Gamma – Atlantic Ocean

Oct. 06, 2020 – What Happened to Gamma’s Remnants?

The remnant low-pressure area of Gamma was located off the north coast of Yucatan at 8 a.m. EDT. Gamma has since moved inland and is forecast to dissipate on Wednesday.

By Rob Gutro
NASA’s Goddard Space Flight Center


Oct. 05, 2020 – NASA Imagery Reveals Tropical Storm Gamma Battered by Wind Shear

NASA’s Terra satellite obtained visible imagery of Tropical Storm Gamma being battered by outside winds in the south central Gulf of Mexico. Over the weekend of Oct. 3 and 4, Gamma tracked over Mexico’s Yucatan Peninsula.

Animation of Gammas movements
This animation from Oct. 1 to 4 shows visible imagery from NOAA/NASA’s Suomi NPP satellite of Tropical Storm Gamma moving through the Caribbean Sea, making landfall over Mexico’s Yucatan and moving into the southern Gulf of Mexico, just north of Mexico’s Yucatan Peninsula. Image Courtesy: NOAA/NASA

Tropical Depression 25 formed on Oct. 2 by 11 a.m. EDT over the northwestern Caribbean Sea. At the time of formation, NOAA’s National Hurricane Center (NHC) issued warnings and watches for a portion of the Yucatan Peninsula of Mexico. By 8 p.m. EDT, the depression strengthened into a tropical storm and re-named Gamma.

Gamma brought heavy rainfall to the Yucatan Peninsula over the weekend of Oct. 3 and 4. On Oct. 3, NHC noted, “Surface observations and satellite images indicate that the center of Tropical Storm Gamma made landfall in the northeast Yucatan Peninsula near Tulum, Mexico, around 11:45 a.m. CDT (12:45 p.m. EDT). The storm was very close to hurricane strength at landfall, with maximum sustained winds near 70 mph (110 mph) with higher gusts.”

The storm had weakened after tracking over the peninsula. By 5 p.m. EDT, Gamma’s center had moved off the northern coast of the Yucatan Peninsula and appeared to be stalled. The storm did not move much by Oct. 5.

Watches and Warnings on Oct. 5

On Oct. 5, the NHC posted a warning and a watch. A Tropical Storm Warning is in effect for north and west of Cancun to Dzilam, Mexico A Tropical Storm Watch is in effect from west of Dzilam to Campeche, Mexico.

Gamma’s Wind Shear Troubles  

The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite captured a visible image of Tropical Storm Gamma on Oct. 5.

Terra image of Gamma
On Oct. 5, 2020 at 1:30 p.m. EDT, NASA’s Terra satellite provided a visible image of Tropical Storm Gamma in the southern Gulf of Mexico, just north of Mexico’s Yucatan Peninsula. Image Courtesy: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).

Gamma is a strongly sheared tropical storm that has been meandering just north of the northern coast of the Yucatan Peninsula of Mexico. The MODIS image revealed the strongest thunderstorms were pushed far to the north of the center of circulation by those outside winds (wind shear) from the south.

Infrared imagery showed that strong convective cloud tops colder than minus 80 degrees Celsius were more than 60 nautical miles north and northeast of the well-defined and fully exposed low-level circulation center. That southerly wind shear was pushing those strong storms north of the center.

NHC noted that the Decay SHIPS intensity computer forecast model does indicate a very brief period of decreasing wind shear magnitude just prior to landfall around the 24-hour period. Afterward, the shear, once again, increases and the storm will weaken.

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

Gamma’s Status on Oct. 5

At 2 p.m. EDT (1800 UTC), the center of Tropical Storm Gamma was located near latitude 22.3 degrees north and longitude 87.9 degrees west. It was centered about 135 miles (220 km) north-northwest of Cozumel, Mexico.

Gamma is moving toward the southwest near 4 mph (7 kph), and this general motion is expected to continue through Wednesday morning. Maximum sustained winds have decreased to near 40 mph (65 kph) with higher gusts.  The estimated minimum central pressure is 1003 millibars.

