September 2020 – Hurricane And Typhoon Updates

Marie – Eastern Pacific Ocean

Sep. 30, 2020 – NASA Confirms, Heavy Rainfall, Strengthening of Tropical Storm Marie

Tropical Storm Marie has formed in the Eastern Pacific Ocean and NASA satellite data helped confirm the strengthening of the storm. In addition, using a NASA satellite rainfall product that incorporates data from satellites and observations, NASA estimated Marie’s rainfall rates the provided more clues about intensification.

GPM image of Marie — On Sept. 30 at 5:30 a.m. EDT (0930 UTC), NASA’s IMERG estimated Tropical Storm Marie was generating as much as 30 to 40 mm (1.2 to 1.6 inches of rain/dark pink/red) around the center of circulation. Rainfall throughout most of the storm and in bands of thunderstorms west of the center, was occurring between 2 and 15 mm (0.08 to 0.6 inches/yellow and green colors) per hour. The rainfall data was overlaid on infrared imagery from NOAA’s GOES-16 satellite. Credit: NASA/NOAA/NRL

Tropical Depression 18E formed on Sept. 29 by 5 p.m. EDT well southwest of the southwestern coast of Mexico. Twelve hours later the depression strengthened into a tropical storm and renamed Marie.

Marie’s Status on Sept. 30

At 11 a.m. EDT (1500 UTC), the center of Tropical Storm Marie was located near latitude 14.2 degrees north and longitude 113.8 degrees west. Marie is located about 655 miles (1,050 km) south-southwest of the southern tip of Baja California, Mexico and is moving toward the west near 16 mph (26 kph).

A westward to west-northwestward motion is expected through Friday. Maximum sustained winds have increased to near 65 mph (100 kph) with higher gusts. The estimated minimum central pressure is 997 millibars.

Estimating Marie’s Rainfall Rates from Space

NASA’s Integrated Multi-satellitE Retrievals for GPM or IMERG, which is a NASA satellite rainfall product, estimated on Sept. 30 at 5:30 a.m. EDT (0930 UTC) that Tropical Storm Marie was generating as much as 30 to 40 mm (1.2 to 1.6 inches) of rain around the center of circulation. That heavy rainfall near the center is suggestive of hot towering thunderstorms.

A “hot tower” is a tall cumulonimbus cloud that reaches at least to the top of the troposphere, the lowest layer of the atmosphere. It extends approximately 9 miles/14.5 km high in the tropics. These towers are called “hot” because they rise to such altitude due to the large amount of latent heat. Water vapor releases this latent heat as it condenses into liquid. Those towering thunderstorms have the potential for heavy rain. NASA research shows that a tropical cyclone with a hot tower in its eyewall was twice as likely to intensify within six or more hours, than a cyclone that lacks a hot tower.

Rainfall throughout most of the storm and in bands of thunderstorms west of the center was occurring at a rate of between 2 and 15 mm (0.08 to 0.6 inches) per hour.

At the U.S. Naval Laboratory in Washington, D.C., the IMERG rainfall data was overlaid on infrared imagery from NOAA’s GOES-16 satellite to provide the full extent of the storm.

NASA satellite imagery has shown that Marie’s structure has been gradually improving. The National Hurricane Center (NHC) noted that Marie’s center is embedded beneath a central dense overcast feature, and the band of thunderstorms in the western quadrant of the storm has become more pronounced and continuous. In addition, a mid-level eye has begun to form, as observed in microwave satellite data.

What Does IMERG Do?

This near-real time rainfall estimate comes from the NASA’s IMERG, 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.

What IMERG 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. Basically, IMERG fills in the blanks between weather observation stations.

How Other NASA Satellites Help Forecasters

Infrared and water vapor data from NASA’s Aqua, Terra and NASA-NOAA’s Suomi NPP satellite were used to help forecasters assess the environment where Marie was headed. Infrared imagery provides temperature information about cloud tops and sea surface environments. Colder cloud tops indicate stronger storms. Sea surface temperature data are also critical for forecasters because tropical cyclones require ocean temperatures of at least 26.6 degrees Celsius (80 degrees Fahrenheit) to maintain intensity. Warmer waters can help with tropical cyclone intensification, while cooler waters can weaken tropical cyclones.

