Mitag – Northwestern Pacific Ocean

Sep. 30, 2019 – NASA Finds Typhoon Mitag’s Eye East of Taiwan

NASA’s Terra satellite captured an image of Typhoon Mitag’s cloud-filled eye, located east of Taiwan.

Terra image of Mitag
On Sept. 30, the MODIS instrument that flies aboard NASA’s Terra satellite provided a visible image of Typhoon Mitag just east of Taiwan. Credit: NASA Worldview

On Sept. 30, the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite provided a visible image of Mitag. The MODIS image showed the cyclone continues to produce strong thunderstorms around its cloud-filled eye. Mitag’s western quadrant had already spread clouds and precipitation over Taiwan. Powerful bands of thunderstorms were swirling into the low-level center from the eastern side of the storm.

On Sept. 30, warnings remain in effect for the Philippines as Mitag, known locally as Onyok, continues to move north and away from the country. Philippines warnings still in effect include wind signal #1 for the Luzon provinces of Batanes and Babuyan Islands.

At 5 a.m. EDT (0900 UTC), Typhoon Mitag had maximum sustained winds near 75 knots. It was located near 22.8 degrees north latitude and 123.0 degrees east longitude, about 161 nautical miles south-southeast of Taipei, Taiwan.

Mitag is moving north, close to the east coast of Taiwan and forecasters at the Joint Typhoon Warning Center noted that Mitag is at peak intensity. The storm is forecast to graze the east coast of China, south of Shanghai, and then turn northeast.

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

Hurricanes are the most powerful weather event 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: https://www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Narda – Eastern Pacific

Sep. 30, 2019 – NASA Finds Tropical Storm Narda Bringing Heavy Rainfall to Western Mexico

NASA’s Aqua satellite captured an image of Tropical Storm Narda along Mexico’s west coast in the Eastern Pacific Ocean. Satellite data revealed the potential for heavy rainfall within Narda, and warnings are in effect for portions of western Mexico.

Aqua image of Narda
On Sept. 29 the MODIS instrument that flies aboard NASA’s Aqua satellite provided a visible image of Tropical Storm Narda along Mexico’s western coast.  Credit: NASA Worldview

Narda formed as Tropical Depression 16E on Saturday, Sept. 28 and intensified into a tropical storm late in the day. When it became a tropical storm it was renamed “Narda.”

On Sept. 30, the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite provided a visible image of Narda. The MODIS image showed the cyclone continues to produce a large area of deep convection near and to the west of its center. Earlier in the day, at 5 a.m. EDT, infrared satellite data showed that Narda continued to produce very intense deep convection (strong thunderstorms) with cloud tops colder than minus 80 degrees Celsius (minus 112 degrees Fahrenheit). NASA research has shown that storms with cloud top temperatures that cold can produce heavy rainfall.

That heavy rainfall potential is incorporated into the forecast for Sept. 30 from NOAA’s National Hurricane Center (NHC). Narda is expected to produce the following rainfall accumulations through Tuesday: Nayarit, Sinaloa…Additional 3 to 6 inches, isolated storm totals 10 to 15 inches. Jalisco, Colima, Michoacan…Additional 1 to 3 inches, isolated storm totals 10 to 15 inches. Chihuahua…1 to 3 inches. Baja California Sur, Sonora…1 to 2 inches.

At 11 a.m. EDT (1500 UTC), a Tropical Storm Warning is in effect from San Blas to Guaymas, and Islas Marias, Mexico.

The center of Tropical Storm Narda was located near latitude 22.5 degrees north and longitude 106.4 degrees west. That’s about 50 miles (80 km) south of Mazatlan, Mexico. NHC said recent microwave data and surface observations from Mexico indicate that the center of Narda is located just offshore of the west coast of mainland Mexico, north of Islas Marias.

Narda is moving toward the northwest near 15 mph (24 kph), and this general motion is expected to continue with some decrease in forward speed during the next couple of days. Maximum sustained winds are near 40 mph (65 kph) with higher gusts. Some slight strengthening is possible today. Weakening should begin by Tuesday as Narda interacts with the mountains of western Mexico. Tropical storm-force winds extend outward up to 45 miles (75 km) from the center.  A wind gust to 44 mph (70 kph) was recently reported at San Blas, Mexico. The estimated minimum central pressure is 1000 millibars.

