Lingling – Northwestern Pacific Ocean

Sep. 03, 2019 – NASA Infrared Eye Analyzes Typhoon Lingling   

The storm that became Typhoon Lingling strengthened very quickly in the Northwestern Pacific Ocean and infrared imagery from NASA revealed the powerful thunderstorms fueling that intensification.

Terra image of Lingling
On Sept. 3 at 12:05 p.m. EDT (1405 UTC) the MODIS instrument that flies aboard NASA’s Terra satellite showed areas northeast and southeast of Typhoon Lingling’s center where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). Credit: NASA/NRL

Lingling formed on Sept. 2 as Tropical Depression 15W and strengthened quickly into a tropical storm and then a typhoon.  Although Lingling is to the northeast of Luzon, northern Philippines, there are still some warning signals in effect on Sept. 3. Tropical cyclone wind signal #1 is in effect over the Luzon province of Batanes.

On Sept. 3 at 12:05 p.m. EDT (1405 UTC), the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite used infrared light to analyze the strength of storms within the typhoon. NASA researches these storms to determine how they rapidly intensify, develop and behave.

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.

MODIS found those strongest storms were northeast and southeast of the center of circulation where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). NASA research has found that cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

At 11 a.m. EDT (1500 UTC), the Joint Typhoon Warning Center or JTWC said that Typhoon Lingling, known locally in the Philippines as Liwayway was located near 21.4 degrees north latitude and 124.2 degrees east longitude. That is 364 nautical miles southwest of Kadena Air Base, Okinawa, Japan. Lingling was moving to the north and had maximum sustained winds near 65 knots (75 mph/120.3 kph).

JTWC forecasters said that Lingling is moving north and is expected to intensify to 100 knots (115 mph/185 kph) upon passing east of Taiwan. The system will then weaken on approach to the Korean peninsula, but still be at typhoon strength.

By Rob Gutro
NASA’s Goddard Space Flight Center

Juliette – Eastern Pacific Ocean

Sep. 03, 2019 – Major Hurricane Juliette’s Emerging Eye Spotted in NASA Satellite Imagery

NASA’s Aqua satellite passed over the Eastern Pacific Ocean and provided an image of Hurricane Juliette as its eye began to emerge. Juliette has grown into a major hurricane, about 450 miles southwest of the southern tip of Baja California, Mexico.

Aqua image of Juliette
On Sept. 2, 2019 at 4:25 p.m. EDT (2025 UTC) the MODIS instrument aboard NASA’s Aqua satellite provided a visible image of Hurricane Juliette in the Eastern Pacific Ocean as its eye began to show. Credit: NASA/NRL

Juliette developed on Sunday, Sept 1 around 5 a.m. EDT (0900 UTC) as a tropical storm. By 5 p.m. EDT on Sept. 2, the storm had strengthened into a hurricane.

On Sept. 2, 2019 at 4:25 p.m. EDT (2025 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite provided a visible image of Hurricane Juliette that revealed its emerging eye around a thick tight circle of powerful thunderstorms. Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 125 miles (205 km).

NASA researches hurricanes to better understand their behavior, and provides data to forecasters at NOAA’s NHC or National Hurricane Center to assist in their forecasting.

On Sept. 3 at 11 a.m. EDT (1500 UTC), NOAA’s National Hurricane Center said the eye of Hurricane Juliette was located near latitude 18.4 degrees north and longitude 115.0 degrees west. That’s about 455 miles (730 km) southwest of the southern tip of Baja California, Mexico. Juliette is moving toward the northwest near 8 mph (13 kph), and a northwest to west-northwest motion is expected through Friday. Maximum sustained winds have increased to near 125 mph (205 kph) with higher gusts.  Juliette is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. The estimated minimum central pressure is 953 millibars based on satellite estimates and data from the Mexican Navy station on Clarion Island.

NHC said. “Some strengthening is possible today, with weakening forecast to begin by late Wednesday and continuing through Friday.”