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 the storms.

Marie’s Forecast

NHC Hurricane Specialist Robbie Berg noted, “The stage appears set for Marie to rapidly intensify during the next couple of days. Water vapor imagery indicates that the easterly [wind] shear over the cyclone has continued to decrease and should be generally low for the next 3 days, and upper-level divergence will also be in place during that period to help ventilate the storm. The thermodynamics are also favorable for fast strengthening, highlighted by sea surface temperatures of 28-29 degrees Celsius and plenty of moisture in the surrounding environment. Due to these conditions, the NHC forecast explicitly shows rapid intensification during the next couple of days, with a peak intensity likely occurring sometime between 48 and 60 hours.”

The National Hurricane Center expects rapid strengthening and Marie is expected to become a hurricane this evening or tonight. Marie could then become a major hurricane by late Thursday, Oct. 1.

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 more information about NASA’s IMERG, visit: https://pmm.nasa.gov/gpm/imerg-global-image

For forecast updates on hurricanes, visit: www.hurricanes.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Kujira – Northwestern Pacific Ocean

Sep. 30, 2020 – NASA Imagery Reveals Kujira Transitioning into an Extratropical Cyclone

Tropical cyclones can become post-tropical before they dissipate, meaning they can become sub-tropical, extra-tropical or a remnant low-pressure area. NASA’s Aqua satellite provided a visible image that showed Typhoon Kujira transitioning into an extra-tropical storm, and the effects of strong wind shear on the system.

Aqua image of Kujira — On Sept. 30 at 0300 UTC (Sept. 29 at 11 p.m. EDT), the MODIS instrument aboard NASA’s Aqua satellite provided a visible image of Kujira that showed the storm had transitioned into an extra-tropical cyclone in the Northwestern Pacific Ocean. Credit: NASA/NRL

What is a Post-tropical Storm?

A post-tropical storm is a generic term for a former tropical cyclone that no longer possesses sufficient tropical characteristics to be considered a tropical cyclone. Former tropical cyclones that have become fully extratropical, subtropical, or remnant lows are classes of post-tropical cyclones. They no longer possesses sufficient tropical characteristics to be considered a tropical cyclone. However, post-tropical cyclones can continue carrying heavy rains and high winds.

What is an Extra-tropical Storm?

Often, a tropical cyclone will transform into an extra-tropical cyclone as it recurves toward the poles (north or south, depending on the hemisphere the storm is located in). An extra-tropical cyclone is a storm system that primarily gets its energy from the horizontal temperature contrasts that exist in the atmosphere.

Tropical cyclones have their strongest winds near the earth’s surface, while extra-tropical cyclones have their strongest winds near the tropopause – about 8 miles (12 km) up. Tropical cyclones, in contrast, typically have little to no temperature differences across the storm at the surface and their winds are derived from the release of energy due to cloud/rain formation from the warm moist air of the tropics.

Visible NASA Imagery Shows the Transition

Visible imagery from NASA’s Aqua satellite revealed Kujira’s extra-tropical transition under way as the storm appeared asymmetric due to wind shear.

On Sept. 30 at 0300 UTC (Sept. 29 at 11 p.m. EDT), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite provided a visible image of the storm. Kujira’s center of circulation was surrounded by wispy clouds, while powerful southwesterly vertical wind shear (outside winds that push against a tropical cyclone) had pushed the bulk of clouds and showers northeast of the center.

Kujira’s Final Advisory

At 5 p.m. EDT (2100 UTC) on Sept. 29, the center of Post-Tropical Cyclone Kujira was located near latitude 38.6 degrees north and longitude 159.4 degrees east. That is about 802 nautical miles east of Misawi, Japan. The post-tropical cyclone was moving toward the northeast. As it was transitioning, it weakened from typhoon strength to tropical storm strength. Maximum sustained winds had decreased to near 55 knots (63 mph/102 kph).

In the last bulletin by the Joint Typhoon Warning Center at that time, forecasters noted “Environmental analysis indicates the system has drifted into high vertical wind shear, [greater than 40 knots (46 mph/74 kph) and cold (less than 25 degrees Celsius/77 Fahrenheit) sea surface temperatures] and has entered into the baroclinic zone.” Tropical cyclones need sea surface temperatures of at least 26.6 degrees Celsius/80 degrees Fahrenheit to maintain strength.