On the forecast track, the center of Narda will move over the Gulf of California near the coast of northwestern mainland Mexico through Tuesday, Oct. 1.

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

Hurricanes are the most powerful weather event 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: https://www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Lorenzo – Atlantic Ocean

Sep. 30, 2019 – NASA-NOAA’s Suomi NPP Analyzes Record-Setting Hurricane Lorenzo

Over the weekend of Sept. 28 and 29, Hurricane Lorenzo attained Category 5 strength briefly, becoming the strongest hurricane on record in the eastern-most Atlantic Ocean. Lorenzo has also attained and contributed to some other significant statistics. NASA-NOAA’s Suomi NPP satellite provided infrared data over two days provided forecasters with changes in the storm’s eye, powerful thunderstorms and gravity waves it was creating.

Suomi NPP image of Lorenzo
The Suomi NPP satellite passed over the eastern Atlantic Ocean on Sept. 29, after Lorenzo weakened back to a Category 4 hurricane. The eye was well defined and there were mesovorticies seen. The strength of the storm also was producing mesospheric gravity waves. Credit: NASA/NOAA/UWM-CIMSS, William Straka

Record Setting

On Saturday, Sept. 28, when Lorenzo attained Category 5 (Cat 5) strength on the Saffir-Simpson Hurricane Wind Scale it was in a place more than 600 miles east-northeast of the previous record Cat 5 storm. It also had the lowest air pressure east of 50 degrees west longitude when the pressure dropped to 925 millibars.

There have been 26 Category 5 storms since 1960 with Lorenzo being the latest. Over the past 3 years, six storms attained that level of intensity. The others include Dorian, Michael, Maria, Irma and Matthew. Earlier this year Dorian reached Category 5 strength, so this year joins only six other years that contained more than one Cat 5 storm since records began. Other years with more than one Cat 5 storm include 1932, 1933, 1961, 2005, 2007 and 2017.

NASA-NOAA’s Suomi NPP Satellite Views

The Suomi NPP satellite passed over the eastern Atlantic Ocean on Sept. 29, after Lorenzo’s peak when it weakened back to a Category 4 hurricane. The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided infrared data on Lorenzo.

Tropical cyclones are made of up hundreds of thunderstorms, and infrared data can show where the strongest storms are located. They can do that because infrared data provides temperature information, and the strongest thunderstorms that reach highest into the atmosphere have the coldest cloud top temperatures.

“As with other strong hurricanes, the eye was well defined along with mesovortices seen,” said William Straka III, a researcher who created some Suomi NPP images at the University of Wisconsin – Madison, Space Science and Engineering Center (SSEC), Cooperative Institute for Meteorological Satellite Studies (CIMSS). The strength of the storm also was producing mesospheric gravity waves. Straka said, “Something interesting to note is that the mesospheric gravity waves from Lorenzo could be seen up to 1,180 km (733 miles) away. This isn’t that unheard of, but still worth noting.”

Mesovortices are small-scale rotational features found in convective storms, such as found in the eyewall of tropical cyclones. They can be as big as tens of miles in diameter or smaller such as a mile or less, and can be immensely intense.

NOAA defines a gravity wave as a wave created by the action of gravity on density variations in the stratified atmosphere. A generic classification for lee waves, mountains waves, and many other waves that form in the atmosphere.

At 0300Z on  September 30 (11 p.m. EDT on Sept. 29), the National Hurricane Center or NHC Public advisory  stated that Hurricane Lorenzo had winds of 110 mph, making it just barely a Category 3 hurricane. Three hours later at 2 a.m. EDT (0600 UTC) on Sept. 30, Lorenzo had weakened to a Category 2 hurricane as wind had decreased to 105 mph. When NASA-NOAA’s Suomi NPP satellite passed over Lorenzo, it analyzed the storm again in infrared light. NPP imagery showed mesospheric gravity waves quite possibly due to the energy being released as the storm weakened. NPP also showed a cloud-filled eye with clouds expanding to the northern quadrant. Both of these observations support the NHC Forecast Discussion at 5 a.m. EDT (0900 UTC).