For updated forecasts, visit NOAA’s NHC: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

TD7 – Atlantic Ocean

Sep. 03, 2019 – NASA Infrared Data Reveals Rainmaking Potential in Tropical Depression 7

 Another Atlantic Ocean basin depression formed while Hurricane Dorian is still wreaking havoc on the Bahamas and affecting the southeastern U.S. Infrared imagery from NASA’s Aqua satellite shows that Tropical Depression 7 in the western Gulf of Mexico has developed powerful thunderstorms with heavy rain capabilities. That potential for heavy rainfall includes southern Texas and northeastern Mexico.

MODIS image of TD7
On Sept. 3 at 4:30 a.m. EDT (0830 UTC) the MODIS instrument that flies aboard NASA’s Aqua satellite showed strongest storms (red) in fragmented thunderstorms around the center of Tropical Depression 7 in the western Gulf of Mexico. There, cloud top temperatures were as cold as minus 70 degrees Fahrenheit (minus 56.6 Celsius). Credit: NASA/NRL

NASA conducts research on tropical cyclones and provides various data to forecasters at NOAA’s National Hurricane Center (NHC) to consider in their forecasts.

NASA’s Aqua satellite used infrared light to analyze the strength of storms in Tropical Depression 7 and found strongest storms in fragmented bands of thunderstorms north and south of the center. The westernmost extent of those strong storms were already affecting the extreme northeastern coast of Mexico. Infrared data provides temperature information, and the strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures.

On Sept. 3 at 4:30 a.m. EDT (0830 UTC) the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite found strongest thunderstorms had cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6 Celsius). Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

The NHC said the system is expected to produce the following rainfall totals through Friday:

In northeastern Mexico, 6 to 12 inches of rainfall is possible with isolated totals to 15 inches, highest in the Sierra Madre Oriental of Tamaulipas and Nuevo Leon. This rainfall may cause life-threatening mudslides and flash floods. In south Texas and the lower Texas Coast, 2 to 4 inches are possible with isolated amounts as high as 6 inches.

Tropical Depression 7 (TD7) formed around 5 a.m. EDT today, Sept. 3, 2019 and NHC posted a Tropical Storm Warning from La Pesca to Barra El Mezquital, Mexico.

NHC’s advisory at 11 a.m. EDT (1500 UTC) on Sept. 3 noted that the center of Tropical Depression Seven (TD7) was located near latitude 23.6 degrees north and longitude 94.9 degrees west.  The depression is moving toward the west near 7 mph (11 kph), and this motion is expected to continue today.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Slow strengthening is forecast before the system moves inland, and the depression is expected to become a tropical storm by Wednesday. The estimated minimum central pressure is 1004 millibars.

NHC forecasters said a motion toward the west-northwest is forecast tonight and Wednesday.  This motion could bring the system near or over the coast of northeastern Mexico late Wednesday.

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

By Rob Gutro
NASA’s Goddard Space Flight Center

Dorian – Atlantic Ocean

Sep. 03, 2019 – NASA’s IMERG Estimates Hurricane Dorian’s Rain

In the early hours of Tuesday, September 3, Hurricane Dorian had been stationary over the island of Grand Bahama for 18 hours, most of the time as a category 5 hurricane. Storm-total rain accumulation over parts of Grand Bahama and Abaco Islands have exceeded 24 inches according to NASA satellite-based estimates.

IMERG data on rainfall from Dorian
NASA’s IMERG storm-total rain accumulation over parts of Grand Bahama and Abaco islands have exceeded 24 inches according to NASA satellite-based estimates. The graphic also shows the distance that tropical-storm force (39 mph) winds extend from Hurricane Dorian’s low-pressure center, as reported by the National Hurricane Center. The symbols H and TS represent a hurricane of various Saffir-Simpson categories or a tropical storm, respectively. Image Credit: NASA Goddard

On early Tuesday morning, Dorian’s central pressure had risen and its wind intensity had dropped to category 4 on the Saffir-Simpson scale.  In addition, Dorian had experienced an eyewall replacement cycle on September 2, so by Tuesday morning Sept. 3, the geographic extent of its tropical-storm-force winds had expanded.

