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Hurricane Season 2009: Hurricane Bill (Atlantic)
08.25.09
 
 
August 25, 2009

Hurricane Bill when he was over Nova Scotia, Canada on August 23 at 11:20 a.m. EDT. > View larger image
NASA's MODIS instrument that flies on the Terra satellite captured this cool image of Hurricane Bill when he was over Nova Scotia, Canada on August 23 at 11:20 a.m. EDT, as a Category One hurricane.
Credit: MODIS Rapid Response Team
Hurricane Bill's winds using microwaves to see through his clouds, on August 6:26 p.m. EDT. > View larger image
NASA's QuikScat captured an image of Hurricane Bill's winds using microwaves to see through his clouds, on August 6:26 p.m. EDT. The white area in Bill's center indicates winds over 63 mph. Wind direction is indicated by small barbs. White barbs point to areas of heavy rain.
Credit: NASA/JPL, Peter Falcon
Bill on the edge of its easternmost view on August 25 at 1145 UTC (7:45 a.m. EDT). > View larger image
The GOES-12 satellite captured Bill on the edge of its easternmost view on August 25 at 1145 UTC (7:45 a.m. EDT).
Credit: NASA/GOES Project
Bill Rained on Canada, Aiming for Great Britain on Wednesday

Hurricane Bill drenched eastern Canada on his sweep by yesterday, August 24, bringing heavy rains to Nova Scotia, Prince Edward Island and Newfoundland. Tomorrow, he'll bring his remnants will rain on Great Britain and they'll hang around for two days.

On Monday, August 24 Hurricane Bill skirted eastern Canada on its way out into the North Atlantic Ocean. Bill brought gusty winds, heavy surf and heavy rains to the region. Bill downed trees and power lines, and putting 40,000 people in the dark in Halifax, Nova Scotia. Environment Canada, the meteorological organization for Canada, reported that up to 0.8 inches of rain fell in an hour at the Halifax airport. Bill forced the cancellation of flights Sunday afternoon at Halifax Stanfield International Airport and disrupted ferry service between Nova Scotia and Newfoundland.

At the beaches, five-to-seven meter waves swept over the sands and into nearby roadways, causing flooding. Highways to Peggy's Cove and Lawrencetown Beach in Halifax were closed.

Bill was a huge storm, spanning 460 miles in diameter. NASA satellites were able to capture Bill's size in a number of ways. From Bill's cloud cover to the extent of his winds. The Moderate Imaging Spectroradiometer or MODIS instrument on NASA's Terra satellite provided clear images of Bill's cloud cover, showing the large area that Bill covered. NASA's QuikScat satellite was able to peer through those clouds using microwave technology and actually measure the winds on the surface of the ocean beneath Hurricane Bill, confirming his category one hurricane strength as he passed Nova Scotia.

Fortunately, the northeast quadrant of the storm remained at sea, as that's where the strongest winds are located in a hurricane. Oil and gas platforms and ships at sea dealt with those winds. The storm came as close as 46 miles fromHalifax, Nova Scotia, which was within the area of hurricane-force winds. Marine buoys off the southern coast of the city reported gusts to 80 miles per hour.

Remnants of Bill will be moving into Great Britain Wednesday, bringing heavy rain and gusty winds. Southwest Scotland and west Great Britain will see Bill's remnants exit and move east on Thursday, local time.

To download the GOES Hurricane movie from the GOES master scrapbook, visit: http://goes.gsfc.nasa.gov/text/hotstuff.html.

Text credit: Rob Gutro/NASA's Goddard Space Flight Center











August 24, 2009

Movie still showing the progression of Hurricane Bill from Bermuda to the Canadian Maritimes. > View video
NASA's GOES Project created a movie of satellite data from August 21-23 showing the progression of Hurricane Bill from Bermuda to the Canadian Maritimes.
Credit: NASA/GOES Project, Dennis Chesters
The large extent of Bill's clouds over Nova Scotia and Newfoundland, Canada. > View larger image
NASA's AIRS instrument captured the large extent of Bill's clouds on Sunday, August 23 at 12:59 p.m. EDT as he was raining and gusting over Nova Scotia and Newfoundland, Canada.
Credit: NASA JPL, Ed Olsen
NASA GOES Project Satellite Movie: Bill Heads North to Canada

Bill lost his tropical characteristics today, August 24, as he's moved past Newfoundland and is tracking east in the North Atlantic Ocean. NASA's GOES Project at the NASA Goddard Space Flight Center created a satellite movie of Bill's track up the east coast and into the Canadian Maritimes from August 21 through August 23.