A baroclinic zone is a region in which a temperature gradient exists on a constant pressure surface. Baroclinic zones are favored areas for strengthening and weakening systems while barotropic systems, on the other hand, do not exhibit significant changes in intensity. In addition, wind shear is characteristic of a baroclinic zone.

Kujira is expected to complete extratropical transition and weaken to a post-tropical depression by the afternoon of September 30, 2020.

NASA Researches Earth from Space

By Rob Gutro
NASA’s Goddard Space Flight Center

Kujira – Northwestern Pacific Ocean

Sep. 29, 2020 – NASA’s Infrared View of Typhoon Kujira

NASA’s Terra satellite used infrared light to identify strongest storms and coldest cloud top temperatures in Typhoon Kujira as it tracked through the northwestern Pacific Ocean.

Terra image of Kujira — On Sept. 29 at 7:40 a.m. EDT (1140 UTC), the MODIS instrument aboard NASA’s Terra satellite gathered temperature information about Typhoon Kujira’s cloud tops. MODIS found the most powerful thunderstorms (red) were wrapping around the eye where temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 Celsius). Credit: NASA/NRL

Infrared Data Reveals Most Powerful Storms

Infrared data provides temperature information about the cloud tops of the many thunderstorms that make up a tropical cyclone. The strongest thunderstorms reach high into the atmosphere and have the coldest cloud top temperatures. Tropical cyclones do not always have uniform strength, so infrared data helps forecasters know the location of the strongest side of a storm.

On Sept. 29 at 7:40 a.m. EDT (1140 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Terra satellite gathered temperature information about Typhoon Kujira’s cloud tops. MODIS found the most powerful thunderstorms had temperatures that were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 Celsius). Those strongest storms were found wrapping around the eye. In addition, a large band of fragmented thunderstorms east of the center contained storms with those temperatures.

Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

Typhoon Kujira’s Status on Sept. 29

At 11 a.m. EDT (1500 UTC) on Sept. 29, Typhoon Kujira’s maximum sustained winds were near 65 knots (75 mph/120 kph), making it a Category One hurricane on the Saffir-Simpson Hurricane Wind Scale. Kujira was far from land areas, centered near latitude 36.5 degrees north and longitude 156.4 degrees east, about 814 nautical miles east of Yokosuka, Japan. Kujira was moving to the north-northeast. It is no threat to land areas.

Forecasters at the Joint Typhoon Warning Center in Honolulu, Hawaii noted that Kujira is forecast to become extra-tropical later in the day on Sept. 29. It is then expected to begin a weakening trend.

NASA Researches Tropical Cyclones

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.

NASA’s Terra satellite is one in a fleet of NASA satellites that provide data for hurricane research.

By Rob Gutro
NASA’s Goddard Space Flight Center

Kujira – Northwestern Pacific Ocean

Sep. 28, 2020 – NASA Casts an Infrared Eye on Tropical Storm Kujira’s Very Cold Cloud Tops

NASA analyzed the cloud top temperatures in Tropical Storm Kujira using infrared light to determine the strength of the storm. Infrared imagery revealed that the strongest storms were around Kujira’s center and in a band of thunderstorms on the western side of the storm.

The low-pressure area designated System 97W consolidated and strengthened into a tropical depression on Sept. 26 by 5 p.m. EDT (2100 UTC). On Sept. 27 at 11 a.m. EDT (1500 UTC), the Joint Typhoon Warning Center noted that the depression had strengthened into a tropical storm and was renamed Kujira.

An Infrared View of Kujira

One of the ways NASA researches tropical cyclones is by using infrared data that provides temperature information. Cloud top temperatures identify where the strongest storms are located. The stronger the storms, the higher they extend into the troposphere, and the colder the cloud top temperatures.

On Sept. 28 at 6:15 a.m. EDT (1015 UTC) NASA’s Aqua satellite analyzed Kujira using the Moderate Resolution Imaging Spectroradiometer or MODIS instrument. The MODIS imagery showed the strongest storms were around Kujira’s center of circulation and in a fragmented band of thunderstorms in the western quadrant. Persistent deep convection was also obscuring the low-level circulation center.