These rain estimates come from the NASA IMERG algorithm, which combines observations from a fleet of satellites, in near-realtime, to provide global estimates of precipitation every 30 minutes. The storm-total rainfall at a particular location varies with the forward speed of the hurricane, with the size of the hurricane’s wind field, and with how vigorous the updrafts are inside of the hurricane’s eyewall.

IMERG, or the Integrated Multi-satellitE Retrievals for GPM (IMERG) data product is generated by NASA’s Precipitation Processing System every half hour with a 6 hour latency from the time of data acquisition. It is produced using data from the satellites in the GPM or Global Precipitation Measurement mission constellation of satellites, and is calibrated with measurements from the GPM Core Observatory as well as rain gauge networks around the world.

IMERG is an example of the research role that NASA has in hurricanes  – developing observational tools and building computer models to better understand the behavior of tropical cyclones. NASA’s research data is utilized by NOAA’s National Hurricane Center (NHC) to enhance their forecasts.

On Tuesday, September 3, 2019, at 8 a.m. EDT (1200 UTC), NHC reported at the eye of Hurricane Dorian was located by reconnaissance aircraft and NOAA Doppler radar near latitude 27.1 degrees North and longitude 78.4 degrees West. NHC said Dorian is beginning to move northwestward at about 1 mph (2 kph), and a slightly faster motion toward the northwest or north-northwest is expected later today and tonight.

At present maximum sustained winds are near 120 mph (195 kph) with higher gusts.  Dorian is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale.  Dorian is expected to remain a powerful hurricane during the next couple of days. Hurricane-force winds extend outward up to 45 miles (75 km) from the center, and tropical-storm-force winds extend outward up to 160 miles (260 km). The latest minimum central pressure reported by reconnaissance aircraft is 952 mb (28.11 inches).

NHC forecasts a turn toward the north by Wednesday evening, followed by a turn to the north-northeast Thursday morning.  On this track, the core of extremely dangerous Hurricane Dorian will gradually move north of Grand Bahama Island through this evening. The hurricane will then move dangerously close to the Florida east coast late today through Wednesday evening, very near the Georgia and South Carolina coasts Wednesday night and Thursday, and near or over the North Carolina coast late Thursday.

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

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

By Owen Kelly / with NOAA’s NHC Update
NASA’s Goddard Space Flight Center

Dorian – Atlantic Ocean

Sep. 02, 2019 – Update #2  4:00 pm EDT – NASA Overhead as Dangerous Hurricane Dorian Takes Aim at Grand Bahamas

Dangerous Hurricane Dorian has weakened slightly and is now a Category 4 storm as it continues to spin over the Bahamas.  Dorian has slowed to a crawl in terms of speed of movement only moving at west-northwest at about 1 mph (2 km/h).  This means that the Bahamas will continue to get lashed by this monstrous storm and the amount of rainfall totals for the area continue to grow. The National Hurricane Center (NHC) has reported that the eye of the hurricane has begun to wobble a bit over Grand Bahama Island.  It is expected to stay over the island for much of the day causing extreme destruction.

Astronaut Christina Koch captured this image from the International Space Station earlier this morning.

Image of Dorian from ISS
Astronaut Christine Koch of the International Space Station captured this image of Hurricane Dorian outside the ISS windows the morning of Sep. 02, 2019. Credit: NASA

NOAA-20 observed Hurricane Dorian at 2:13 am EDT (0613 UTC) on the extreme western edge of the scan (image below). It provided an image of the classic presentation of a strong hurricane, with a nearly symmetrical circulation. Tropospheric gravity waves coming off the convection surrounding the central circulation could be seen in the infrared imagery. The Day Night Band imagery (second image below) showed the general structure of the storm with some lightning streaks. In addition, some possible mesospheric gravity waves seemed to be near the circulation center.