Suomi NPP Image of Lorenzo
On Sept. 30, NASA-NOAA’s Suomi NPP satellite imagery showed mesospheric gravity waves quite possibly due to the energy being released as the storm weakened. NPP also showed a cloud-filled eye with clouds expanding to the northern quadrant. Credit: NASA/NOAA/UWM-CIMSS, William Straka

Hurricane Lorenzo on Sept 30

On Sept. 30, 2019 at 8 a.m. EDT (1200 UTC), NOAA’s National Hurricane Center issued watches for the Azores Islands. The Azores is a self-governing region of Portugal. The Azores consist of nine inhabited islands. All of them are under a watch from Lorenzo.  NHC posted a Hurricane Watch for Flores, Corvo, Faial, Pico, Sao Jorge, Graciosa, Terceira, and a Tropical Storm Watch is in effect for Sao Miguel, Santa Maria.

At that time, the center of Hurricane Lorenzo was located near latitude 29.4 degrees north and longitude 42.9 degrees west.  Lorenzo is moving toward the north-northeast near 14 mph (20 kph). Maximum sustained winds are near 105 mph (165 kph) with higher gusts. Hurricane-force winds extend outward up to 90 miles (150 km) from the center and tropical-storm-force winds extend outward up to 255 miles (405 km). The estimated minimum central pressure is 957 millibars.

Lorenzo’s Track

On the forecast track, the center of Lorenzo is expected to pass near the western Azores early on Wednesday, Oct. 2. Some weakening is forecast over the next two day, but Lorenzo is forecast to remain a large and powerful hurricane while it passes near the Azores.

In addition to threatening the Azores, Lorenzo is having quite the impact in the North Atlantic, despite being in the Eastern North Atlantic. NHC said, “Large swells spreading across much of the northern Atlantic basin. These swells are likely to cause life-threatening surf and rip current conditions.”

Hurricanes are the most powerful weather event 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

19W – Northwestern Pacific Ocean

Sep. 27, 2019 – NASA-NOAA Satellite Sees Tropical Depression 19W Organizing

NASA-NOAA’s Suomi NPP satellite passed over the Northwestern Pacific Ocean and provided forecasters at the Joint Typhoon Warning Center with a view of Tropical Depression 19W’s structure that helped confirm it is now a depression.

Suomi NPP image of 19W
On Sept. 27, NASA-NOAA’s Suomi NPP satellite passed over newly developed Tropical Depression 19W in the Northwestern Pacific Ocean. The Philippines are seen to the far west of the storm in this image. Credit: NASA/NOAA/NRL

On Sept. 27, 2019, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a visible image of newly developed Tropical Depression 19W. The VIIRS image showed the storm had already developed some strong thunderstorms around its center with a band of strong storms feeding into the center from the southeast. The VIIRS imagery helped confirm that the storm is now a depression and appears to be strengthening toward tropical storm status.

On Sept. 27 at 5 a.m. EDT (0900 UTC), Tropical Depression 19W had maximum sustained winds near 25 knots (29 mph)/46 kph). 19W was centered near 14.4 degrees north latitude and 136.2 degrees east longitude. That puts the center approximately 908 nautical miles southeast of Kadena Air Base, Okinawa Island, Japan. The storm was moving to the west.

Forecasters at the Joint Typhoon Warning Center expect 19W will move west-northwest and strengthen, then turn north and move east of Taiwan.

Hurricanes are the most powerful weather event 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

Karen – Atlantic Ocean

Sep. 27, 2019 – NASA Satellite Finds Karen Holding onto Tropical Storm Status through Cloud Heights, Temperatures

NASA’s Terra Satellite provides a variety of data on tropical cyclones including cloud heights and cloud top temperatures. Terra examined those factors in Tropical Storm Karen in the North Atlantic Ocean and data showed Karen holding onto tropical storm status.

Terra image of Karen
On Sept. 26, the MODIS instrument that flies aboard NASA’s Terra provided an image of cloud top temperatures and heights of Tropical Storm Karen. Purple indicates the highest cloud tops with the coldest temperatures. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).