Temperatures in those areas were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). An 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 shown that cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain.

NASA provides data to tropical cyclone meteorologists so they can incorporate it in their forecasts.

Kujira’s Status on Sept. 28

At 11 a.m. EDT (1500 UTC) on Sept. 28, the center of Tropical Storm Kujira was located near latitude 29.7 degrees north and longitude 153.3 degrees east. That is about 286 nautical miles north of Minami Tori Shima. Minami Tori Shima is an isolated Japanese coral atoll located about 1,148 miles (1,848 kilometers) southeast of Tokyo, Japan.

Kujira had maximum sustained winds near 45 knots (52 mph/83 kph) with higher gusts. The storm is moving north through the open waters of the Northwestern Pacific Ocean.

Kujira’s Forecast

Kujira forecast to intensify and track north-northeastward through next 24 hours as it rounds a subtropical ridge (elongated area of high pressure.) Forecasters at the Joint Typhoon Warning Center expect Kujira will begin extratropical transition as it interacts with mid-latitude westerlies (winds) and encounters increasing vertical wind shear (outside winds that can weaken and tear a tropical cyclone apart).

NASA Researches Earth from Space

By Rob Gutro
NASA’s Goddard Space Flight Center

Beta – Atlantic Ocean

Sep. 25, 2020 – NASA Finds Post-Tropical Storm Beta’s Clouds Blanketing the Southeastern U.S.

NASA’s Terra satellite obtained visible imagery of Post-Tropical Cyclone Beta as it continued moving slowly through the Tennessee Valley. Clouds associated with the low-pressure area looked like a large white blanket draped across much of the southeastern U.S.

Terra image of Beta — On Sept. 24 at 1:30 p.m. EDT NASA’s Terra satellite provided a visible image of Post-Tropical Cyclone Beta moving through the Tennessee Valley. Image Courtesy: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).

On Sept. 25, NOAA’s National Weather Service Weather Prediction Center (WPC) in College Park, Md. noted Beta was moving slowly northeast. It was centered about 60 miles (100 km) north-northeast of Birmingham, Alabama.

A NASA Satellite View

The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite captured a visible image of Post Tropical Storm Beta moving slowly through the Tennessee Valley on Sept. 24 and the center of the storm did not move much by Sept. 25. The MODIS image revealed a blanket of clouds associated with Beta stretched from Mississippi to the Carolinas.

The Valley is the drainage basin of the Tennessee River and is largely within the state of Tennessee. It extends from southwestern Kentucky to north Georgia and from northeast Mississippi to the mountains of North Carolina and Virginia.

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

Beta’s Status on Sept. 25

On Sept. 25, Beta’s center had become less determinant in the pressure and wind fields. In addition, the heavy rainfall threat with Beta has diminished.

At 5 a.m. EDT (0900 UTC) on Sept. 25, NOAA’s WPC issued the last public advisory issued on this system. At that time, the center of Post-Tropical Cyclone Beta was located near latitude 34.3 degrees north and longitude 86.3 degrees west. The post-tropical cyclone was moving toward the northeast near 10 mph (17 kph) until it becomes indistinguishable within the background wind and pressure field by mid-afternoon Friday. Maximum sustained winds are near 10 mph (20 kph) with higher gusts.

WPC forecasts rainfall totals of 1 to 3 inches expected through Friday from the southern Appalachians into the Piedmont of South and North Carolina. Isolated flash, urban, and small stream flooding is possible.

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.

For local weather forecasts, visit: www.weather.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Lowell – Eastern Pacific Ocean

Sep. 25, 2020 – NASA Finds Wind Shear Displacing Lowell’s Strongest Storms

NASA’s Aqua satellite provided an infrared view of Tropical Storm Lowell that revealed the effects of outside winds battering the storm.

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.