The Geostationary Operational Environmental Satellite, GOES-12, operated by the National Oceanic and Atmospheric Administration captures images of U.S. East Coast weather continuously. Those images were compiled into a movie from the NASA GOES Project and showed Bill's track from just west of Bermuda northward into the Canadian Maritimes from August 21-23.

On August 24, by 5 a.m. EDT today, Extra-tropical Storm Bill was still packing sustained winds near 70 mph, just under hurricane status. He was located 190 miles northeast of Cape Race, Newfoundland, Canada, near 48.6 north and 50.2 west. All watches and warnings for Newfoundland have been discontinued. Bill is now speeding along at 43 mph toward the east-northeast. Estimated minimum central pressure is 980 millibars.

As is typical when storms become extra-tropical, they expand. That's what Bill has done. Bill's tropical storm force winds now extend to 315 miles from the center making him a huge storm. Traffic in the north Atlantic shipping lanes should be aware that Bill is producing a huge area of storm and gale-force winds today and the next two days.

NASA's Aqua Satellite also got a stunning look at Hurricane Bill using infrared imagery. The Infrared imagery acts like a thermometer with tropical cyclones and can measure their cloud top temperatures. The colder the clouds, the higher and more powerful the thunderstorms. AIRS instrument captured the large extent of Bill's clouds on Sunday, August 23 at 12:59 p.m. EDT as he was raining and gusting over Nova Scotia and Newfoundland, Canada.

Two deaths in the U.S. were attributed to Bill, and both to the rough surf the storm generated. In Volusia County, Florida at New Smyrna Beach a 54-year-old man died trying to body surf in Bill's dangerous waves. At Acadia National Park, Maine, a 7 year old girl was swept out to sea with a dozen others when tremendous waves battered the coast. Maine Public Safety Department confirmed that the girl was the only one of the twelve that did not survive.

Bill will continue to create dangerous conditions in the North Atlantic for the next couple of days as he heads toward Great Britain.

To download the GOES Hurricane movie from the GOES master scrapbook, visit: http://goes.gsfc.nasa.gov/text/hotstuff.html.

Text credit: Rob Gutro/NASA's Goddard Space Flight Center



August 22, 2009

AIRS image of Bill > View larger image
This infrared satellite image shows Bill's clouds (depicted in purple and blue) on August 23 at 1:53 a.m. EDT indicating high, cold powerful thunderstorms still around the eye. Bill was a Category One Hurricane with sustained winds near 85 mph at this time.
Credit: NASA JPL, Ed Olsen
NASA Sees Some Strong Thunderstorms in Bill's Center As he Drenches Eastern Canada

Bill is still holding onto hurricane status near Nova Scotia, and will be bringing a lot of rain and heavy surf to Nova Scotia, Prince Edward Island and Newfoundland. Today, Sunday, August 23, NASA infrared satellite imagery revealed cold high thunderstorm clouds around Bill's eye, indicating there is still some powerful convection and strong thunderstorms happening in the storm.

At 800 a.m. EDT, on August 23, Bill still had maximum sustained winds near 85 mph, making him a Category One hurricane on the Saffir-Simpson scale. Minimum central pressure was 965 millibars. He was located 175 miles south-southwest of Halifax, Nova Scotia, Canada, near 42.4 north and 65.4 west, and was racing to the northeast near 31 mph, bringing the center of Bill near or over southeastern Newfoundland tonight or early Monday.

