Featured Images

Text Size

Hurricane Season 2010: Hurricane Tomas (Atlantic Ocean)
11.10.10
 
November 10, 2010

NASA's TRMM Satellite Sees Severe Flooding In Caribbean from Tomas

TRMM rainfall totals are shown here for the central and western Caribbean from Oct. 31 to Nov. 7, 2010. › View larger image
TRMM rainfall totals are shown here for the central and western Caribbean from Oct. 31 to Nov. 7, 2010, in association with the passage of Tomas. The solid white line shows Tomas' path with appropriate storms symbols marking the 00Z and 12Z (for 12 Zulu Time – which is 7 a.m. EST) positions and intensity. The heaviest rains fell off shore north of the Columbian and Venezuelan coasts in and around Aruba with amounts exceeding 350 mm (~14 inches, shown in purple). Tomas brought upwards of 250 mm of rain (~10 inches, shown in red) to far southwestern Haiti and generally between 100 and 200 mm (~4 to 6 inches, shown in green and yellow) to the rest of Hispaniola.
Credit: SSAI/NASA, Hal Pierce Haiti was spared a direct hit by Hurricane Tomas as the center passed through the Windward Passage between Haiti and eastern Cuba, but the storm did bring heavy rains and gusty winds to the west coast of Haiti west of the capital of Port-au-Prince. The TRMM satellite captured data during from Oct. 7 through Nov. 7 and revealed excessive amounts of rainfall in the central and western Caribbean.

Tomas, the 19th named storm of the 2010 Atlantic hurricane season, formed from an African easterly wave moving westward across the central Atlantic. Tomas was responsible for 14 fatalities as it passed through the Lesser Antilles as a Category 1 storm.

The storm briefly reached Category 2 intensity before encountering southwesterly wind shear as it was passing over the southern Caribbean, causing it to weaken to a tropical storm and then a depression. Tomas turned northward over the central Caribbean and began to regain some of its intensity as it headed north towards Haiti. Tomas again became a hurricane as it passed by Haiti and headed northeast through the Turks and Caicos Islands.

The Tropical Rainfall Measuring Mission (or TRMM) satellite was launched way back in November of 1997 with the primary mission of measuring rainfall from space using a combination of passive microwave and active radar sensors. The TRMM-based, near-real time Multi-satellite Precipitation Analysis (TMPA) at the NASA Goddard Space Flight Center uses TRMM data to calibrate other satellites to obtain estimates of rainfall over the global Tropics.

TMPA rainfall totals were compiled for the central and western Caribbean from October 31 to November 7, 2010, in association with the passage of Tomas. TRMM data revealed that the heaviest rains fell off shore north of the Columbian and Venezuelan coasts in and around Aruba with amounts exceeding 350 mm (~14 inches).

Tomas brought upwards of 250 mm of rain (~10 inches) to far southwestern Haiti and generally between 100 and 200 mm (~4 to 6 inches to the rest of Hispaniola. Haiti, which has long been vulnerable to tropical systems due to its topography and poor land conditions, reported 20 fatalities from the storm.

TRMM is a joint mission between NASA and the Japanese space agency JAXA.

Text Credit: Steve Lang
SSAI/NASA Goddard Space Flight Center


November 8, 2010

GOES-13 Satellite Sees Cold Front Stalking Remnant Low of Tomas

Tomas' remnants are the tight swirl of clouds at the bottom of that line of clouds (near Bermuda). › View larger image
The GOES-13 satellite captured an image of the cold front stalking Tomas' remnants in the Atlantic Ocean on Nov. 8 at 1345 UTC (8:45 a.m. EST). The cold front is the line of clouds east of the U.S. East coast that looks like a question mark. Tomas' remnants are the tight swirl of clouds at the bottom of that line of clouds (near Bermuda).
Credit: NOAA/NASA GOES Project The GOES-13 satellite is watching a flurry of activity in the Atlantic Ocean today as a cold front approaches the remnants of Hurricane Tomas and threatens to swallow it in the next couple of days.

Tomas is now a remnant low pressure area is located in the Atlantic near 26 North and 68 West hundreds of miles south-southwest of Bermuda and has a minimum central pressure of 994 millibars today, Nov. 8. A cold front off the U.S. East Coast however, is stalking Tomas' remnants and moving east threatening to swallow the former hurricane.

