the center, preventing the storm from re-organizing and strengthening.

Aqua image of Rene — On Sept. 15 at 1:05 a.m. EDT (0505 UTC), the MODIS instrument that flies aboard NASA’s Aqua satellite gathered infrared data on Rene that confirmed wind shear was adversely affecting the storm. Persistent north-northeasterly vertical wind shear showed strongest storms (red) pushed to the east-southeast of the center where cloud top temperatures were as cold as minus 70 degrees Fahrenheit (minus 56.6 Celsius). Credit: NASA/NRL

NASA’s Aqua Satellite Reveals Effects of Wind Shear

On instrument aboard NASA’s Aqua satellite uses infrared light to analyze cloud top temperatures in a tropical cyclone’s clouds to determine strength. The strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures.

On Sept. 15 at 1:05 a.m. EDT (0505 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite gathered infrared data on Rene that confirmed wind shear was adversely affecting the storm. Persistent north-northeasterly vertical wind shear showed strongest storms (red) pushed to the east-southeast of the center where cloud top temperatures were as cold as minus 70 degrees Fahrenheit (minus 56.6 Celsius).

National Hurricane Center forecaster Jack Beven noted, “Rene continues to produce just enough deep convection to keep it from degenerating to a remnant low. However, it is expected to degenerate later today due to the ongoing impact of strong west-northwesterly vertical shear and dry air entrainment.”

Wind Shear Affecting Rene

The shape of a tropical cyclone provides forecasters with an idea of its organization and strength. When outside winds batter a storm, it can change the storm’s shape and push much of the associated clouds and rain to one side of it. That is what wind shear does.

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.

Status of Tropical Depression Rene

At 5 a.m. EDT (0900 UTC), the center of Tropical Depression Rene was located near latitude 27.4 degrees north and longitude 48.3 degrees west. Rene is centered about 1,115 miles (1,795 km) northeast of the Leeward Islands. The depression is moving toward the west near 3 mph (6 km/h). Maximum sustained winds are near 30 mph (45 kph) with higher gusts. The estimated minimum central pressure is 1011 millibars.

Rene’s Forecast

A faster motion toward the west-southwest or southwest is forecast to begin later today, Sept. 14 and continue through dissipation. Weakening is forecast, and Rene is expected to become a remnant low later today and dissipate by Wednesday, Sept. 16.

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.

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

By Rob Gutro
NASA’s Goddard Space Flight Center

Paulette – Atlantic Ocean

Sep. 14, 2020 – NASA Night-time Image Shows Hurricane Paulette’s Large Eye Approach Bermuda

Night-time imagery from NASA-NOAA’s Suomi NPP satellite showed Hurricane Paulette’s large eye approaching the island of Bermuda. A Hurricane Warning is in effect for Bermuda.

Suomi NPP image of Paulette — NASA-NOAA’s Suomi NPP satellite passed the Atlantic Ocean at 1:30 a.m. EDT (0530 UTC) and captured a night-time image of Hurricane Paulette as its 35- to 40-mile-wide-eye approached Bermuda. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)

Bermuda is a British territory in the western Atlantic Ocean. It is located approximately 643 miles (1,035 km) east-southeast of Cape Hatteras, North Carolina.

NASA’s Night-Time View of Elida’s Intensification

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a nighttime image of Hurricane Paulette at 1:30 a.m. EDT (0530 UTC). The large eye, between 35 and 40 miles in diameter, was clearly apparent in the nighttime image, and it was surrounded by powerful thunderstorms. Hurricane-force winds extend outward up to 45 miles (75 km) from the center and tropical-storm-force winds extend outward up to 175 miles (280 km).

The image was created using the NASA Worldview application at NASA’s Goddard Space Flight Center in Greenbelt, Md.

Hurricane Paulette’s Status

At 5 a.m. EDT on Sept. 14, the eye of Paulette circled the entire island of Bermuda. The center of the eye of Hurricane Paulette was located over northeastern Bermuda or near latitude 32.3 degrees north and longitude 64.7 degrees west.

NOAA’s National Hurricane Center (NHC) said Paulette is moving toward the north-northwest near 12 mph (19 km/h), and this motion should continue early this morning. A turn toward the north is expected by late morning and will continue into this afternoon. A faster motion toward the northeast is expected by this evening and will continue through Wednesday.