Tropical cyclones are made up of hundreds of thunderstorms. By analyzing the heights of thunderstorms and their cloud top temperatures, forecasters can tell if a storm is strengthening or weakening. The higher the cloud tops, the stronger the uplift in a storm. That rising air helps thunderstorms develop.  As storms go higher, it is an indication that the storm is strengthening. Conversely, if over a period of time, satellite data shows cloud tops falling and warming, it is an indication the storm is weakening because there’s not as strong an uplift or rising air in the storm.

On Sept. 26, the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite measured clouds heights and temperatures. The imagery showed the highest cloud tops, higher than 12,000 meters (7.65 miles) were located around the center of circulation.

Terra data also found that cloud top temperatures were as cold as or colder than 200 Kelvin (minus 99.6 degrees Fahrenheit/minus 73.1 degrees Celsius) in those storms. NASA research has shown that cloud top temperatures that cold have the capability to generate heavy rainfall.

NOAA’s National Hurricane Center or NHC said at 5 a.m. EDT (0900 UTC), the center of Tropical Storm Karen was located near latitude 28.3 degrees north and longitude 61.2 degrees west. Karen is moving toward the northeast at near 8 mph (13 kph). This general motion is forecast to continue this morning, but Karen is forecast to become nearly stationary by tonight or early Saturday. A westward motion is then anticipated by the end of the weekend. Maximum sustained winds are near 40 mph (65 kph) with higher gusts.

Karen is forecast to degenerate into a remnant low by Saturday.

The Terra satellite cloud height and temperature data was provided by NASA’s Worldview product at NASA’s Goddard Space Flight Center, Greenbelt, Md.

Hurricanes are the most powerful weather event 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

Lorenzo – Atlantic Ocean

Sep. 27, 2019 – NASA Data Stares into the Eye of Powerful Hurricane Lorenzo

Satellite data has confirmed that Lorenzo is a major hurricane in the eastern North Atlantic Ocean with an impressive structure. NASA’s Terra Satellite provided a visible image of Lorenzo that revealed a clear eye and a solid structure of thunderstorms around the eye.

Terra image of Lorenzo
On Sept. 26, the MODIS instrument that flies aboard NASA’s Terra provided a visible image of Hurricane Lorenzo moving through the eastern North Atlantic Ocean. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).

On Sept. 26, the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite provided a visible image of Lorenzo as a major hurricane. The image and other satellite images showed a well-defined eye. The MODIS image revealed powerful thunderstorms around the eyewall, extending high into the troposphere. The circular shape of the storm indicated an organized and powerful storm.

At 5 a.m. EDT (0900 UTC), on Sept. 27 the center of Hurricane Lorenzo was located near latitude 18.6 degrees north and longitude 42.1 degrees west. Lorenzo is moving toward the north-northwest near 14 mph (22 km/h), and this general motion is forecast to continue today. A turn toward the north is expected on Saturday, followed by a turn toward the northeast on Sunday. Maximum sustained winds remain near 145 mph (230 kph) with higher gusts. Lorenzo is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some fluctuations in strength are possible today. Slow weakening is forecast to begin by the weekend.

Lorenzo is a large hurricane. Hurricane-force winds extend outward up to 45 miles (75 km) from the center and tropical-storm-force winds extend outward up to 265 miles (425 km).

Lorenzo, as a Category 4 hurricane has a long reach with ocean swells. Swells generated by Lorenzo are affecting portions of the northeastern coast of South America and will affect portions of the Windward Islands beginning today.

The estimated minimum central pressure is 937 mb (27.67 inches).

Hurricanes are the most powerful weather event 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

Karen – Atlantic Ocean

Sep. 26, 2019 – NASA Finds Tropical Storm Karen’s Strength on Western Side

NASA’s Terra satellite captured an image of Tropical Storm Karen on Sept. 26 and found the strongest thunderstorms west of center.

Terra image of Karen
On Sept. 26 at 1:30 p.m. EDT, the MODIS instrument that flies aboard NASA’s Terra satellite captured this visible image of Karen, that showed a cluster of storms west of center and the storm appeared somewhat elongated. Credit: NASA Worldview

On Sept. 26 at 1:30 p.m. EDT on Sept. 26, the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite provided a visible image of Karen. The image showed the Karen has been maintaining a cluster of developing thunderstorms and convection to the west of center. NOAA’s National Hurricane Center noted that visible satellite images, such as the one from NASA’s Terra satellite and wind data from NOAA buoy 40149 to the northeast, suggest that the low-level circulation is becoming elongated. When a storm becomes elongated, it’s a sign of weakening.