NOAA-20 image of Hurricane Dorian
NOAA-20 observed Hurricane Dorian at 2:13 am EDT (0613 UTC) on the extreme western edge of the scan. Credit: NASA/NOAA/UWM-SSEC-CIMSS/William Straka III
NOAA-20 day night band image of Dorian
The Day Night Band on the NOAA-20 satellite showed the general structure of the storm with some lightning streaks. In addition, some possible mesospheric gravity waves seemed to be near the circulation center. Also the lights from the capital city of Nassau could be seen scattering light through the clouds, which were relatively thinner as compared to areas nearer the eye of the storm. Credit: NASA/NOAA/UWM-SSEC-CIMSS/William Straka III

NOAA/NASA’s Suomi NPP satellite flew over Dorian about 50 minutes later at 3:03 am EDT (0703 UTC) and it had the most ideal position for observing the eye of Dorian (image below) . Suomi NPP’s infrared imagery showed the classic presentation of a strong hurricane, though slightly rotated. The lights from the capital city of Nassau could also be seen through the clouds.

Suomi NPP Image of Dorian
NOAA/NASA’s Suomi NPP satellite flew over Dorian about 50 minutes later at 3:03 am EDT (0703 UTC) and it had the most ideal position for observing the eye of Dorian. Suomi NPP’s infrared imagery showed the classic presentation of a strong hurricane, though slightly rotated. Credit: NASA/NOAA/UWM-SSEC-CIMSS/William Straka III
Suomi NPP image of Dorian
NASA NOAA’s Suomi NPP satellite image provided a very clear, very detailed image of Dorian’s eye in this image taken on Sep. 02, 2019 at 2:13 am EDT. Credit: NASA/NOAA/UWM-SSEC-CIMSS/William Straka III

The MiRS rain rate product (image below) on NASA NOAA’s Suomi NPP satellite also showed the rain wrapping into the circulation center.

Suomi NPP image of Dorian showing rainfall rates
The MiRS instrument on NASA NOAA’s Suomi-NPP satellite shows rainfall rates within the storm as well as showing the rain wrapping around the eye of the hurricane. Credit: NASA/NOAA/UWM-SSEC-CIMSS/William Straka III

As of the NHC’s update at Dorian is producing maximum sustained winds of 145 mph (230 km/h) with wind gusts of 190 mph (305 km/h).  The storm is located latitude 26.8N and longitude 78.4W which is about 25 miles (40 km) northeast of Freeport, Grand Bahama Island and about 105 miles (170 km) east of West Palm Beach, FL. The minimum central pressure is 940 Mb.

For the latest information on Dorian, visit: https://www.nhc.noaa.gov

By Lynn Jenner
NASA Goddard Space Flight Center

Dorian – Atlantic Ocean

Sep. 02, 2019- Update #1 – 9:00am EDT – Destructive Dorian Lashing Grand Bahama Island

Hurricane Dorian is breaking records over the Bahamas as the most destructive hurricane to ever hit the Bahama Islands. Catastrophic winds with gusts over 200 mph are smashing through the islands leaving devastation in their wake. Storm surge of 18 to 23 feet above normal tide levels with higher destructive waves are expected throughout the storm’s passing.

On Dorian’s current track and speed of movement, the core of extremely dangerous Hurricane Dorian will continue to pound Grand Bahama Island through much of today and tonight. The hurricane will move dangerously close to the Florida east coast tonight through Wednesday evening.

NASA’s Global Precipitation Measurement mission (GPM) was on hand to measure the amount of rainfall that the Bahama Islands are experiencing now.

GPM imagea of Dorian
These rain estimates come from the NASA IMERG algorithm, which combines observations from a fleet of satellites, in near-realtime, to provide global estimates of precipitation every 30 minutes. The storm-total rainfall at a particular location varies with the forward speed of the hurricane, with the size of the hurricane’s wind field, and with how vigorous the updrafts are inside of the hurricane’s eyewall. The graphic also shows the distance that tropical-storm force (39 mph) winds extend from Hurricane Dorian’s low-pressure center, as reported by the National Hurricane Center. The geographic extent of the tropical-storm strength winds has expanded throughout Dorian’s lifetime. The symbols H and TS represent a hurricane of various Saffir-Simpson categories or a tropical storm, respectively. Visualization by NASA Goddard.