Maximum sustained winds have increased to near 90 mph (150 km/h) with higher gusts. Additional strengthening is likely when Paulette turns northeastward and moves away from Bermuda tonight through Tuesday. Although winds have subsided across much of Bermuda due to Paulette’s eye passage, hurricane-force winds will return shortly when the southern portion of Paulette’s eyewall passes over the island. Tropical-storm-force winds will continue possibly into the early afternoon across the entire island. The estimated minimum central pressure based on surface observations on Bermuda is 973 millibars.

Paulette’s Forecast Track

At 5 a.m. EDT, the NHC noted that on the forecast track, the eye of Paulette will continue to pass over Bermuda during the next couple of hours, followed by passage of the southern portion of the eyewall.

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

By Rob Gutro
NASA’s Goddard Space Flight Center

Sally – Atlantic Ocean

Sep. 13, 2020 – NASA Satellite Confirms Tropical Storm Sally Strengthening, Threatens Gulf States

NASA’s Terra satellite passed over the Gulf of Mexico on Saturday, Sept. 12 and visible imagery helped confirm that the nineteenth tropical cyclone of the Atlantic Ocean hurricane season strengthened into a tropical storm.

On Sept. 12 at 1:30 p.m. EDT, NASA’s Terra satellite captured a visible image as it passed over newly developed Tropical Storm Sally between southern Florida and Cuba. Credit: NASA Worldview

Tropical Depression 19 formed late on Friday, Sept. 11, and by 2 p.m. EDT on Saturday, Sept. 12, it had strengthened into a tropical storm and was renamed Sally. Visible imagery from NASA’s Terra satellite helped confirm the organization of the storm.

On Sept. 12, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard Terra provided a visible image newly developed tropical cyclone. The imagery showed better-defined banding features over the southern portion of the circulation than earlier in the day. Sally appeared more organized on satellite imagery, enough to be classified as a tropical storm.

As Sally strengthened and moved away from the Florida Peninsula during the morning hours of Sept. 13, the National Hurricane Center (NHC) posted many warnings and watches along the northern Gulf coast.

Warnings and Watches on Sept. 13

A Storm Surge Warning is in effect for Port Fourchon, Louisiana to the Mississippi/Alabama Border and for Lake Pontchartrain, Lake Maurepas, and Lake Borgne. A Hurricane Warning is in effect for Morgan City, Louisiana to Ocean Springs, Mississippi and for Lake Pontchartrain and Lake Maurepas including metropolitan New Orleans. A Tropical Storm Warning is in effect for east of Ocean Springs to Indian Pass and from Intracoastal City, Louisiana to west of Morgan City.

A Storm Surge Watch is in effect for the Mississippi/Alabama Border to the Alabama/Florida Border. A Hurricane Watch is in effect for east of Ocean Springs to the Alabama/Florida Border. A Tropical Storm Watch is in effect for Indian Pass to Ochlockonee River, Florida.

Sally’s Status on Sept. 13, 2020

At 11 a.m. EDT (1500 UTC), NHC reported the center of Tropical Storm Sally was located near latitude 27.5 degrees north and longitude 84.9 degrees west. That is about 135 miles (225 km) west of St. Petersburg, Florida.

Sally is moving toward the west-northwest near 12 mph (19 km/h), and a west-northwestward or northwestward motion is expected through Monday. Data from an Air Force Reserve Hurricane Hunter aircraft indicate that the maximum sustained winds have increased to near 60 mph (95 kph) with higher gusts. Strengthening is expected over the next day or so, and Sally is forecast to become a hurricane on Monday with some additional strengthening possible before landfall Monday night.

Sally’s Forecast Track

A decrease in forward speed and a turn toward the north-northwest is forecast on Monday night, and slow north-northwestward motion is expected Tuesday. On the forecast track, the center of Sally will move over the eastern Gulf of Mexico today, move over the north-central Gulf of Mexico tonight and Monday, and approach the north-central Gulf Coast within the hurricane warning area late Monday and Monday night. Sally is expected to move farther inland over southeastern Louisiana on Tuesday and Tuesday night.