The shape of the storm is a clue to forecasters that a storm is either strengthening or weakening. If a storm takes on a more rounded shape it is getting more organized and strengthening. Conversely, if it becomes less rounded or elongated, like Karen, it is a sign the storm is weakening.

At 11 a.m. EDT (1500 UTC), the center of Tropical Storm Karen was located near latitude 26.6 degrees north and longitude 63.3 degrees west. Karen was centered about 405 miles (650 km) south-southeast of Bermuda. Karen is moving toward the north-northeast near 14 mph (22 kph), and this motion is expected to continue with a decrease in forward speed through this evening.  Karen is then forecast to make a slow clockwise loop, ultimately moving westward by early Sunday.

Satellite-derived wind data indicate that maximum sustained winds are near 45 mph (75 kph) with higher gusts. The estimated minimum central pressure is 1004 millibars.

Weakening is forecast by the weekend, and Karen is expected to become a remnant low by Sunday, Sept. 29.

Hurricanes are the most powerful weather event 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: https://www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Lorenzo – Atlantic Ocean

Sep. 26, 2019 – Lorenzo Now a More Organized and Powerful Hurricane on NASA Satellite Imagery

NASA-NOAA’s Suomi NPP satellite provided a full visible image of a strengthening Hurricane Lorenzo in the eastern North Atlantic Ocean. On Sept. 26, Lorenzo attained status as a major hurricane.

Suomi NPP image of Lorenzo
On Sept. 25, the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite provided a visible image of Hurricane Lorenzo in the eastern North Atlantic Ocean. The African continent is east (right) in the image. Credit: NASA/NRL

A major hurricane is one that is a Category 3 or higher on the Saffir-Simpson Hurricane Wind Scale.

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a visible image of the storm on Sept. 25. The VIIRS image showed powerful thunderstorms circling the center of Lorenzo with thick bands of thunderstorms wrapping into the low-level center from the south and east of center. The satellite imagery revealed that Lorenzo was getting better organized as it was strengthening. By 11 p.m. EDT, infrared imagery showed a small eye had been appearing intermittently.

The shape of the storm is a clue to forecasters that a storm is either strengthening or weakening. If a storm takes on a more rounded shape it is getting more organized and strengthening. Conversely, if it becomes less rounded or elongated, it is a sign the storm is weakening.

On Sept. 26, shortly after 5 a.m. EDT (0900 UTC), the National Hurricane Center (NHC) said Lorenzo’s eye quickly and drastically became more apparent in conventional satellite imagery. The slightly ragged but clearing eye of the hurricane is surrounded by very cold cloud tops, and it has become clear that Lorenzo is rapidly intensifying.

By 6 a.m. EDT (1000 UTC), the center of Hurricane Lorenzo had maximum sustained winds have rapidly increased to near 125 mph (205 kph) with higher gusts.  Lorenzo is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale.

Lorenzo was located near latitude 15.2 degrees north and longitude 39.3 degrees west. That puts Lorenzo’s eye about 995 miles (1,600 km) west of the southernmost Cabo Verde Islands.

The hurricane is moving toward the west-northwest near 15 mph (24 kph). Lorenzo is forecast to turn toward the northwest and begin moving at a slightly slower speed later today. A turn toward the north is then anticipated on Saturday, Sept. 28.

Additional strengthening is possible today. Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 205 miles (335 km). The estimated minimum central pressure is 955 millibars.

Hurricanes are the most powerful weather event 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

Karen – Atlantic Ocean

Sep. 25, 2019 – NASA Finds Tropical Storm Karen Bringing Heavy Rain to Puerto Rico

Tropical Storm Karen has crossed over Puerto Rico and into the western Atlantic Ocean. Early on Sept. 25 when Global Precipitation Measurement mission or GPM core satellite passed overhead, the satellite found heavy rain occurring over the territory.