Key Messages

NHC issued two key messages about Gamma, as the storm is expected to continue affecting the Yucatan Peninsula:

Through midweek, Gamma is expected to produce an additional 3 to 6 inches of rainfall with isolated maximum amounts of 8 inches across portions of the Mexican states of Yucatan, Campeche, and Tabasco. This rainfall may produce significant flash flooding.

Tropical storm conditions are likely in portions of the Tropical Storm Warning area along the northern coast of the Yucatan Peninsula for a brief period this afternoon. Tropical Storm conditions are possible within the Tropical Storm Watch area.

Gamma’s Forecast 

On the forecast track, the center of Gamma should move inland over the northwest coast of the Yucatan Peninsula Tuesday night and remain inland through Thursday. Gradual weakening is forecast, and Gamma is expected to become a depression this evening and degenerate to a post-tropical remnant low tonight.

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.

By Rob Gutro
NASA’s Goddard Space Flight Center

Chan-hom – Northwestern Pacific Ocean

Oct. 05, 2020 – NASA Imagery Reveals Tropical Storm Chan-hom’s Skewed Structure

NASA’s Terra satellite obtained visible imagery of Tropical Storm Chan-hom as it continued moving though the Northwestern Pacific Ocean. The imagery revealed that the center of circulation was exposed and its strongest storms were south of the center.

Terra image of Chan-hom
On Oct. 5, 2020, NASA’s Terra satellite provided a visible image of Tropical Storm Chan-hom several hundred miles northwest of Guam (lower right). Image Courtesy: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).

Tropical Depression 16W formed on Oct. 4 and strengthened into a tropical storm on Oct 5. Once it reached tropical storm strength, it was re-named Chan-hom.  Laos submitted the name Chan-hom to the World Meteorological Organization list. The name is a type of tree in Laos.

NASA Satellite View: Chan-hom’s Organization

The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite captured a visible image of Tropical Storm Chan-hom on Oct. 5 that showed a couple of things were occurring in the storm. First, bands of thunderstorms were wrapping into a partially exposed low-level circulation center. Second, there was building convection and thunderstorms occurring over the southern quadrant of the storm, giving it an appearance of a backwards letter “C” on satellite imagery. The storm is expected to strengthen over the next three days and when it does, it will likely develop a more circular shape.

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

Chan-hom’s Status on Oct. 5

At 11 a.m. EDT (1500 UTC) on Oct. 5, Chan-hom was centered near latitude 23.0 degrees north and longitude 139.2 degrees east. That is about 738 miles south of Yokosuka, Japan. Chan-hom is moving north and has maximum sustained winds of 35 knots (40 mph/64 kph).

Chan-hom’s Forecast

The Joint Typhoon Warning Center noted, “Chan-hom is forecast to track generally northwestward along the southwestern periphery of a sub-tropical ridge (elongated area of high pressure) over the next three days. During this time, the system will steadily intensify to a peak intensity of 85 knots (98 mph/157 kph) by three days largely due to the continued low vertical wind shear and warm sea surface temperatures.”

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.

By Rob Gutro
NASA’s Goddard Space Flight Center

Delta – Atlantic Ocean

Oct. 05, 2020 – NASA Gages Tropical Storm Delta’s Strength in Infrared

NASA’s Aqua satellite analyzed Tropical Storm Delta in infrared imagery as it moved through the Caribbean Sea. The imagery provided cloud top temperatures to identify the strongest areas within the storm.

AIRS image of Delta
On Oct. 5 at 3:05 a.m. EDT (0705 UTC) NASA’s Aqua satellite analyzed Tropical Storm Delta 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) around the center of circulation. Credit: NASA JPL/Heidar Thrastarson

Potential Tropical Cyclone 26 formed in the Caribbean Sea on Sunday, Oct. 4 by 5 p.m. EDT. Six hours later, the National Hurricane Center (NHC) classified it as Tropical Depression 26. By 8 a.m. EDT, satellite imagery helped confirm that the depression had strengthened into a tropical storm. At that time, it was given the name Delta.

 Analyzing Delta’s Temperatures and 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 Delta and gave insight into the size of the storm and its rainfall potential.

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 Oct. 5 at 3:05 a.m. EDT (0705 UTC) NASA’s Aqua satellite analyzed Tropical Storm Delta 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) around the center of circulation. NASA research has shown that cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain.