NASA's Aqua satellite flew over Hurricane Bill and the Atmospheric Infrared Sounder (AIRS) instrument onboard captured this infrared image from this morning at 1:53 a.m. EDT (05:53 UTC). The National Hurricane Center noted in their discussion, "Infrared satellite imagery shows cold convective cloud tops continue to surround the cloud-filled eye of Bill." The AIRS image from early this morning did show a very small eye in Bill, despite being filled with clouds. The National Hurricane Center noted that "Recent aircraft fixes have been to the west and southwest of the eye-feature seen in satellite imagery suggesting some vertical tilt to the hurricane."

In the AIRS image from this morning Bill is seen almost parallel to the Massachusetts coast, out at sea. He continues to move northeast and will be moving across the "northern wall" of the Gulf Stream later today, and into cooler waters which will sap his strength more. He is expected to continue weakening over the next day and a half as he races across the North Atlantic Ocean toward Great Britain. During that time, Bill is also expected to become extratropical, losing the warm core characteristics and taking on a cold core center, much like a typical low pressure system in the northern hemisphere.

Nova Scotia, Prince Edward Island and Newfoundland can expect lot of rain from Bill as he races past. Total rainfall expected is 3-5 inches with isolated maximum amounts up to 7 inches. For live Nova Scotia radar from Environment Canada, go to: > Canadian weather office web site

Ocean swells are also a danger, just as they continue to be along the Mid-Atlantic and northeast U.S. today and tomorrow.

Text credit: Rob Gutro/NASA's Goddard Space Flight Center



August 22, 2009

AIRS image of Hurricane Bill > View larger image
This infrared satellite image shows Bill's clouds (depicted in purple and blue) on August 22 at 2:47 a.m. EDT indicating high, cold powerful thunderstorms. The image doesn't clearly show an eye in the storm, but Bill is still strong Category Two Hurricane with sustained winds near 105 mph.
Credit: NASA JPL, Ed Olsen
Cape Cod, Massachusetts Readies for Hurricane Bill Late Today

Residents of Cape Cod, Massachusetts should be making last minute preparations for Hurricane Bill, especially if they live along the beaches, because the hazardous surf will be their biggest concern. Local National Weather Service forecasters are also expecting maximum sustained winds gusting between 30 and 40 knots with higher gusts. Bill will be closest to Cape Cod late tonight (Saturday, August 22) through early tomorrow morning.

A Tropical Storm Warning continues for Woods Hole to Sagamore Beach, Massachusetts, including Cape Cod Bay, Nantucket and Vineyard Sounds, Buzzards Bay as well as the coastal waters east of Cape Cod and south of Nantucket and Martha's Vineyard. Some strengthening is possible today, followed by weakening tonight and Sunday as the center of bill moves north of the Gulf Stream. Sustained tropical storm-force winds will affect the outer Cape and Nantucket.

NASA's Aqua and CALIPSO satellites were providing forecasters at the National Hurricane Center with valuable cloud and temperature information on Hurricane Bill, to assist with their forecasts.

NASA's Atmospheric Infrared Sounder (AIRS) instrument that flies on the Aqua satellite captured Bill's very cold clouds as he was parallel to North Carolina this morning, August 22 at 2:47 a.m. EDT. The image doesn't clearly show an eye in the storm, but Bill is still strong Category Two Hurricane with sustained winds near 105 mph.

In infrared imagery, NASA's false-colored purple clouds are as cold as or colder than 220 Kelvin or minus 63 degrees Fahrenheit (F). The blue colored clouds are about 240 Kelvin, or minus 27F. The colder the clouds are, the higher they are, and the more powerful the thunderstorms are that make up the cyclone. Today's image of Bill showed high thunderstorms, as cold as -63F!

Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the ocean waters, revealing warmer temperatures in orange and red. In today's satellite image from AIRS, the surrounding ocean waters were a deep orange, indicating sea surface temperatures of 80F or higher, which is necessary to help a hurricane maintain strength.

Another image on Aqua also captured Bill. The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Aqua satellite captured the breadth of Bill's clouds. Bill's tropical storm force winds extended more than 230 miles from his center today, and his cloud cover was even further.