For updated forecasts. Visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Paulette – Atlantic Ocean

Sep. 11, 2020 – NASA Satellite Finds a Wedge-Shaped Tropical Storm Paulette

Wind shear was affecting both Tropical Storm Paulette and Rene in the Atlantic Ocean on Sept. 11. Infrared imagery from NASA’s Aqua satellite showed that strong southwesterly wind shear pushed against Paulette creating a wedge-shaped storm.

Aqua image of Paulette — On Sept. 11 at 12:35 a.m. EDT (0435 UTC), the MODIS instrument that flies aboard NASA’s Aqua satellite revealed a small area of the most powerful thunderstorms (yellow) around Paulette’s center where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). A larger area of 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

Wind Shear Affecting Paulette

Tropical cyclones that appear less than round are likely being affected by wind shear or outside winds transitioning into an extra-tropical cyclone or taking on the elongated appearance of a weather front. Today, Sept. 11, wind shear has given Paulette a wedge-shape.

The shape of a tropical cyclone provides forecasters with an idea of its organization and strength. When outside winds batter a storm, it can change the storm’s shape. Winds can push most of the associated clouds and rain to one side of a storm.

At 5 a.m. EDT (0900 UTC) on Sept. 11, “Paulette continues to experience the effects of 35 to 40 knots of southwesterly vertical shear, which has caused the center to occasionally become exposed to the south and southwest of the primary convective bursts,” noted Jack Beven, Senior Hurricane Specialist at NOAA’s National Hurricane Center in Miami, Fla.

Infrared Data Reveals Effects of Wind Shear

NASA’s Aqua satellite uses infrared light to analyze the strength of storms by providing temperature information about the system’s clouds. The strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures.

On Sept. 11 at 12:35 a.m. EDT (0435 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite revealed a very small area of Paulette’s most powerful thunderstorms around its center where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). A larger area of strong storms with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) surrounded the center. NASA research has found that storms with cloud tops as cold as at least minus 70 degrees Fahrenheit can generate heavy rain.

At 5 a.m. EDT on Sept. 11, NHC noted that the wind shear Paulette is currently experiencing should subside. However, it may be another 24 hours before it subsides enough so that significant strengthening can occur.

Paulette’s Status on Sept. 11

At 5 a.m. EDT (0900 UTC), the center of Tropical Storm Paulette was located near latitude 23.1 degrees north and longitude 51.7 degrees west. That is about 810 miles (1,305 km) east-northeast of the Northern Leeward Islands. Paulette is moving toward the west-northwest near 10 mph (17 kph). Maximum sustained winds are near 65 mph (100 kph) with higher gusts. Little change in strength is expected today. The estimated minimum central pressure is 991 millibars.

Paulette’s Weekend Forecast

NHC forecasters expect a motion toward the northwest for the next few days. On the forecast track, the center of Paulette should approach Bermuda Sunday night and Monday. Gradual strengthening is expected to begin tonight or on Saturday, and Paulette is forecast to become a hurricane this weekend.

Ocean Swells Expected from Paulette

Swells generated by Paulette are expected to reach portions of the Leeward Islands today and will continue to spread westward to portions of the Greater Antilles, Bahamas, Bermuda, and the southeastern United States into the weekend. These swells are likely to cause life-threatening surf and rip current conditions.

NASA Researches Earth from Space

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

By Rob Gutro
NASA’s Goddard Space Flight Center

Rene – Atlantic Ocean

Sep. 11, 2020 – NASA Satellite Finds an Elongated Tropical Storm Rene Caused by Wind Shear

Infrared imagery from NASA’s Aqua satellite showed an elongated Tropical Storm Rene being battered by wind shear in the Central Atlantic Ocean. Tropical cyclones that appear less than round are likely being affected by wind shear or outside winds transitioning into an extra-tropical cyclone or taking on the elongated appearance of a weather front. Outside winds have given Rene’s strongest storms an appearance like that of a triangle.

Wind Shear Affecting Rene

Infrared Data Reveals Effects of Wind Shear

On Sept. 11 at 12:35 a.m. EDT (0435 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite revealed a small area of Rene’s most powerful thunderstorms around its center where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). A larger area of strong storms with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) surrounded the center in what looks like a triangular shape. NASA research has found that storms with cloud tops as cold as at least minus 70 degrees Fahrenheit can generate heavy rain.