Aqua image of Lowell — On Sept. 25 at 5:45 a.m. EDT (0945 UTC), the MODIS instrument that flies aboard NASA’s Aqua satellite gathered infrared data on Lowell that confirmed wind shear was adversely affecting the storm. Persistent westerly vertical wind shear showed strongest storms (yellow) pushed east of the center where cloud top temperatures were as cold as minus 50 degrees Fahrenheit (minus 45.5 Celsius). Credit: NASA/NRL

NASA’s Aqua Satellite Reveals Effects of Wind Shear

Infrared light is a tool used to analyze the strength of storms in tropical cyclones by providing temperature information about a system’s clouds. The strongest thunderstorms that reach highest into the atmosphere have the coldest cloud top temperatures. This temperature information can also tell forecasters if the strongest storms in a tropical cyclone are pushed away from the center, indicating wind shear.

On Sept. 25 at 5:45 a.m. EDT (0945 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite gathered infrared data on Lowell that confirmed wind shear was adversely affecting the storm. Westerly vertical wind shear pushed strongest storms east of the center where cloud top temperatures are as cold as minus 50 degrees Fahrenheit (minus 45.5 Celsius). That small area of strongest storms was located 100 nautical miles east of Lowell’s center.

NOAA’s National Hurricane Center noted in their discussion today, “The areal coverage of Lowell’s convection and its distance from the center already put it on the margins of what is considered organized deep convection.”

Status of Tropical Storm Lowell

At 5 a.m. EDT (0900 UTC), the center of Tropical Storm Lowell was located near latitude 21.6 degrees north and longitude 128.0 degrees west. That is about 1,160 miles (1,865 km) west of the southern tip of Baja California, Mexico. Lowell was moving toward the west near 12 mph (19 kph), and this general motion, with some increase in forward speed, is expected to continue into early next week.

Maximum sustained winds are near 40 mph (65 kph) with higher gusts. Gradual weakening is forecast, and Lowell is expected to become a remnant low today, Sept. 25.

Forecast for Lowell

“Cold waters and increasing west-to-southwesterly wind shear expected over the next 24 hours should finally do the convection in,” noted Robbie Berg, a hurricane specialist at NOAA’s National Hurricane Center in Miami, Fla. That should cause Lowell to lose tropical cyclone status on Friday. “Even stronger [wind] shear is forecast to cause the remnant low to gradually weaken through the end of the 5-day forecast period.”

NASA Researches Tropical Cyclones

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

By Rob Gutro
NASA’s Goddard Space Flight Center

Dolphin – Northwestern Pacific Ocean

Sep. 24, 2020 – NASA Nets Dolphin as an Extratropical Storm

NASA’s Aqua satellite caught a visible image of Dolphin after it passed east central Japan on Sept. 24, where it became an extratropical storm in the Northwestern Pacific Ocean.

Aqua image of Dolphin — NASA’s Aqua satellite provided a visible image of Extratropical Storm Dolphin in the Northwestern Pacific Ocean at 11:35 p.m. EDT on Sept. 23 (0335 UTC on Sept. 24). Image Courtesy: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).

At 11 p.m. EDT on Sept. 23 (0300 UTC on Sept. 24) the Joint Typhoon Warning Center (JTWC) noted, “Animated multispectral satellite imagery shows the ragged low level circulation has become quasi-stationary and fully exposed as the rapidly decaying central convection sheared 140 plus nautical miles to the east-northeast. Analysis indicates that tropical cyclone Dolphin now fully embedded in the baroclinic zone and has become extra-tropical.”

Strong vertical wind shear from the west-southwest was battering Dolphin and pushing the bulk of clouds to the east-northeast. Wind shear occurs when winds outside of a tropical cyclone blow against it and adversely affect its circulation by displacing clouds and precipitation and weakening the system.

Dolphin on Sept. 24

At 11 p.m. EDT on Sept. 23 (0300 UTC on Sept. 24) the center of Dolphin was located near latitude 33.1 degrees north and longitude 141.8 degrees east. That is about 175 nautical miles southeast of Yokosuka, Japan. Dolphin was barely moving to the south at 1 knot and had maximum sustained winds near 30 knots (35 mph/55 kph).

NASA’s Aqua Satellite View

The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite captured a visible image of Dolphin at 11:35 p.m. EDT on Sept. 23 (0335 UTC on Sept. 24). The image showed the storm appeared more elongated. That is an indication that the storm was weakening and it had become extratropical.

What is an Extra-tropical Storm?