CALIPSO image of Hurricane Bill> View larger image
Two perspectives on Hurricane Bill: A vertical profile from CALIPSO is overlaid on an image from MODIS as Bill moved northward on Aug. 19 at about 1:15 p.m. EST. MODIS captures the breadth of Bill and CALIPSO detected the upper portion of the hurricane’s clouds structure. The eye of the storm can be seen as the break in the clouds just south of 19.70 N, about parallel with the southern coast of Cuba. Credit: NASA LARC, Patrick Lynch
In addition to the Aqua satellite, NASA's Cloud-Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO) captured a vertical profile of the upper portion of the hurricane’s clouds structure. In an image taken on August 19, the eye of the storm was evident in the image taken by CALIPSO as it appeared as a break in the clouds just south of 19.70 N, about parallel with the southern coast of Cuba.

At 8 a.m. EDT, Bill's center was about 510 miles south of Nantucket, Massachusetts. Relative to the Mid-Atlantic and Bermuda, Bill was almost parallel to Cape Hatteras, North Carolina at 410 miles the Hatteras' east. Bill had already passed Bermuda, too. Bill was 235 miles west-northwest of Bermuda. He was near 34.0 North and 68.4 west, moving north at 22 mph. Bill's maximum sustained winds were near 105 mph and pressure was 960 millibars.

High and dangerous ocean swells and rip currents from Bermuda up the U.S. East coast are forecast today, Saturday, August 22, and tomorrow, Sunday, August 23. The Bermuda Weather Service said storm tide will raise water levels by as much as 3 feet above ground level along the coast along with large and dangerous battering waves.

Meanwhile, the southeast coast of the U.S. is already experiencing large swells, high waves, and rip currents. These conditions will continue to spread north along the U.S. coast and into the Canadian Maritimes today and tomorrow as Bill continues his northward track. These are extremely dangerous surf conditions and rip currents. Beachgoers and boaters are urged to not venture out to beaches or the eastern Atlantic this weekend.

Watches and warnings will likely be posted later for Nova Scotia, Canada and Newfoundland.

> NASA's CloudSat also captured an image of Hurricane Bill as a Category 4 Hurricane

Text credit: Rob Gutro/NASA's Goddard Space Flight Center



August 21, 2009

GOES-12 satellite image of Hurricane Bill on August 21 at 2:25 p.m. EDT > View video
NASA and NOAA's newest weather satellite, GOES-14, has captured some fascinating views of Hurricane Bill. This is a collection of a few quick movies put together by the GOES-14 team.
Credit: NASAOES Project
NASA Releases GOES-14 Satellite Video of Hurricane Bill

NASA has released a video of Hurricane Bill today from the GOES-14 satellite. The video was put together from a series of still frames taken by the satellite using both infrared and visible imagery and provides different views of Hurricane Bill on August 20.

Earlier this summer, NASA launched the latest Geostationary Operational Environmental Satellite, GOES-O. Recently operations have been turned over to the National Oceanic and Atmospheric Administration (NOAA) and the satellite was renamed GOES-14. The satellite is still being tested in orbit, and it captured video of Hurricane Bill on August 20, while it was on its way to Bermuda.

The spectacular video is a collection of a few quick movies put together by the GOES-14 team from the NASA GOES Project at NASA's Goddard Space Flight Center in Greenbelt, Md.

The video includes an impressive zoom-out, showing how big the hurricane is, relative to the hemisphere. Bill is a large hurricane, more than 1,200 kilometers (746 miles) across, and the storm’s partially cloud-filled eye is nearly 50 kilometers (31 miles) wide.

On August 20, the date of the movie, Hurricane Bill had sustained winds of 135 mph, making it a powerful Category 4 storm. At that time hurricane-force winds extended outward up to 80 miles from the center. On August 21, Bill's sustained winds were near 110 mph and hurricane force winds extended up to 115 miles.

For daily updates and new NASA satellite images on Hurricane Bill, visit NASA's Hurricane Web Page at http://www.nasa.gov/hurricane. For forecasts and advisories on Hurricane Bill, visit NOAA's National Hurricane Center page: http://www.nhc.noaa.gov/.