At 5 a.m. EDT on Sept. 11, U.S. Navy Hurricane Specialist, Dave Roberts of NOAA’s National Hurricane Center in Miami, Fla. noted in the Rene discussion, “A microwave pass revealed that Rene’s surface center is farther separated from the shrinking deep convection. Model soundings indicate that east-southeasterly 30 to 25 knot [vertical wind] shear near 300 millibars is temporarily undercutting the diffluent southerly flow aloft.” An air pressure of 300 millibars is about 30,000 feet (9,100 meters) high in the atmosphere, but it can vary between 27,000 to 32,000 feet (8,200 to 9,600 meters).

The wind shear Rene is currently experiencing is expected to relax during the next 36 to 48 hours (from 5 a.m. EDT on Sept. 11) which should allow for gradual intensification. “By mid-period, Rene is forecast to move into an area of increasing west-northwesterly shear, which should induce a weakening trend,” Roberts noted.

Rene’s Status on Sept. 11

At 5 a.m. EDT (0900 UTC), the center of Tropical Storm Rene was located near latitude 19.7 degrees north and longitude 38.5 degrees west. Rene is 985 miles (1,585 km) west-northwest of the Cabo Verde Islands. Rene is moving toward the west-northwest near 10 mph (17 kph). This general motion is expected to continue through Friday night, followed by a turn toward the northwest on Saturday. Maximum sustained winds are near 45 mph (75 kph) with higher gusts. The estimated minimum central pressure is 1002 millibars.

Rene’s Weekend Forecast

NHC forecasters expect a north-northwestward and northward motion with a decrease in forward speed on Sunday and Sunday night [Sept. 13]. Gradual strengthening is forecast during the couple of days. Afterward, weakening is expected to begin by Sunday night.

NASA Researches Earth from Space

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

By Rob Gutro
NASA’s Goddard Space Flight Center

Rene – Atlantic Ocean

Sep. 10, 2020 – NASA Finds Tropical Storm Rene Less Affected by Wind Shear

NASA’s Terra satellite obtained visible imagery of Tropical Storm Rene is it continued moving north though the central North Atlantic Ocean. Rene appeared more organized on satellite imagery as wind shear eased.

Terra image of Rene — On Sept. 10, 2020, NASA’s Terra satellite provided a visible image of Tropical Storm Rene, and the eastern side of Tropical Storm Paulette (top left) moving through the Atlantic Ocean. Image Courtesy: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).

NASA Satellite View: Rene’s Organization

The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite captured a visible image of Tropical Storm Rene on Sept. 10. Rene appeared slightly more circular. That is because vertical wind shear (outside winds blowing at different levels of the atmosphere) appears to have lessened somewhat over Rene allowing the storm to organize. The image showed Tropical Storm Paulette was located to Rene’s northwest.

Satellite imagery was created using NASA’s Worldview product at NASA’s Goddard Space Flight Center in Greenbelt, Md.

Rene on Sept. 10

At 11 a.m. EDT (1500 UTC) on Sept. 10, the center of Tropical Storm Rene was located near latitude 18.6 degrees north and longitude 35.8 degrees west. Rene was about 800 miles (1,285 km) west-northwest of the Cabo Verde Islands.

Rene is moving toward the west-northwest near 12 mph (19 kph). This general motion is expected to continue for the next couple of days, followed by a turn toward the northwest. Maximum sustained winds have increased to near 50 mph (85 kph) with higher gusts. The estimated minimum central pressure is 1000 millibars.

NOAA’s National Hurricane Center (NHC) noted that additional strengthening is forecast for the next couple of days as vertical wind shear is not expected to be strong. Therefore, Rene is expected to become a hurricane by Saturday, Sept. 12. The storm is not expected to affect any land areas in the next five days, according to the NHC forecast.

About NASA’s Worldview and Terra Satellite

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.

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

By Rob Gutro
NASA’s Goddard Space Flight Center

Paulette – Atlantic Ocean

Sep. 10, 2020 – Infrared NASA Imagery Provides Paulette’s Temperature Palette

NASA’s Aqua satellite analyzed Tropical Storm Paulette in infrared imagery as it moved through the Central Atlantic Ocean. At NASA, the imagery was false-colored to show cloud-top temperature gradients and identify the locations of the strongest storms. The imagery also indicated Paulette was being affected by wind shear.