Tropical cyclones have their strongest winds near the earth’s surface, while extra-tropical cyclones have their strongest winds near the tropopause – about eight miles (12 km) up. Also, tropical cyclones, in contrast, typically have little to no temperature differences across the storm at the surface and their winds are derived from the release of energy due to cloud/rain formation from the warm moist air of the tropics.

Dolphin’s Final Forecast

Forecasters at the JTWC noted, “The remnant storm-force cold-core low [pressure area] will drift slowly poleward [north] and deeper into the cold polar air mass. There is also a distinct possibility that the cyclone will remain quasi-stationary and dissipate.”

About NASA’s Worldview and Aqua Satellite

NASA’s Aqua satellite is one in a fleet of NASA satellites that provide data for hurricane research.

By Rob Gutro
NASA’s Goddard Space Flight Center

Beta – Atlantic Ocean

Sep. 24, 2020 – NASA Estimating Beta’s Rains Moving into the Tennessee Valley

Using a NASA satellite rainfall product that incorporates data from satellites and observations, NASA estimated Post-tropical Cyclone Beta’s rainfall rates as it moved over Mississippi, Alabama and Tennessee. Beta continues a steady northeast track into Mississippi, bringing heavy rainfall across Mississippi into the Tennessee Valley.

IMERG data on Beta — NASA’s IMERG estimated on Sept. 24 at 3:30 a.m. EDT (0730 UTC), that Beta was generating as much as 10 to 15 mm (0.40 to 0.60 inches) of rain per hour over Alabama. Lighter rainfall rates were occurring over Mississippi and Tennessee at the time of the image. Rainfall throughout most of the storm was estimated as falling at a rate between 0.2 and 1 mm (0.007 to 0.4 inches) per hour. The rainfall data was overlaid on infrared imagery from NOAA’s GOES-16 satellite. Credit: NASA/NOAA/NRL

Beta’s Status on Sept. 24

NOAA’s National Weather Service Weather Prediction Center (WPC) in College Park, Md. noted that at 5 a.m. EDT (0900 UTC) the center of Post-Tropical Cyclone Beta was located near latitude 31.9 degrees north and longitude 91.0 degrees west. The post-tropical cyclone is moving toward the northeast near 12 mph (19 kph). Maximum sustained winds are near 30 mph (45 kph) with higher gusts.

Estimating Beta’s Rainfall Rates from Space

NASA’s Integrated Multi-satellitE Retrievals for GPM or IMERG, which is a NASA satellite rainfall product, estimated on Sept. 24 at 3:30 a.m. EDT (0730 UTC), Beta was generating as much as 10 to 15 mm (0.40 to 0.60 inches) of rain per hour over Alabama. Lighter rainfall rates were occurring over Mississippi and Tennessee at the time of the image. Rainfall throughout most of the storm was estimated as falling at a rate between 0.2 and 1 mm (0.007 to 0.4 inches) per hour.

At the U.S. Naval Laboratory in Washington, D.C., the IMERG rainfall data was overlaid on infrared imagery from NOAA’s GOES-16 satellite to provide a full extent of the storm.

Watches and Warnings

On Sept. 24, Flash Flood Watches were in effect from southwestern Mississippi to parts of northern Alabama, and southern Middle Tennessee.

NOAA’s WPC said, “Rainfall totals of 2 to 4 inches are expected through early Friday from central to northern Mississippi, across the Middle Tennessee Valley and into the Southern Appalachians. Isolated flash and urban flooding is possible, as well as isolated minor river flooding on smaller rivers. An isolated tornado or two are possible this afternoon across Southern Alabama.”

Beta’s Forecast

Beta is expected to continue moving in a northeasterly direction for the next day and a half. Some weakening is forecast for the next 36 hour before weakening into a frontal system.

What Does IMERG Do?

What the IMERG 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. Basically, IMERG fills in the blanks between weather observation stations.

NASA Researches Tropical Cyclones

For more information about NASA’s IMERG, visit: https://pmm.nasa.gov/gpm/imerg-global-image

For forecast updates on hurricanes, visit: www.hurricanes.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Teddy – Atlantic Ocean

Sep. 24, 2020 – Post-Tropical Storm Teddy in NASA Newfoundland Nighttime View

NASA-NOAA’s Suomi NPP satellite provided an infrared image of Post-tropical cyclone Teddy over the province of Newfoundland, Canada in the early morning hours of Sept. 24.