The Geostationary Operational Environmental Satellite known as GOES-13 captures visible images of the eastern half of the U.S. and Atlantic Ocean basin during daylight hours and infrared images during night-time hours. Two GOES satellites cover the U.S., one the western half of the country, and the other, GOES-13, the eastern half of the country. GOES satellites are operated by NOAA, and the NASA GOES Project at NASA's Goddard Space Flight Center in Greenbelt, Md. creates images and animations using the satellite data.

GOES-13 captured an image of the cold front stalking Tomas' remnants in the Atlantic Ocean on Nov. 8 at 1345 UTC (8:45 a.m. EST). The cold front appears on the satellite imagery as a line of clouds east of the U.S. East coast that looks like a question mark. Tomas' remnants appear as a tight swirl of clouds at the bottom of that line of clouds near Bermuda.

By 6 p.m. Eastern Standard Time on Nov. 7, Tomas had lost its tropical characteristics and its warm core. Tomas had more resembled a frontal system with cold air stratocumulus clouds wrapping into its center. At that time, Tomas was about 500 miles south-southwest of Bermuda near 26.1 North and 69.1 West. It still had maximum sustained winds of 60 mph, and more resembled a nor'easter meteorologically speaking. It was moving north-northeast near 3 mph and had a minimum central pressure of 997 millibars at that time. When Tomas was at that location, the National Hurricane Center issued their last advisory on the system.

Tomas' remnant low pressure area has become a "post-tropical cyclone" and is forecast to continue moving northeast and east-northeastward until it is absorbed by a frontal system.

That cold front is currently located to the west of Tomas near 32 degrees North latitude and 66 degrees West longitude. It is expected to continue moving east and absorb Tomas' remnants in the next day or two.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, MD


November 5, 2010

NASA's MODIS Sees Hurricane Tomas Moving Through Windward Passage

MODIS captured this visible image of Hurricane Tomas over Haiti, Cuba, Jamaica, and the Dominican Republic on Nov. 5. › View larger image
The MODIS instrument on NASA's Terra Satellite captured this visible image of Hurricane Tomas over Haiti, Cuba, Jamaica, and the Dominican Republic at 15:30 UTC (11:30 a.m. EDT) on Nov. 5.
Credit: NASA/MODIS Rapid Response Team The center of Hurricane Tomas was moving through the Windward Passage today, Nov. 5, at 2 p.m. EDT, and NASA's Terra satellite captured a visible image of the rainmaker.

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Terra satellite captured a visible image of Hurricane Tomas at 15:30 UTC (11:30 a.m. EDT), just before it started moving through the Windward Passage.

Located in the Caribbean Sea, the Windward Passage is a strait located between eastern Cuba and the northwest of Haiti.

In satellite imagery, Tomas' convection (rapidly rising air that forms the thunderstorms that power the tropical cyclone) was described by the National Hurricane Center as "looking a little ragged" hinting that they are weaker and possibly more disorganized, due to the interaction with the mountains of Hispaniola.

MODIS instruments fly aboard NASA's Terra and Aqua satellites, and the MODIS Rapid Response Team at NASA's Goddard Space Flight Center in Greenbelt, Md. creates images from their data.

At 2 p.m. EDT, Tomas's center was 75 miles southeast of Guantanamo, Cuba, and 140 miles northwest of Port Au Prince, Haiti near latitude 19.8 North and longitude 74.0 West. Tomas is moving toward the north-northeast near 12 mph. The National Hurricane Center notes that "On the forecast track the center of Tomas will pass between northwestern Haiti and extreme eastern Cuba during the next few hours and near or over the southeastern Bahamas and the Turks and Caicos islands tonight or early Saturday.

Tomas' maximum sustained winds were still near 85 mph, and some strengthening is still possible today, but wind shear is expected to weaken Tomas thereafter. Tropical storm force winds extend out 140 miles from the center of the storm, and the minimum central pressure is 987 millibars.