On Monday morning, September 2, Hurricane Dorian was over the island of Grand Bahama as a category 5 storm. As has been the case for the past several days, Dorian’s inner core continues to produce 6 to 14 inches of rain accumulation. Hurricane Dorian’s forward motion has slowed to walking pace, so future updates to this rain-accumulation map may show greater accumulation over Grand Bahama than elsewhere along the storm’s path.

AIRS image of Dorian
On Sep. 01, 2019, at 2:05 am EDT (0705 UTC) the Aqua satellite using the AIRS instrument analyzed temperatures within Hurricane Dorian. Cloud top temperatures within Dorian were as cold as or colder than minus 50 degrees Fahrenheit (minus 45.5 degrees Celsius). Infrared data provides temperature information, and the strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures. In this image, the amount of purple (coldest temperatures) surrounding the eye shows the huge and massive number of thunderstorms that continue to circle around the still very well-defined eye. Credit: NASA JPL/Heidar Thrastarson

NASA’s Aqua satellite captured this image of Dorian at 2:05 am EDT (0705 UTC) using its AIRS (Atmospheric Infrared Sounder) instrument analyzed temperatures within Hurricane Dorian. Cloud top temperatures within Dorian were as cold as or colder than minus 50 degrees Fahrenheit (minus 45.5 degrees Celsius). Infrared data provides temperature information, and the strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures. In this image, the amount of purple (coldest temperatures) surrounding the eye shows the huge and massive number of thunderstorms that continue to circle around the still very well-defined eye.

At present Dorian is located at latitude 26.7N and longitude 78.3W which is about 30 miles (50 km) east-northeast of Freeport, Grand Bahama Island and about 115 miles (185 km) east of West Palm Beach, FL.  Maximum sustained winds are now 165 mph (270 km/h) down from a high of 185 mph (298 km/h).  The present movement of storm is west at 1 mph (2 km/h) leaving the storm basically parked in location for hours. The minimum central pressure inside the storm is 916 mb.

For more updates on this storm, visit: https://www.nhc.noaa.gov

By Lynn Jenner
NASA Goddard Space Flight Center

 

Dorian – Atlantic Ocean

Sep. 01, 2019 – Update #3 – 3:00 pm – Devastating Category 5 Hurricane Dorian Makes a Direct Hit on Abaco Islands

The eye of Category 5  Hurricane Dorian was directly over the Abaco Islands as of the National Hurricane Center’s (NHC) 2:00 pm EDT advisory and is now heading towards Grand Bahama Island. The hurricane is located about 185 miles (295 km) east of West Palm Beach, FL. Maximum sustained winds are 185 mph (295 km/h) with gusts over 200 mph. Dorian is moving west at 7 mph.  The central pressure is 911 Mb which continues to lower meaning the storm continues to intensify. This is the fifth Category 5 hurricane sustained in the last five years.

Suomi NPP image of Dorian
Suomi NPP image of Hurricane Dorian showing its well-defined eye as it passed over Dorian at 3:20 am EDT (0720 UTC). Credit: NASA/NOAA/UWM-SSEC-CIMSS/William Straka III

NASA and NOAA satellites flew over the storm after the NHC’s 2:00 am EDT (0600Z) advisory each highlighting unique features within the storm. At 3:20 am EDT (0720 UTC) NASA’s Suomi NPP satellite caught Dorian (above) on the east side of the scan in the Day Night band but due to the angle did not yield as many features due to noise at the edge of the scan, however, the well-defined eye can still be seen along with the tropospheric convective gravity waves flowing away from the storm.