When meteorologists studied satellite imagery, including infrared imagery, it was noted that deep convection (rising air that forms the thunderstorms that make up a tropical cyclone) had been steadily improving in both vertical depth and structure of the storm since 2 a.m. EDT. Even the cloud pattern was becoming more circular with upper-level outflow of air at the top of the storm now having become established in all quadrants. That is an indication of improvement in a storm’s structure.

NHC noted, “However, there are still some indications in satellite imagery that the low-level and the mid-upper-level circulations are not yet vertically aligned, with the low-level center still located just inside the northern edge of the convective cloud shield.”

Eight hours after the AIRS image, the convective structure of Delta continued to improve. Earlier microwave data and early-light visible satellite imagery showed that the center of the tropical cyclone re-formed farther south within the area of deep convection.

Warnings and Watches on Oct. 5

NOAA’s National Hurricane Center has issued a number of watches and warnings for Delta on Oct. 5. A Hurricane Warning is in effect for Cuba’s province of Pinar del Rio. A Tropical Storm Warning is in effect for the Cayman Islands including Little Cayman and Cayman Brac, and for the Isle of Youth.

A Hurricane Watch is in effect for the Cuban province of Artemisa and for the Isle of Youth. A Tropical Storm Watch is in effect for the Cuban province of La Habana.

Delta’s Status

At 11 a.m. EDT (1500 UTC) on Oct. 5, the center of Tropical Storm Delta was located near latitude 16.4 degrees north and longitude 78.6 degrees west. Delta is centered about 135 miles (215 km) south of Negril, Jamaica and about 265 miles (425 km) southeast of Grand Cayman.

Delta is moving toward the west near 7 mph (11 kph), and a turn toward the west-northwest is forecast later today. A faster northwestward motion is expected on Tuesday (Oct. 6) and Wednesday (Oct. 7).  Maximum sustained winds have increased to near 45 mph (75 kph) with higher gusts. The estimated minimum central pressure is 1002 millibars.

 Delta’s Forecast

NHC expects additional strengthening during the next few days, and Delta is expected to become a hurricane on Tuesday before it nears western Cuba. On the forecast track, the center of Delta is expected to move away from Jamaica later today, move near or over the Cayman Islands early Tuesday, and approach western Cuba Tuesday afternoon or evening. Delta is forecast to move into the southeastern Gulf of Mexico Tuesday night, and be over the south-central Gulf of Mexico on Wednesday.

About NASA’s AIRS Instrument

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

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

NASA Research

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

More information about AIRS can be found at: https://airs.jpl.nasa.gov/

By Rob Gutro
NASA’s Goddard Space Flight Center

Marie – Eastern Pacific Ocean

Oct. 02, 2020 – NASA Finds Heavy Rainfall Ringing Major Hurricane Maria’s Eye

Imagine being able to look down at a storm from orbit in space, and provide data that lets scientists calculate the rate in which rain is falling throughout it. That is what a NASA satellite rainfall product does as it incorporates data from satellites and observations. NASA found very heavy rainfall ringing around the compact eye of Major Hurricane Marie.

IMERG data from Marie
On Oct. 2 at 4:30 a.m. EDT (0830 UTC), NASA’s IMERG estimated Hurricane Maria was generating as much as 50 mm (2 inches of rain/dark red) around the center of circulation. Rainfall throughout most of the storm was occurring between 3 and 20 mm (0.1 to 0.8 inches/yellow, green and pink colors) per hour. The rainfall data was overlaid on infrared imagery from NOAA’s GOES-16 satellite. Credit: NASA/NOAA/NRL

Maria’s Status on Oct. 2

At 5 a.m. EDT (0900 UTC), NOAA’s National Hurricane Center (NHC) reported Hurricane Marie was a Category 4 storm on the Saffir-Simpson Hurricane Wind Scale. The center of Hurricane Marie was located near latitude 16.2 degrees north and longitude 123.2 degrees west. Fortunately, Marie is far from land areas. It is centered about 980 miles (1,580 km) west-southwest of the southern tip of Baja California, Mexico.