As seen in GOES-13 satellite imagery earlier today, Tomas is to the east of a deep layer trough (elongated area of low pressure) and associated cold front over the eastern U.S. and western Atlantic Ocean. That front will help steer Tomas in a general north-northeasterly direction over the next 36-48 hours.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, MD


GOES-13 Satellite Sees Hurricane Tomas Lashing Haiti and Eastern Cuba Today

GOES-13 captured a visible image of Hurricane Tomas (bottom) on Nov. 5 at 1331 UTC over the southwestern tip of Haiti. › View larger image
The GOES-13 satellite captured a visible image of Hurricane Tomas (bottom) on Nov. 5 at 1331 UTC (9:31 a.m. EDT) centered over the southwestern tip of Haiti. The clouds to the north of Tomas are associated with a cold front off the eastern U.S. coast.
Credit: NOAA/NASA GOES Project Tomas strengthened to hurricane status and is currently lashing Hispaniola and eastern Cuba today and the GOES-13 satellite provided a visible image of its extensive cloud cover.

The Geostationary Operational Environmental Satellite known as GOES-13 captured a visible image of Hurricane Tomas on Nov. 5 at 1331 UTC (9:31 a.m. EDT) centered over the southwestern tip of Haiti. In the image the clouds to the north of Tomas are associated with a cold front off the eastern U.S. coast. GOES satellites are operated by NOAA. The NASA GOES Project at NASA's Goddard Space Flight Center in Greenbelt, Md. created today's GOES-13 image, and other images and animations using GOES satellite data.

During the morning hours of Nov. 5, Tomas' maximum sustained winds were around 85 mph and is a category one hurricane on the Saffir-Simpson scale. The National Hurricane Center in Miami, Fla. noted that Tomas could strengthen further today, then begin to weaken on Saturday, Nov. 6.

Hurricane force winds extend outward up to 15 miles from the center, and tropical-storm-force winds extend outward up to 140 miles especially northeast through southeast of the center. That makes the storm about 280 miles stretching from northeast to southeast.

At 8 a.m. EDT on Nov. 5, Tomas' center was about 80 miles south-southeast of Guantanamo, Cuba and 160 miles west of Port Au Prince Haiti, near 18.8 North latitude and 74.7 West longitude. Minimum central pressure is near 987 millibars. Tomas is moving to the northeast near 10 mph, and is expected to speed up over the next couple of days.

At 9 a.m. EDT, the airport at Port Au Prince, Haiti was reporting rain with easterly winds near 14 mph, gusting to 25 mph. Satellite imagery at 9:47 a.m. EDT showed Tomas' cloud cover extended from the Dominican Republic in the east, westward to Santiago de Cuba and Guantanamo, Cuba. Turks and Caicos Islands were also under Tomas' cloud cover at that time.

Tomas' center was western Haiti this morning (Nov. 5), near extreme eastern Cuba today, and over the southeastern Bahamas and Turks and Caicos Islands later today and tonight.

Hurricane warnings are in effect for Haiti, the southeastern Bahamas and Turks & Caicos Islands, and the province of Guantanamo in Cuba. Tropical storm warnings are up for Jamaica and the provinces of Santiago de Cuba and Holguin in Cuba. A Tropical storm watch is in effect for the southern coast of the Dominican Republic from the Haiti border east to Barahona .

Rainfall is a serious threat from Tomas, particularly in the mountainous areas of Haiti and the Dominican Republic where hillsides have been denuded of forests. These rains could cause life-threatening flashfloods or mudslides. Haiti and the Dominican Republic can expect 5 to 10 inches of rain, locally up to 15 inches. Jamaica may get 1 to 3 inches of rain. The Turks and Caicos Islands and the Bahamas could see 3 to 6 inches.

The National Hurricane Center expects storm surge to be greatest in southeastern Cuba. Surge of 1 to 3 feet above normal tide levels can be expected along the coast of Haiti and 3 to 5 feet in southeastern Cuba, in areas of onshore winds. The surge will be accompanied by large and destructive waves. Forecast updates can be found at the National Hurricane Center's website: www.nhc.noaa.gov/.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, MD


November 4, 2010

NASA Satellite Data Confirms a Stronger Tropical Storm Tomas, Hurricane Warnings Up