AIRS image of Paulette — On Sept. 9 at 12:47a.m. EDT (0447 UTC) NASA’s Aqua satellite analyzed Tropical Storm Paulette using the Atmospheric Infrared Sounder or AIRS instrument. AIRS found coldest cloud top temperatures as cold as or colder than (purple) minus 63 degrees Fahrenheit (minus 53 degrees Celsius) northeast of the center and in a band of thunderstorms south of center. Credit: NASA JPL/Heidar Thrastarson

Infrared Imagery and Paulette’s Strength

One of the ways NASA researches tropical cyclones is using infrared data that provides temperature information. The AIRS instrument aboard NASA’s Aqua satellite captured a look at those temperatures in Paulette and gave insight into the size of the storm and its rainfall potential.

Cloud top temperatures provide information to forecasters about where the strongest storms are located within a tropical cyclone. Tropical cyclones do not always have uniform strength, and some sides have stronger sides than others. The stronger the storms, the higher they extend into the troposphere, and the colder the cloud top temperatures. NASA provides that data to forecasters at NOAA’s National Hurricane Center or NHC so they can incorporate in their forecasting.

On Sept. 9 at 12:47 a.m. EDT (0447 UTC) NASA’s Aqua satellite analyzed Tropical Storm Paulette using the Atmospheric Infrared Sounder or AIRS instrument. AIRS found coldest cloud top temperatures as cold as or colder than minus 63 degrees Fahrenheit (minus 53 degrees Celsius) northeast of the center and in a band of thunderstorms south of center. The center is near the southern side of a large thunderstorm cluster, with the bulk of deep convection in the northeastern quadrant of the cyclone.

NASA research has shown that cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain.

Paulette had maximum sustained winds near 60 mph (95 kph) at the time of the AIRS image. Wind shear continued to affect the storm and weakened it over the next day.

What is Wind Shear?

Paulette’s Status of Sept. 10

By 5 a.m. EDT (0900 UTC) on Sept. 10, although Paulette’s center of circulation had separated farther south from the cloud mass during the early morning hours, infrared imagery showed the cyclone was still producing an area of deep convection and strong thunderstorms consisting of minus 79 degrees Celsius (minus 110.2 degrees Fahrenheit) cold cloud tops.

Robbie Berg, hurricane specialist at NOAA’s National Hurricane Center in Miami, Florida, noted at 11 a.m. EDT on Sept. 10, “Southwesterly shear has increased over the cyclone as expected, with the latest University of Wisconsin-Madison-CIMSS analysis now between 35 and 40 knots.” The wind shear is expected to peak by 11 p.m. EDT on Sept. 10, so a little more weakening is anticipated over the next day or so. The shear is then forecast to gradually abate.

At 11 a.m. EDT (1500 UTC), NHC reported the center of Tropical Storm Paulette was located near latitude 21.5 degrees north and longitude 49.1 degrees west. That is about 935 miles (1,510 km) east-northeast of the Northern Leeward Islands. Paulette is moving toward the west-northwest near 10 mph (17 kph). A west-northwestward or northwestward motion with some increase in forward speed is expected through the weekend. Maximum sustained winds have decreased to near 50 mph (85 kph) with higher gusts.

Paulette’s Forecast

NHC expects a west-northwestward or northwestward motion with some increase in forward speed through the weekend. Some additional slight weakening is expected during the next day or so, but Paulette is then forecast to re-strengthen by Saturday. Paulette could become a hurricane by Sunday or Monday.

There are no coastal watches or warnings in effect. Interests in Bermuda should monitor the progress of this system. Ocean swells forecast to spread across the southwestern Atlantic through the weekend.

The AIRS instrument is one of six instruments flying on board NASA’s Aqua satellite, launched on May 4, 2002.

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

By Rob Gutro
NASA’s Goddard Space Flight Center

Rene – Atlantic Ocean

Sep. 09, 2020 – NASA Infrared Imagery Shows Tropical Storm Rene’s Seesaw of Strength

Tropical Storm Rene weakened to a tropical depression late on Sept. 8 but regained tropical storm status on Sept. 9. Infrared imagery from NASA’s Aqua satellite captured Rene as it was twice transitioning.