NOAA-20’s VIIRS instrument provides this image in its Day Night band of Hurricane Dorian at 2:30 am EDT on Sep. 01, 2019. Credit: NASA/NOAA/UWM-SSEC-CIMSS/William Straka III

A slower westward motion should continue for the next day or two, followed by a gradual turn toward the northwest. On this track, the core of
extremely dangerous Hurricane Dorian will continue to pound Great Abaco today and the move near or over Grand Bahama Island tonight and Monday. The hurricane should move closer to the Florida east coast late Monday through Tuesday night.

Hurricane-force winds extend outward up to 45 miles (75 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km). The eye of the hurricane is now 25 nautical miles across.

For continuous coverage visit: https://www.nhc.noaa.gov

By Lynn Jenner
NASA Goddard Space Flight Center

Dorian – Atlantic Ocean

Sep. 01, 2019 – Update #2 – 10:35 am EDT – Dorian Intensifying Again With Winds Picking Up Speed

The National Hurricane Center (NHC) put out another update advisory at 9:30 am EDT on Sep. 01, 2019 as Hurricane Dorian intensified again.

Data from an Air Force Reserve Hurricane Hunter aircraft indicate
that Dorian has continued to intensify, and now has maximum
sustained winds near 175 mph (280 km/h) and wind gusts over 200 mph.  Storm surge of 15 to 20 feet above normal tides with higher destructive waves.  There is a minimum central pressure of 922 mb (27.23 inches).

The eyewall of catastrophic Hurricane Dorian is currently reaching
the Abaco Islands. This is a life-threatening situation. Residents
there should take immediate shelter.  The NHC urges: “Do not venture into the eye if it passes over your location. These hazards will cause extreme destruction in the affected areas. and will continue for several hours.”

The NOAA-20 satellite observed Dorian’s continued intensification in this satellite image which was captured on Sep. 01, 2019 at 2:30 am EDT.

GPM image of Dorian
NOAA-20 flew over Dorian not quite looking straight down. As with previous nights, the infrared imagery continued to show convective gravity waves and a well-defined eye. However, unlike previous nights, the cirrus blowoff was not present. Rather it was replaced by the classic “buzzsaw” type cloud commonly seen in very intense tropical storms. This Day Night Band imagery continues to show the structure of Dorian quite well along with mesospheric gravity waves being flung far away from the storm as well as a lone lightning streak well on the southern part of the storm. Credit: NASA/NOAA/UWM-SSEC-CIMSS/William Straka III

For continuing coverage of the storm visit: https://www.nhc.noaa.gov

By Lynn Jenner
NASA Goddard Space Flight Center

Dorian – Atlantic Ocean

Sept. 01, 2019 – Update #1 – NASA Satellites Monitor Progress as Hurricane Dorian Reaches Dangerous Category 5 Status

The National Hurricane Center’s (NHC) 8:00 am EDT advisory reports that Hurricane Dorian has reached Category 5 status on the Saffir-Simpson Hurricane Wind scale. Data from an Air Force Hurricane Hunter plane which just penetrated the eye of Dorian indicate that the maximum sustained winds have increased to near 160 mph (260 km/h) with higher gusts. Devastating hurricane conditions are expected in the Abacos Islands very soon and these conditions will spread across Grand Bahama Island later today.

GPM image of Dorian
As of Saturday, August 31, Hurricane Dorian’s (still a Category 4 storm at the time) rain field had changed. During its early days near Puerto Rico, Dorian’s inner-core rain rate had peaked once every 24 hours, but during the most recent two days, Dorian’s rain rate has been persistently heavy. Heavy precipitation under the eyewall suggests that a great deal of energy is being released in the atmosphere, which is the fuel that allows a hurricane to sustain or increase its wind intensity. The graphic also shows the distance that tropical-storm force (39 mph) winds extend from Hurricane Dorian’s low-pressure center, as reported by the National Hurricane Center. The symbols H and TS represent a hurricane of various Saffir-Simpson categories or a tropical storm, respectively. Visualization by NASA Goddard.