Marie was moving toward the west-northwest near 15 mph (24 kph). Maximum sustained winds have increased to near 130 mph (215 kph) with higher gusts. Hurricane-force winds extend outward up to 25 miles (35 km) from the center and tropical-storm-force winds extend outward up to 125 miles (205 km). The estimated minimum central pressure is 947 millibars.

Estimating Maria’s Rainfall Rates from Space

NASA’s Integrated Multi-satellitE Retrievals for GPM or IMERG, which is a NASA satellite rainfall product, estimated on Oct. 2 at 4:30 a.m. EDT (0830 UTC), Hurricane Maria was generating as much as 50 mm (2 inches) of rain in the eyewall, ringing around the eye. Rainfall throughout most of the storm was occurring between 3 and 20 mm (0.1 to 0.8 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 picture of the storm.

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.

Instead, 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.

Marie’s Future

Additional strengthening is expected today, with weakening forecast to begin on Saturday, Oct. 3. A motion toward the west-northwest or northwest with a gradual decrease in forward speed is expected during the next several days.

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

Marie – Eastern Pacific Ocean

Oct. 01, 2020 – NASA Finds Hurricane Marie Rapidly Intensifying

NASA infrared imagery revealed that Hurricane Marie is rapidly growing stronger and more powerful. Infrared imagery revealed that powerful thunderstorms circled the eye of the hurricane as it moved through the Eastern Pacific Ocean.

Aqua image of Marie
On Oct. 1 at 4:10 a.m. EDT (0910 UTC) NASA’s Aqua satellite analyzed Hurricane Marie’s cloud top temperatures and found strongest storms (yellow) were around Marie’s center of circulation. Temperatures in those areas were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). Strong storms with cloud top temperatures as cold as minus 70 degrees (red) Fahrenheit (minus 56.6. degrees Celsius) surrounded the center. Credit: NASA/NRL

NOAA’s National Hurricane Center (NHC) expects Marie to become a major hurricane late on Oct. 1.  

Infrared Imagery Reveals a More Powerful Marie

One of the ways NASA researches tropical cyclones is 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 Oct. 1 at 4:10 a.m. EDT (0910 UTC) NASA’s Aqua satellite analyzed the storm using the Moderate Resolution Imaging Spectroradiometer or MODIS instrument. Hurricane Marie’s cloud top temperatures and found strongest storms were around Marie’s center of circulation. Temperatures in those areas 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.

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

At 5 a.m. EDT on Oct 1, NHC Hurricane Specialist Andrew Latto noted, “Recent microwave data and satellite images indicate that Marie has become much better organized over the past several hours, with a nearly completely closed eye noted in a (12:51 a.m. EDT) 0451Z AMSU composite microwave overpass.”

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

Marie’s Status on Oct. 1

At 5 a.m. EDT (0900 UTC), the center of Hurricane Marie was located near latitude 14.8 degrees north and longitude 118.1 degrees west. It is about 775 miles (1,245 km) southwest of the southern tip of Baja California, Mexico. Marie is moving toward the west near 17 mph (28 kph), and this general motion is expected to continue through tonight, followed by a gradual turn toward the west-northwest with decreasing forward speed.

Maximum sustained winds are near 90 mph (150 kph) with higher gusts. Hurricane-force winds extend outward up to 15 miles (30 km) from the center and tropical-storm-force winds extend outward up to 70 miles (110 km). The estimated minimum central pressure is 983 millibars.

Marie’s Forecast

Rapid strengthening is forecast by the National Hurricane Center. Marie is expected to become a major hurricane by tonight with some additional strengthening possible through Friday. Marie is then forecast to begin weakening 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.

For updated forecasts, visit: www.hurricanes.gov

By Rob Gutro 
NASA’s Goddard Space Flight Center

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

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.

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.

Aqua image of Kujira
On Sept. 28 at 6:15 a.m. EDT (1015 UTC) NASA’s Aqua satellite analyzed Tropical Storm Kujira’s cloud top temperatures and found strongest storms (yellow) were around Kujira’s center of circulation and in a band of thunderstorms in its western quadrant. 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 (red) Fahrenheit (minus 56.6. degrees Celsius) surrounded the center. Credit: NASA/NRL

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

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.

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.

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 local weather forecasts, visit: www.weather.gov

By Rob Gutro
NASA’s Goddard Space Flight Center