To download the GOES Hurricane movie from the GOES master scrapbook, visit: http://goes.gsfc.nasa.gov/text/hotstuff.html.

Text credit: Rob Gutro/NASA's Goddard Space Flight Center



Yellow, green and red areas indicate rainfall between .78 to 1.57 inches per hour and red and purple areas are considered moderate to heavy rainfall. > View larger image
TRMM captured Hurricane Bill's heavy rainfall on August 21 at 5:22 a.m. EDT. The yellow, green and red areas indicate rainfall between .78 to 1.57 inches per hour. The red and purple areas around Bill's eye are considered moderate to heavy rainfall.
Credit: NASA/SSAI, Hal Pierce
Bill's clouds indicating high, cold powerful thunderstorms. > View larger image
This infrared satellite image from the AIRS instrument on NASA's Aqua Satellite shows Bill's clouds (depicted in purple and blue) on August 21 at 2:11 a.m. EDT indicating high, cold powerful thunderstorms.
Credit: NASA JPL, Ed Olsen
NASA Watches as Hurricane Bill Sweeps Over Bermuda

Hurricane Bill is raining on Bermuda today, Friday, August 21, and NASA satellites are providing forecasters with information about Bill's rainfall, clouds and winds.

NASA and the Japanese Space Agency's Tropical Rainfall Measuring Mission (TRMM) satellite flew over the center of Hurricane Bill this morning capturing rainfall data.

TRMM rainfall images are false-colored with yellow, green and red areas, which indicate rainfall between 20 and 40 millimeters (.78 to 1.57 inches) per hour. TRMM captured Hurricane Bill's heavy rainfall on August 21 at 5:22 a.m. EDT. The yellow, green and red areas indicate rainfall between .78 to 1.57 inches per hour. The red and purple areas around Bill's eye are considered moderate to heavy rainfall.

According to the National Hurricane Center, Bill is expected to produce total rain accumulations of 1 to 3 Inches over Bermuda, with maximum amounts of 5 inches. Both a hurricane and tropical storm watch are in effect for Bermuda as the rain continues.

For live radar of Bermuda, from the Bermuda Weather Service, visit: http://www.weather.bm/radarLarge.asp.

The Aqua satellite also flew over Hurricane Bill early today, Friday, August 21, and provided valuable data on his cloud top temperatures. They're important because they tell forecasters how high thunderstorms are, and the higher the thunderstorm, the more powerful it is, and Bill is pretty powerful as a Category Three Hurricane on the Saffir-Simpson Scale.

In infrared imagery, NASA's false-colored purple clouds are as cold as or colder than 220 Kelvin or minus 63 degrees Fahrenheit (F). The blue colored clouds are about 240 Kelvin, or minus 27F. The colder the clouds are, the higher they are, and the more powerful the thunderstorms are that make up the cyclone.

Although Bill has weakened slightly over the last 24 hours, forecasters say it could regain a little strength before winds and cooler waters start battering it and weakening it. Bill is forecast to parallel the eastern U.S. coast and affect Nova Scotia, Canada, on its curved track into the North Atlantic Ocean this weekend. As Bill approaches the Canadian Maritimes it will undergo a transition into an extratropical storm.

At 11 a.m. EDT, Hurricane Bill had maximum sustained winds near 115 mph. He was moving northwest near 18 mph and is expected to turn to the north-northwest later today. His center is currently near latitude 27.6 north and longitude 66.3 west or about 335 miles south-southwest of Bermuda and about 755 miles southeast of Cape Hatteras, North Carolina. Minimum central pressure is 958 millibars.

Meanwhile a warning is in effect now about large, and dangerous ocean swells for a huge area in the eastern Atlantic. Large swells associated with Bill will be impacting the coasts of Puerto Rico; Hispaniola; the Bahamas; Bermuda the entire eastern United States; and the Canadian Maritimes. The National Hurricane Center warns "These swells will likely cause extremely dangerous surf and life-threatening rip currents. Please consult output from your local weather office for details."