Suomi NPP image of Teddy — NASA-NOAA’s Suomi NPP satellite provided a nighttime view of Post-Tropical Cyclone Teddy over Newfoundland, Canada at 1:40 a.m. EDT (0540 UTC) on Sept. 24. The nighttime lights of Newfoundland can be seen somewhat through Teddy’s clouds, and the nighttime lights of Nova Scotia were visible, revealing the Teddy had moved past the province. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)

Teddy’s Last Advisory

At 11 p.m. EDT on Sept. 23 (0300 UTC on Sept. 24), NOAA’s National Hurricane Center (NHC) issued the final advisory on Post-Tropical Cyclone Teddy. At that time, the center of Post-Tropical Cyclone Teddy was located near latitude 51.0 degrees north and longitude 57.3 degrees west based on the Marble Mountain, Newfoundland, radar and surface observations along the west coast of Newfoundland. The post-tropical cyclone was moving toward the north-northeast near 32 mph (52 kph), and this general motion is expected to continue through Thursday. Maximum sustained winds were near 50 mph (85 kph) with higher gusts. The estimated minimum central pressure is 975 millibars.

The center of Teddy moved closer to the northwestern Newfoundland coast overnight.

NASA’s Night-Time View

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a nighttime image of Post-Tropical Storm Teddy over Newfoundland, Canada. The image was taken at 1:40 a.m. EDT (0540 UTC) on Sept. 24. The nighttime lights of Newfoundland can be seen somewhat through Teddy’s clouds, and the nighttime lights of Nova Scotia were visible, revealing that Teddy had moved past the province.

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

Teddy’s Final Fate

On the forecast track, Teddy is expected to move into the Labrador Sea today, Sept. 24 before merging with a larger extratropical low-pressure area.

About NASA’s EOSDIS Worldview

NASA Researches Earth from Space

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

By Rob Gutro
NASA’s Goddard Space Flight Center

Lowell – Eastern Pacific Ocean

Sep. 23, 2020 – NASA-NOAA Satellite Finds Wind Shear Affecting Tropical Storm Lowell

NASA-NOAA’s Suomi NPP satellite passed over the Eastern North Pacific Ocean and captured a visible image of Tropical Storm Lowell that revealed the storm was dealing with wind shear.

Suomi NPP image of Lowell — NASA-NOAA’s Suomi NPP satellite captured a visible image of Tropical Storm Lowell on Sept. 23 as it continued moving west through the open waters of the Eastern North Pacific Ocean. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)

Wind shear is caused by winds outside of a tropical cyclone that are blowing against it at different altitudes and directions. Wind shear weakens tropical cyclones by adversely affecting their circulation. Wind shear can elongate a storm and make it spin more slowly, leading to weakening.

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a visible image of Lowell on Sept. 23. Around the time of the Suomi NPP image, the National Hurricane Center noted a band of deep convection and thunderstorms had continued over the eastern quadrant of the storm, but the center was exposed and was located west of that band of thunderstorms. Lowell was being affected by moderate northwesterly wind shear which is not expected to abate much.

By 5 p.m. EDT on Sept. 23, Lowell was maintaining strength with a few bands of deep convection and developing thunderstorms located 30 nautical miles or more to the east of the exposed center.

Lowell’s Status on Sept. 24

At 5 a.m. EDT (0900 UTC) on Sept.24, the center of Tropical Storm Lowell was located near latitude 21.2 degrees north and longitude 123.7 degrees west. That is about 890 miles (1,435 km) west of the southern tip of Baja California, Mexico.

Lowell was moving toward the west-northwest near 10 mph (17 kph). Maximum sustained winds are near 45 mph (75 kph) with higher gusts. Gradual weakening is forecast to begin by late Thursday.

Lowell’s Forecast

NHC said a turn toward the west is expected Thursday morning, with that heading and a gradual increase in forward speed continuing through early next week. Lowell is expected to weaken to a tropical depression by late Friday and become a remnant low by early Saturday.

NASA Researches Tropical Cyclones

By Rob Gutro
NASA’s Goddard Space Flight Center