Rene has been battling wind shear in the eastern North Atlantic Ocean and when NASA’s Aqua satellite passed over the storm on Sept. 8, it found Rene weakening although still a tropical storm. Wind shear occurs when winds blowing outside of a tropical cyclone at different levels of the atmosphere push against the tropical cyclone and weaken it.

NASA’s Infrared Views of Rene

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.

AIRS image of Rene — On Sept. 8 at 10:59 a.m. EDT (1459 UTC), NASA’s Aqua satellite analyzed Rene’s cloud top temperatures. Imagery showed the strongest storms (purple) east of the center of circulation, and in fragmented bands west of the center where coldest cloud top temperatures as cold as or colder 210 Kelvin minus 81 degrees Fahrenheit (minus 63.1 degrees Celsius). Credit: NASA JPL/Heidar Thrastarson

On Sept. 8 at 10:59 a.m. EDT (1459 UTC), NASA’s Aqua satellite analyzed the storm using the Atmospheric Infrared Sounder or AIRS instrument. The AIRS imagery showed the strongest storms east of the center of circulation, and in fragmented bands west of the center where coldest cloud top temperatures as cold as or colder 210 Kelvin minus 81 degrees Fahrenheit (minus 63.1 degrees Celsius). NASA research has shown that cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain.

By 11 p.m. EDT on Sept. 8, although Rene had weakened to a tropical depression, infrared imagery revealed a burst of strong convection with cloud tops colder than minus 80 degrees Celsius (minus 112 Fahrenheit) had developed over and to the west of the center, while a fragmented band of convection had formed in the northern semicircle.

On Sept. 8 at 11:15 p.m. EDT (Sept. 9 at 0315 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite used infrared light to analyze the strength of storms within Rene. MODIS showed that burst of convection and showed the most powerful thunderstorms had cloud top temperatures were as cold as or colder than 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 that area. NASA research has found that cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

Rene’s outflow was symmetrical in all quadrants, but because scatterometer data showed that its winds dropped to 30 knots (35 mph/56 kph) per hour, it was classified as a tropical depression. Less than six hours later, infrared imagery showed Rene was becoming better organized and in an additional six hours, it would regain its strength.

On Sept. 9 at 11 a.m. EDT, Richard Pasch, Senior Hurricane Specialist at NOAA’s National Hurricane Center in Miami, Fla. noted, “Although easterly wind shear has been affecting the system, Rene is producing vigorous deep convection, along with a broad convective band, over its western semicircle. Scatterometer data indicate winds to 35 knots [40 mph/65 kph] over the northwestern quadrant, and therefore the system is again being designated as a tropical storm.”

Rene’s Status on Sept. 9

At 11 a.m. EDT (1500 UTC) on Sept. 9, Rene re-strengthened into a tropical storm. At that time, the center of Tropical Storm Rene was located near latitude 17.6 degrees north and longitude 31.5 degrees west. Rene is moving toward the west-northwest near 13 mph (20 kph). The estimated minimum central pressure is 1003 millibars. Satellite-derived wind data indicate that the maximum sustained winds have increased to near 40 mph (65 kph) with higher gusts.

Rene’s Forecast from NHC

The NHC forecasts additional strengthening during the next 48 hours and a motion toward the west-northwest is expected for the next couple of days, followed by a turn to the northwest.

NASA Researches Earth from Space

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

By Rob Gutro
NASA’s Goddard Space Flight Center

Paulette – Atlantic Ocean

Sep. 09, 2020 – NASA Infrared Imagery Shows Wind Shear Affecting Tropical Storm Paulette

Tropical Storm Paulette has run into wind shear that is pushing the bulk of clouds and showers away from its center of circulation, and that is apparent on infrared imagery from NASA.

A large upper-level trough or elongated area of low pressure is located to the northwest of Paulette, and this feature is producing 20 to 30 knots (23 to 35 mph/37 to 56 kph) of south-southwesterly wind shear over the cyclone. Wind shear occurs when winds blowing outside of a tropical cyclone at different levels of the atmosphere push against the tropical cyclone weakening it. The wind shear Paulette is experiencing is pushing the bulk of clouds to the north-northeast of the center.