Text credit: Rob Gutro/NASA's Goddard Space Flight Center



August 20, 2009

QuikScat used microwaves to peer through Bill's clouds and measure his winds on August 18 > View larger image
QuikScat used microwaves to peer through Bill's clouds and measure his winds on August 18 at 5:23 p.m. EDT when Bill was a powerful Category 4 hurricane.
Credit: NASA JPL, Peter Falcon
NASA's MODIS instrument on the Terra satellite captured Hurricane Bill > View larger image
NASA's MODIS instrument on the Terra satellite captured Hurricane Bill, located off the Lesser Antilles in the Atlantic Ocean on August 19 at 12:15 p.m. EDT.
Credit: NASA, MODIS Rapid Response
NASA's AIRS instrument on the Aqua satellite caught Bill's icy cold clouds on August 20 > View larger image

NASA's AIRS instrument on the Aqua satellite caught Bill's icy cold clouds on August 20 at 1:29 a.m. EDT as it was moving toward the Leeward Islands (left of the storm). Notice Bill's 30 mile wide eye is well-defined in the center of the storm. In this false-colored image, purple indicates Bill's high thunderstorm cloud temperatures are colder than minus 63F and blue is minus 27F or colder.
Credit: NASA JPL, Ed Olsen
NASA's QuikScat Sees Cat 3 Hurricane Bill's Winds Go a Long Distance

NASA satellites continue to capture important wind speed and cloud data that forecasters at the National Hurricane Center are using to help their forecasts. QuikScat has been particularly helpful in determining the extent of hurricane and tropical storm-force winds, and they go a great distance.

NASA's QuikScat satellite uses microwave technology to peer through the clouds and measure the surface winds of a tropical cyclone. On Thursday, August 19, QuikScat data found that Bill's hurricane force winds have dropped down to a Category 3 hurricane at 125 mph. However, forecasters note that Bill is moving into an area that could help him strengthen back to Category 4 hurricane on Friday or Saturday.

Bill's hurricane-force winds extend up to 85 miles from his center, about the distance from Staten Island, N.Y. to Philadelphia, Penn. Bill's Tropical storm force winds extend to as far as 230 miles from the center, and that's about the distance from New York City, N.Y. to Washington, D.C.!

At 5 a.m. EDT on August 19, Bill's maximum sustained winds had decreased to 125 mph, and he was moving northwest near 18 mph. That motion is expected to continue for a day until he turns to the north-northwest late Friday. Minimum central pressure was 949 millibars. Bill was located about 790 miles south-southeast of Bermuda and only 325 miles north-northeast of the Leeward Islands.

NASA's Terra satellite also flew over Bill, and using the Moderate Imaging Spectroradiometer (MODIS) instrument captured an image of the storm when it was located off the Lesser Antilles in the Atlantic Ocean on August 19 at 12:15 p.m. EDT. MODIS showed a strong hurricane with a well-defined eye.

NASA's Aqua satellite joined QuikScat and Terra to capture Hurricane Bill. Aqua's Atmospheric Infrared Sounder (AIRS) instrument captured Bill's frigid cloud temperatures on August 20 at 1:29 a.m. EDT. The imagery clearly showed Bill's 30- mile wide eye in the center of the storm, and indicated Bill's high thunderstorm cloud temperatures were colder than minus 63 Fahrenheit.

Hurricane Bill is hundreds of miles away from the U.S. coast today, but forecasters are cautioning about large swells the storm is creating already.

The National Hurricane Center noted that "Large swells associated with bill will be impacting the islands of the northeast Caribbean Sea, the Bahamas and Bermuda during the next day or two." Meanwhile, residents along the east coast of the U.S. should be on watch, starting Friday and over the weekend, as large swells will begin to affect areas of the coast. Rip tides may also be possible, so beachgoers and boaters should be aware of the hazardous conditions Bill will create along the coasts this weekend.

The National Hurricane Center in Miami, Fla. is forecasting Bill to pass to the west of Bermuda and then track parallel to the U.S. east coast over the weekend, stirring up the ocean.