AIRS showed Tomas's strong convective activity as indicated by high thunderstorms that were as cold as -63F. › View larger image
NASA's Aqua satellite AIRS instrument captured an infrared image of Tropical Storm Tomas' clouds (right) on Nov. 4 at 2:59 a.m. EDT. Tomas showed strong convective activity in his center as indicated by high thunderstorms (in purple) that were as cold as -63F. A second area of showers and thunderstorms located to the southwest of Tomas is associated with a trough of low pressure.
Credit: NASA/JPL, Ed Olsen
GOES-13 visible image of Tropical Storm Tomas on Nov. 4 at 1231 UTC on its way toward Haiti. › View larger image
The GOES-13 satellite captured a visible image of Tropical Storm Tomas on Nov. 4 at 1231 UTC (8:31 a.m. EDT) on its way toward Haiti. GOES-13 is operated by NOAA.
Credit: NOAA/NASA GOES Project NASA's infrared satellite imagery has confirmed that Tomas is intensifying as convection is strengthening and cloud tops within the system are getting colder.

Infrared imagery helps scientists detect cold top temperatures within a tropical cyclone, and Tomas' cloud tops have grown colder over the last 24 hours. Tomas showed strong convective activity in his center as indicated by high thunderstorms that were as cold as -63 degrees Fahrenheit. The colder the cloud tops, the higher and stronger the thunderstorms are that power the tropical cyclone. The infrared imagery was captured on Nov. 4 at 0659 UTC (2:59 a.m. EDT) by the Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA's Aqua satellite.

At 8 a.m. EDT on Nov. 4 Tomas had maximum sustained winds near 50 mph, and further strengthening is expected as wind shear remains light and sea surface temperatures remain warm. Tomas was located about 150 miles south-southeast of Kingston, Jamaica and 305 miles southwest of Port Au Prince, Haiti near 15.9 North and 76.0 West. It was moving north-northwest near 6 mph, and had a minimum central pressure of 998 millibars.

Another indication of strengthening is falling atmospheric pressure. When air pressure falls a tropical cyclone is intensifying, and hurricane hunter aircraft detected a drop in atmospheric pressure at 8:30 a.m. EDT this morning within Tomas to 997 millibars.

A tropical storm warning is in effect for Jamaica as Tomas nears. Tropical Storm conditions are expected within 24 to 36 hours of the warning area. The warning was posted at 8 a.m. EDT on Nov. 4. Tropical storm warnings are also in effect for the south coast of the Dominican Republic from the Haiti border east to Barahona, and in Cuba, for the provinces of Guantanamo, Santiago de Cuba and Holguin.

Hurricane warnings are now in effect for Haiti, southeastern Bahamas and the Turks and Caicos Islands.

The National Hurricane Center (NHC) in Miami, Fla. is expecting very heavy rainfall amounts with Tomas. NHC stated that "Haiti and the Dominican Republic can expect 5 to 10 inches of rain, locally up to 15 inches. Jamaica may get 1 to 3 inches of rain. These rains could cause life-threatening flashfloods or mudslides. The Turks and Caicos Islands and the Bahamas could see 3 to 6 inches."

In addition to the heavy rainfall, storm surges between 1 to 3 feet above normal tide levels can be expected in the warning area in areas of onshore flow.

Tropical Storm Tomas continues to track north-northwest toward the Windward Passage and eastern Hispaniola. Satellite imagery shows that scattered showers and thunderstorms that are associated with Tropical Storm Tomas are in the area between 15 and 19 degrees North and 67 to 79 West, covering a large area.

AIRS infrared satellite imagery showed a second area of showers and thunderstorms with strong convection, located to the southwest of Tomas. Computer models indicate that those showers are associated with a monsoon trough, or an elongated area of low pressure. That trough stretches a long distance from southwest of Tomas near 13 North and 78 West, west to Costa Rica and into the eastern Pacific Ocean.

A low- to mid-level ridge of high pressure (an elongated area of high pressure) is sitting over the western central Atlantic Ocean today is steering Tomas to the north-northwest and then north as it moves around the edge of the high. The high acts as a wall that Tomas can't break through, so it circles the high's perimeter.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, MD


November 3, 2010

NASA's TRMM Satellite Sees Tomas' Power Fluctuate

Tomas' center of circulation wasn't evident on Nov. 3 so a tropical storm symbol was overlaid to show its location. › View larger image
Tomas' center of circulation wasn't evident when TRMM passed over Tomas on Nov. 3 at 2005 UTC (4:05 p.m. EDT) so a tropical storm symbol was overlaid to show its location. The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches per hour.
Credit: NASA/SSAI, Hal Pierce The Tropical Rainfall Measuring Mission (TRMM) satellite traveled over Tomas twice on Tuesday, Nov. 2. The second time was at 2005 UTC (4:05 p.m. EDT) when it was still classified as a tropical storm. During TRMM's second overpass, Tomas' center of circulation wasn't evident. Today, Nov. 3 that center is reforming.