GPM image of Karen
The GPM’s core satellite passed over Tropical Storm Karen on Sept. 25 at 0316 UTC (Sept. 24 at 11:16 p.m. EDT ). GPM found heavy rain falling at a rate of greater than 1.6 inches (40 millimeters) southwest of Karen’s center over the Atlantic Ocean and just north of central Puerto Rico. Heavy rain was also (dark blue and orange) falling a more than 1 inch (25 mm) per hour over Puerto Rico and extended far to the north of Karen’s center into the Atlantic. Credit: NASA/NRL

The GPM’s core satellite passed over Tropical Storm Karen on Sept. 25 at 0316 UTC (Sept. 24 at 11:16 p.m. EDT). GPM found heavy rain falling at a rate greater than 1.6 inches (40 millimeters) southwest of Karen’s center over the Atlantic Ocean and just north of central Puerto Rico. Heavy rain was also falling at more than 1 inch (25 mm) per hour over much of Puerto Rico and extended far to the north of Karen’s center into the Atlantic.

Forecasters at NOAA’s National Hurricane Center or NHC incorporate the rainfall data into their forecasts. At 11 a.m. EDT (1500 UTC), NHC noted “Karen is expected to produce additional rainfall accumulations of 1 to 2 inches across Puerto Rico and the Virgin Islands, with isolated storm totals of 8 inches.”

The center of Tropical Storm Karen was located near latitude 21.7 degrees north and longitude 64.9 degrees west. Karen’s center had moved further away from Puerto Rico since the GPM image was collected and was located about 240 miles (385 km) north-northwest of San Juan, Puerto Rico.

Karen was moving toward the north near 15 mph (24 kph). Maximum sustained winds are near 45 mph (75 kph) with higher gusts. Some strengthening is forecast during the next couple of days. Tropical-storm-force winds extend outward up to 70 miles (110 km) from the center. The estimated minimum central pressure is 1003 millibars.

NHC said, “A north-northeastward to northeastward motion with a decrease in forward speed is expected through early Friday.  Karen is then expected to slow down and make a clockwise loop over the southwestern Atlantic into the weekend.”

Hurricanes are the most powerful weather event 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.

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

For updated forecasts on Karen from NHC, Visit: www.nhc.noaa.gov

For local forecasts from the National Weather Service in Puerto Rico, Visit: https://www.weather.gov/sju/

By Rob Gutro
NASA’s Goddard Space Flight Center

Lorenzo – Atlantic Ocean

Sep. 25, 2019 – NASA-NOAA Satellite Sees Hurricane Lorenzo Strengthening

Dropping cloud top temperatures from NASA-NOAA’s Suomi NPP satellite indicated Hurricane Lorenzo was getting stronger in the North Atlantic Ocean.

Suomi NPP image of Lorenzo
NASA-NOAA’s Suomi NPP satellite passed over Hurricane Lorenzo in the North Atlantic Ocean and the VIIRS instrument aboard captured this image of the storm on Sept. 25 at 0312 UTC (Sept. 24 at 11:12 p.m. EDT). A large area (yellow) of powerful thunderstorms circled the eye where cloud top temperatures were as cold as minus 121 Fahrenheit (minus 85 degrees Celsius). Credit: NASA/NRL

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided an infrared image of the storm. Infrared imagery reveals cloud top temperatures, and the higher the cloud top, the colder it is, and the stronger the storm. On Sept. 25 at 0312 UTC (Sept. 24 at 11:12 p.m. EDT) a large area of powerful thunderstorms circled the eye where cloud top temperatures were as cold as minus 121 Fahrenheit (minus 85 degrees Celsius). NOAA’s National Hurricane Center (NHC) forecasters cited that data in their Discussion at that time.

NASA research has shown that storms with cloud tops that cold have been found to generate heavy rainfall.

Later in the day, at 11 a.m. EDT (1500 UTC), the center of Hurricane Lorenzo was located near latitude 14.1 degrees north and longitude 35.1 degrees west. That is about 715 miles (1,155 km) west of the southernmost Cabo Verde islands.  Lorenzo is moving toward the west-northwest near 17 mph (28 kph), and this motion is expected to continue through Thursday.

A turn toward the northwest is expected late Thursday. Maximum sustained winds have increased to near 85 mph (140 kph) with higher gusts.  Additional strengthening is forecast during the next couple of days, and Lorenzo is forecast to become a major hurricane by Thursday [Sept. 26]. The estimated minimum central pressure is 983 millibars.

Hurricanes are the most powerful weather event 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