Text credit: Rob Gutro/NASA's Goddard Space Flight Center



August 19, 2009

NASA's Aqua Satellite Gets Two Views of Category Four Hurricane Bill

AIRS image of Bill on Aug. 18, 2009> View larger image
AIRS captured Hurricane Bill's cold clouds with infrared imagery on August 18 at 12:35 p.m. EDT. The infrared revealed very cold high clouds, indicating a powerful hurricane. Credit: NASA JPL, Ed Olsen
Hurricane Bill has become a powerhouse in the Atlantic Ocean and NASA satellites are providing forecasters with important information to help their forecasts. Bill is now a category four hurricane on the Saffir-Simpson Scale and is expected to strengthen as it nears Bermuda, and NASA's Aqua satellite captured two views of his cloud cover.

On Wednesday, August 19, at 5 a.m. EDT, Bill's maximum sustained winds are near 135 mph, and hurricane force-winds extend out to 45 miles from Bill's large 35-45 mile-wide eye. Bill was closing in on the Leeward Islands, about 460 miles east of them, near 18.0 degrees north latitude and 54.9 west longitude. Bill continued to move west-northwest at 16 mph and had a minimum central pressure near 948 millibars.

NASA's Atmospheric Infrared Sounder (AIRS) instrument on the Aqua satellite captured Hurricane Bill's cold clouds with infrared imagery on August 18 at 12:35 p.m. EDT. The infrared revealed very cold high clouds, indicating strong thunderstorms and a powerful hurricane. Infrared imagery is useful to forecasters because it shows the temperature of the cloud tops, helping recognize if powerful thunderstorms exist in the storm. AIRS infrared imagery showed Bill's thunderstorm clouds are cold as or colder than 220 Kelvin or minus 63 degrees Fahrenheit (F)!

MODIS image of Bill on Aug. 18, 2009> View larger image
The MODIS instrument on NASA's Aqua satellite captured this stunning image of Hurricane Bill on August 18 at 2:40 p.m. EDT. Credit: NASA MODIS Rapid Response Team
Meanwhile, the Moderate Imaging Spectroradiometer, or MODIS instrument on Aqua satellite captured a stunning image of Hurricane Bill on August 18 at 2:40 p.m. EDT, clearly showing his large eye.

Bill's track has been the question on the minds of U.S. East Coast residents, and currently the models are indicating two different scenarios. According to the National Hurricane Center discussion this morning, August 19, "The track guidance models forecast Bill to gradually turn northwestward towards this weakness during the next 48-72 hours."

There's a large "deep-layer trough" – an elongated area of low pressure, associated with a cold front that is moving into the eastern United States, and forecasters think that front is going to push Bill eastward and curve him north and northeastward. Bill's track depends on the strength of the front and the timing, so one model calls for Bill to go near New England while other computer models have him taking a sharp turn out to sea. Forecasters and East Coast residents are hoping the front pushes Bill out to sea.

Text credit: Rob Gutro/NASA's Goddard Space Flight Center



August 18, 2009

TRMM image of Hurricane Bill's heavy rainfall over the Atlantic on August 17 > View larger image
TRMM captured Hurricane Bill's heavy rainfall on August 17 at 10:25 p.m. EDT. The yellow, green and red areas indicate rainfall between .78 to 1.57 inches per hour. Red areas are considered moderate rainfall.
Credit: NASA, Hal Pierce
NASA's TRMM Satellite Sees Wide-Eyed Hurricane Bill Strengthening

The TRMM satellite noticed a wide-eyed Hurricane Bill's rainfall is intensifying indicating he's getting stronger. Satellite images have also shown Bill's eye is widening.

NASA and the Japanese Space Agency's Tropical Rainfall Measuring Mission (TRMM) satellite flew over the center of Hurricane Bill on August 18, 2009 at 0225 UTC (August 17 at 10:25 p.m. EDT) capturing rainfall data.

TRMM rainfall images are false-colored with yellow, green and red areas, which indicate rainfall between 20 and 40 millimeters (.78 to 1.57 inches) per hour. Red areas are considered moderate rainfall.