During the morning hours on Nov. 3, an Air Force hurricane hunter aircraft found no tropical storm force winds so Tomas was downgraded by the National Hurricane Center to a tropical depression.

At 2 p.m. EDT on Nov. 3, Tomas was undergoing some changes, and its center was re-forming farther to the northeast from where it was before. The center is now located near 14.8 North and 75.0 West, about 245 miles south-southeast of Kingston, Jamaica and 315 miles southwest of Port Au Prince, Haiti. Maximum sustained winds were still at 35 mph, making Tomas still a depression. It was moving to the north-northwest near 7 mph and had a minimum central pressure of 1006 millibars. A turn toward the north and north-northeast is expected over the next 48 hours.

A Tropical Storm Watch has now been posted for Jamaica, and Haiti, the Dominican Republic, southeastern Cuba, the southeastern Bahamas and Turks and Caicos Islands should watch Tomas' track.

Tomas is expected to produce total rain accumulations of 5 to 10 inches over much of Haiti with possible isolated maximum amounts of 15 inches.

Tomas is now predicted to strengthen into a tropical storm and not reach hurricane strength. An upper level trough is predicted to steer a stronger Tomas through the Windward Passage between Cuba and Haiti by Friday.

Text Credit: Hal Pierce/Rob Gutro
SSAI/NASA Goddard Space Flight Center, Greenbelt, MD


NASA Satellite Sees Tomas Weaken to a Tropical Depression… For Now

Remaining strong, high thunderstorm cloud tops (purple) appear scattered around the depression's center of circulation. › View larger image
This infrared image of Tropical Depression Tomas was captured by the Atmospheric Infrared Sounder (AIRS) instrument aboard NASA's Aqua satellite on Nov. 3 at 06:17 UTC (2:17 a.m. EDT). Remaining strong, high thunderstorm cloud tops (purple) appear scattered around the depression's center of circulation.
Credit: NASA/JPL, Ed Olsen
Tomas was producing many strong thunderstorms with heavy rainfall (red) of over 2 inches per hour › View larger image
The TRMM satellite passed over Tomas at 0515 UTC (1:15 a.m. EDT and revealed that Tomas was producing many strong thunderstorms with heavy rainfall (red) of over 2 inches per hour over a large area of the Caribbean Sea.
Credit: NASA/SSAI, Hal Pierce NASA infrared satellite data from this morning revealed that Tropical Storm Tomas has weakened into a tropical depression.

Tomas is in the central Caribbean Sea headed for Haiti this weekend, and forecasters are calling for a re-intensification before it makes landfall.

The National Hurricane Center (NHC) in Miami, Fla. reported at 5 a.m. EDT on Nov. 3 that hurricane hunter aircraft found an "ill-defined and elongated circulation with no tropical storm-force winds at the flight level or the surface." Thus, the status of Tomas was changed from a tropical storm to a tropical depression.

When NASA's Aqua satellite passed over Tomas on Nov. 3 at 06:17 UTC (2:17 a.m. EDT), the Atmospheric Infrared Sounder (AIRS) instrument onboard captured an infrared image of the cold thunderstorms within the system. The image showed that strong, high thunderstorm cloud tops appeared disorganized and scattered around the depression's center of circulation. The cloud tops have also warmed, indicating that the convection is not as strong as it was the day before.

What a difference 24 hours can make with a tropical cyclone. On the previous day, the Tropical Rainfall Measuring Mission (TRMM) satellite passed over Tomas at 0515 UTC (1:15 a.m. EDT). At that time, TRMM noticed that vertical wind shear (winds that can weaken a tropical cyclone) relaxed allowing Tomas to temporarily re-strengthen a little. At that time, data from TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) revealed that Tomas was producing many strong thunderstorms over a large area of the Caribbean Sea. Since that time, the strength of Tomas' thunderstorms has waned.