NASA’s Infrared Data Reveals Heavy Rainmakers

On Sept. 9 at 12:50 a.m. EDT (0450 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite used infrared light to analyze the strength of storms within Paulette. MODIS found the most powerful thunderstorms were near Paulette’s center where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). However, strong storms with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) were being pushed east-northeast of those most powerful storms. NASA research has found that cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

Hurricane Specialist Robbie Berg of NOAA’s National Hurricane Center in Miami, Fla. noted, “Morning visible satellite images show that Paulette’s center is located beneath a thin veil of cirrus clouds and displaced to the south of the deep convection.”

Paulette’s Status on Sept. 9

At 11 a.m. EDT (1500 UTC) on Sept. 9, the center of Tropical Storm Paulette was located near latitude 20.0 degrees north and longitude 46.5 degrees west. Paulette is 1,090 miles (1,755 km) east of the Northern Leeward Islands. Paulette is moving toward the west-northwest near 9 mph (15 kph). Maximum sustained winds are near 60 mph (95 kph) with higher gusts. The estimated minimum central pressure is 996 millibars.

Paulette’s Forecast from NHC

The NHC forecasts a general westward or west-northwestward motion through Friday, followed by a turn toward the northwest Friday night and Saturday. Some weakening is forecast during the next couple of days.

NHC said, “Swells generated by Paulette are expected to reach portions of the Leeward Islands Thursday night and Friday and will continue to spread westward to portions of the Greater Antilles, Bahamas, and Bermuda into the weekend. These swells are likely to cause life-threatening surf and rip current conditions.”

NASA Researches Earth from Space

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

By Rob Gutro
NASA’s Goddard Space Flight Center

Paulette – Atlantic Ocean

Sep. 08, 2020 – NASA-NOAA Satellite Tracking Record-Breaking Tropical Storm Paulette

NASA-NOAA’s Suomi NPP satellite provided forecasters with a visible image of Tropical Storm Paulette as it tracked through the Central North Atlantic Ocean on Sept. 8. Paulette, like some other tropical storms this year, has broken a season record.

Tropical Depression 17 developed on Sunday, Sept. 6 by 11 p.m. EDT about 1,160 miles (1,865 km) west of the Cabo Verde Islands. Twelve hours later on Sept. 7 at 11 a.m. EDT, it had strengthened and organized into a tropical storm and was renamed Tropical Storm Paulette.

Record-Breaking Paulette

Paulette’s development set another hurricane season record. Paulette is the 16th named storm of the 2020 Atlantic hurricane season. It is also the earliest 16th named storm of any Atlantic season by 10 days. The previous record was Philippe, which formed on September 17, 2005.

Satellite Views of Paulette

On Sept. 8, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a visible image of Paulette when it passed overhead. Forecasters looking at the VIIRS imagery noted that Paulette’s organization had noticeably improved since last night. The tropical storm is still sheared (vertical wind shear is pushing against the storm from the northeast), with its outflow restricted to the southwest.

The National Hurricane Center noted, “Overnight AMSU imagery indicated that convection was beginning to wrap around the western portion of its circulation.” The Advanced Microwave Sounding Unit (AMSU) is a multi-channel microwave radiometer installed on meteorological satellites. The instrument examines several bands of microwave radiation from the atmosphere to perform atmospheric sounding of temperature and moisture levels. That instrument flies aboard NASA’s Aqua satellite and NOAA weather satellites.

On Sept. 8 at 12:05 a.m. EDT (0405 UTC) NASA’s Aqua satellite analyzed Paulette using the Atmospheric Infrared Sounder or AIRS instrument. AIRS found coldest cloud top temperatures as cold as or colder than minus 63 degrees Fahrenheit (minus 53 degrees Celsius). NASA research has shown that cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain.

Paulette’s Status

At 11 a.m. EDT (1500 UTC) on Sept. 8, the center of Tropical Storm Paulette was located near latitude 18.4 degrees north and longitude 43.3 degrees west. Paulette is moving toward the northwest near 6 mph (9 kph). The estimated minimum central pressure is 995 millibars. Maximum sustained winds are near 65 mph (100 kph) with higher gusts.

A turn toward the west-northwest or west with a slight increase in forward speed is expected during the next couple of days. Moderate additional strengthening is possible today and Paulette could be near hurricane strength by tonight, Sept. 8.

NASA Researches Tropical Cyclones

For updated forecasts. Visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center