As of Saturday, August 31, Hurricane Dorian’s rain field had changed. During its early days near Puerto Rico, Dorian’s inner-core rain rate had peaked once every 24 hours, but during the most recent two days, Dorian’s rain rate has been persistently heavy. Heavy precipitation under the eyewall suggests that a great deal of energy is being released in the atmosphere,
which is the fuel that allows a hurricane to sustain or increase its wind intensity.

These rain estimates come from the Global Precipitation Measurement mission (GPM)’s NASA IMERG algorithm, which combines observations from a fleet of satellites, in near-realtime, to provide global estimates of precipitation every 30 minutes. The storm-total rainfall at a particular location varies with the forward speed of the hurricane, with the size of the hurricane’s wind field, and with how vigorous the updrafts are inside of the hurricane’s eyewall.

NASA’s Aqua satellite also was providing scientists with data about the storm when it passed overhead on Aug. 31, 2019.

AIRS image of Dorian on Aug. 31
On Aug. 31 at 2:17a.m. EDT (0617 UTC), the AIRS instrument aboard NASA’s Aqua satellite analyzed cloud top temperatures of Tropical Storm Dorian in infrared light. AIRS found coldest cloud top temperatures (purple) of strongest thunderstorms were as cold as or colder than minus 63 degrees Fahrenheit (minus 53 degrees Celsius).  The area of very cold temperatures is extremely large around the eye indicating greater intensity. Credit: NASA JPL/Heidar Thrastarson

This image, captured by NASA’s Aqua satellite at 2:17 am EDT the morning of the 31st, shows incredibly cold temperatures in the cloudtops of the storm.  The area of purple, the coldest temperatures, extends out widely from the very distinct eye of the hurricane. The stronger the storms, the higher they extend into the troposphere, and the colder the cloud temperatures become so the AIRS instrument gives a good picture to scientists of the strength of the storm.

The NHC has reported that hurricane-force winds extend outward up to 30 miles (45 km) from the center, and tropical-storm-force winds extend outward up to 105 miles (165 km). Elbow Cay in the Abaco Islands just reported winds of 35 mph (56 km/h).  The minimum central pressure just measured by an Air Force plane has dropped to 927 mb (27.37 inches).

The following information is directly from the National Hurricane Center’s 8:00 am EDT advisory:

“A Hurricane Warning is in effect for…* Northwestern Bahamas excluding Andros Island

A Hurricane Watch is in effect for…* Andros Island

A Tropical Storm Warning is in effect for…* North of Deerfield Beach to Sebastian Inlet

A Tropical Storm Watch is in effect for…* North of Golden Beach to Deerfield Beach

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. Preparations to protect life and
property should be rushed to completion.

A Hurricane Watch means that hurricane conditions are possible within the watch area.

A Tropical Storm Warning means that tropical storm conditions re expected within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours.

Interests elsewhere in southern and central Florida should continue to monitor the progress of Dorian. Additional watches or warnings may be required for portions of the east coast of Florida today.

For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service.

Tropical storm conditions are expected within the tropical storm warning area on Monday.

Tropical storm conditions are possible within the tropical storm watch area by Monday night.

STORM SURGE: A life-threatening storm surge will raise water levels by as much as 15 to 20 feet above normal tide levels in areas of onshore winds on the Abaco Islands and Grand Bahama Island. Near the coast, the surge will be accompanied by large and destructive waves.

RAINFALL: Dorian is expected to produce the following rainfall totals through late this week:

Northwestern Bahamas…12 to 24 inches, isolated 30 inches.
Coastal Carolinas…5 to 10 inches, isolated 15 inches.
Central Bahamas and the Atlantic Coast from the Florida peninsula
through Georgia…2 to 4 inches, isolated 6 inches.

This rainfall may cause life-threatening flash floods.

SURF: Large swells will affect the east-facing shores of the Bahamas, the Florida east coast, and the southeastern United States coast during the next few days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office.”

For further information on the storm visit: https://www.nhc.noaa.gov

By Lynn Jenner
NASA Goddard Space Flight Center