Tomas is now a disorganized depression, and is moving at 5 mph toward the west-northwest. Tomas' maximum sustained winds were down to 35 mph. It was centered about 305 miles south-southeast of Kingston, Jamaica and 410 miles southwest of Port Au Prince, Haiti. The NHC estimates that Tomas' center is near 13.7 North and 75.8 West.

The National Hurricane Center's forecast still calls for Tomas to re-intensify into a hurricane before reaching Haiti late Friday, so residents should prepare for its arrival.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, MD


November 2, 2010

GOES-13 Catches Tropical Storm Tomas' Early Morning Strengthening

GOES-13 captured a strengthening Tropical Storm Tomas this morning, Nov. 2 at 0845 UTC in infrared imagery. › View larger
The GOES-13 satellite captured a strengthening Tropical Storm Tomas this morning, Nov. 2 at 0845 UTC (4:45 a.m. EDT) in infrared imagery. Tomas appears as the rounded area of clouds (bottom right) about 310 miles due south of Port Au Prince, Haiti. In the larger image, the clouds over northwestern Louisiana (top left) are from a low and associated cold front stretching southwest to north-central Mexico.
Credit: NOAA/NASA GOES Project The GOES-13 satellite keeps a continuous eye on the eastern half of the U.S. and Atlantic Ocean basin, and has provided meteorologists with an infrared look at a strengthening Tropical Storm Tomas this morning.

The Geostationary Operational Environmental Satellites like GOES-13 are managed by NOAA. The NASA GOES Project at NASA's Goddard Space Flight Center in Greenbelt, Md. creates images and animations from the GOES satellite data. When GOES-13 provided an infrared image (because it was taken at night) today, Nov. 2 at 0845 UTC (4:45 a.m. EDT), Tropical Storm Tomas showed a little more organization in its clouds after battling wind shear yesterday.

Infrared satellite data also showed that convection (rapidly rising air that form the thunderstorms that make up a tropical cyclone) has increased or deepened in Tomas. This morning most of that convection and thunderstorm activity is occurring over the eastern and northeastern areas around the center of circulation.

The wind shear over the south-central Caribbean Sea has weakened which has allowed Tomas to gradually re-strengthen. The waters are also much warmer than the 80 degree threshold needed to maintain or strengthen a tropical cyclone. Because of these improving conditions, the National Hurricane Center forecasts that Tomas will continue strengthening until Friday when an upper-level trough (elongated area of low pressure) will push Tomas north-northeastward toward the Windward Passage and parts of Hispaniola.

At 5 a.m. EDT, Tropical Storm Tomas had maximum sustained winds near 50 mph (up from 45 mph on Nov. 1). Tomas is moving west near 12 mph and has a minimum central pressure of 1003 millibars. The center of Tomas is located about 355 miles south of Port-au-Prince, Haiti near 13.5 North and 72.0 West. Tomas is being steered along the southern and southwestern edge of ridge (an elongated area) of high pressure which is moving Tomas west.

To visualize Tomas' movement, picture a penny on a table and move your finger from the bottom of the penny to the left. The penny is the area of high pressure, and your finger would be Tomas. High pressure areas act as a wall that tropical cyclones can't penetrate, so they move around the edges.

Tomas is forecast to become a hurricane on Thursday, Nov. 4 and turn to the northeast, threatening Haiti. Currently there are no watches and warnings in effect, but that's likely to change later this week.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, MD


November 1, 2010

TRMM Satellite Sees a Weaker Tropical Storm Tomas

The TRMM satellite passed over Tomas on Sunday, Oct. 31 measuring intense rainfall, falling at about 2 inches per hour. › View larger image
The TRMM satellite passed over Tomas on Sunday, Oct. 31 at 2021 UTC (4:21 p.m. EDT). The red areas represent intense rainfall, falling at about 2 inches per hour. The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches per hour. Red areas are heavy rainfall at almost 2 inches per hour.
Credit: NASA/SSAI, Hal Pierce Tomas reached hurricane strength over the weekend, and has been weakening since and is currently a tropical storm. The Tropical Rainfall Measuring Mission (TRMM) satellite passed over Tomas on Oct. 31 and captured its rainfall rates.

On Nov. 1 at 1500 UTC (11 a.m. EDT) Tomas was located over the south-central Caribbean Sea and its maximum sustained winds were down to 45 mph. It was located about 90 miles north-northeast of Curacao and 420 miles southeast of Port Au Prince, Haiti near 13.6 North and 68.7 West. It was moving west-southwest near 14 mph and had a minimum central pressure of 1005 millibars.