The TRMM rainfall analysis from the TRMM Microwave Imager (TMI) and Precipitation Radar (PR) instruments reveal that hurricane Bill has an eye. This feature isn't apparent on the TRMM Infrared image (VIRS) but is evidence of Bill becoming a stronger category two hurricane with wind speeds increasing to about 85 knots (~98 miles per hour). In fact, satellite imagery shows that Bill's eye is quite large, between 35-45 nautical miles in diameter!

At 11 a.m. EDT, Hurricane Bill had maximum sustained winds near 105 mph, making him a Category Two on the Saffir-Simpson Scale. He is expected to strengthen into a Category Three hurricane, a major hurricane, with winds in excess of 110 mph. Bill was centered about 705 miles east of the Leeward Islands, near 15.9 north and 51.2 west. He was heading west-northwest near 16 mph with a minimum central pressure of 963 millibars.

Interests in the Leeward Islands should monitor Bill's progress, as his track is currently expected to remain at sea and sweep past them and head in a northwesterly direction over the next two days.

Text credit: Rob Gutro/NASA's Goddard Space Flight Center



August 17, 2009

The TRMM satellite flew over the large and well-organized Hurricane Bill. > View larger image
The TRMM satellite flew over the large and well-organized Hurricane Bill at 7:33 a.m. EDT on August 17 indicating bands of heavy rainfall.
Credit: NASA, Hal Pierce
Hurricane Bill on August 16 at 12:17 a.m. EDT (left) and August 17 at 1:50 a.m. EDT (right). > View larger image
This is a time series of two AIRS images of Hurricane Bill on August 16 at 12:17 a.m. EDT (left) and August 17 at 1:50 a.m. EDT (right) showing the cold temperatures in his thunderstorms, indicative of heavy rainfall.
Credit: NASA/JPL, Ed Olsen
Two NASA Satellites Captures Hurricane Bill's "Baby Pictures"

Bill was the third tropical depression in the Atlantic Ocean hurricane season, behind Ana and Tropical Depression One. Over the weekend Bill grew into the first hurricane in the Atlantic this season. Two NASA Satellites captured Bill's rainfall and cloud temperatures as he was powering up.

Hurricane Bill was upgraded to a hurricane by the National Hurricane Center (NHC) in Miami, Florida on August 17 at 5 a.m. EDT. The Tropical Rainfall Measuring Mission (TRMM) satellite flew over hurricane Bill a short time later at 1133 UTC (7:33 a.m. EDT) and captured Bill's "baby picture" shortly after he became a hurricane.

Data from the TRMM over flight was used in making the rainfall analysis at NASA's Goddard Space Flight Center in Greenbelt Md. The rainfall analysis showed that Bill was already a large and well- organized hurricane. TRMM's Microwave Imager and Precipitation Radar instruments revealed that Bill has bands of heavy rainfall.

NASA's Aqua satellite captured Hurricane Bill on August 16 at 12:17 a.m. EDT and August 17 at 1:50 a.m. with the Atmospheric Infrared Sounder (AIRS) instrument. AIRS measures cloud temperature using infrared light. In NASA's infrared imagery, the false-colored purple clouds are as cold as or colder than 220 Kelvin or minus 63 degrees Fahrenheit (F). The blue colored clouds are about 240 Kelvin, or minus 27F. The colder the clouds are, the higher they are, and the more powerful the thunderstorms are that make up the cyclone and Bill has some high thunderstorms.

On Monday, August 17 at 11 a.m. EDT, Bill continued strengthening and is expected to become a major hurricane - that is a Category Three hurricane, by Wednesday. Today, however, Bill had sustained winds near 90 mph, and the hurricane force winds extended 30 miles out from the center. Bill was moving west-northwest near 16 mph and had a minimum central pressure near 977 millibars. Bill was centered about 1,080 miles east of the Lesser Antilles, near 14.1 north and 45.2 west.

Bill is predicted by the NHC to become a dangerous category three storm in the next three days with winds of 110 knots (~126.5 miles per hour).

Text credit: Rob Gutro/NASA's Goddard Space Flight Center and Hal Pierce/SSAI
 
 
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http://www.nasa.gov/mission_pages/hurricanes/archives/2009/h2009_Bill.html