When the TRMM satellite passed over Tomas on Sunday, Oct. 31 at 2021 UTC (4:21 p.m. EDT), it was still a minimal hurricane with maximum sustained winds near 75 mph.

During its short time as a hurricane Tomas caused widespread destruction, injuries and possibly deaths in Barbados, St. Vincent and St. Lucia. TRMM's rainfall analysis was created from TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) instruments. The analysis showed that Tomas was causing a large area of moderate to heavy rainfall, with some areas receiving as much as 2 inches per hour.

By 0300 UTC (11 p.m. EDT) on Sunday, Oct. 31 Tomas had weakened and was downgraded to a tropical storm. Westerly vertical wind shear has been predicted to further weaken Tomas in the next 24 hours.

The National Hurricane Center forecasts Tomas to strengthen again within two days and threaten the nation of Haiti.

Text Credit: Rob Gutro and Hal Pierce
NASA TRMM Team NASA Goddard Space Flight Center, Greenbelt, MD


NASA's CloudSat satellite Views Hurricane Tomas' Powerful Thunderstorms

NASA's CloudSat satellite's Cloud Profiling Radar captured a look across Tomas on Oct. 31 › View larger image
NASA's CloudSat satellite's Cloud Profiling Radar captured a look across Tomas on Oct. 31 at 0549 UTC (1:49 a.m. EDT). The blue areas along the top of the clouds indicate cloud ice. The wavy blue lines on the bottom center indicate intense rainfall. Where the solid line along the bottom disappears there is intense rainfall exceeding 30mm/hr (1.18 inches/hour). Tomas' highest clouds were over 9 miles high.
Credit: NASA/JPL/Colorado State Univ./NRL-Monterey Tomas formed quickly this past weekend in the eastern Caribbean Sea, grew into a hurricane and lashed Hispaniola before weakening. NASA's CloudSat satellite captured a look at Tomas' cloud heights and heavy rainfall when it was a hurricane.

NASA's CloudSat satellite's Cloud Profiling Radar captured a look across Tomas on Oct. 31 at 0549 UTC (1:49 a.m. EDT). At that time, Tomas' maximum sustained winds were near 85 knots (97 mph) and it had a minimum central pressure of 982 millibars. CloudSat revealed that the top of Tomas' clouds reached up to 15 kilometers (over 9 miles) high. CloudSat also measured the cloud top temperatures are as cold as or colder than minus 60 degrees Celsius (minus 76 degrees Fahrenheit)!

At 5 p.m. EDT on Friday, Oct. 29 the nineteenth named storm formed southeast of the Windward Islands about 200 miles southeast of Barbados. On Saturday, Oct. 30 Tomas dropped heavy rainfall on Barbados and caused damages as it neared hurricane strength. By 11 a.m. EDT Oct. 30, Tomas had grown into the twelfth hurricane of the Atlantic Ocean season and was bearing down on St. Lucia and St. Vincent with maximum sustained winds of 75 mph. By 11 p.m. that day, Tomas' maximum sustained winds had reached 90 mph.

On Sunday, Oct. 31, Tomas' winds had strengthened to 100 mph, and it continued to lash the Windward Islands and much of the Lesser Antilles with heavy rainfall. By 5p.m. Tomas had weakened because of westerly wind shear and the maximum sustained winds were down to 75 mph.

At 5 a.m. EDT today, Nov. 1, Tomas' maximum sustained winds were down to 50 mph, and it was moving west near 14 mph. Tomas is expected to continue moving west until Wednesday, Nov. 3 when it is forecast to turn to the north-northwest.

Westerly wind shear has increased today, and has pushed the deepest convection away from the center by 100 miles. Additional weakening is likely, according to the National Hurricane Center, as winds shear of 20 to 25 knots (23-29 mph) will continue battering Tomas for another day. Tomas is currently centered about 135 miles northeast of Curacao near 13.8 North and 67.7 West and will continue raining on the Windwards and Lesser Antilles today.

Text Credit: Rob Gutro and Hal Pierce
NASA Goddard Space Flight Center, Greenbelt, MD
 
› Back To Top