Featured Images

Hurricane Season 2009: Tropical Storm Danny (Atlantic)
08.30.09
 
August 30, 2009

GOES-12 satellite this morning, August 30, caught remnants from Danny exiting Newfoundland (top right). > View larger image
The GOES-12 satellite this morning, August 30, caught remnants from Danny exiting Newfoundland (top right) and Hurricane Jimena on the Mexican west coast, and Tropical Storm Kevin farther west (bottom left) this morning at 7:45 a.m. EDT.
Credit: NASA/GOES Project
Danny's Remnants Exit Newfoundland, Jimena and Kevin Active in Pacific

While Danny's remnants exit Newfoundland, Canada this morning, Jimena has become a powerful Category Three hurricane in the Eastern Pacific, and Tropical Storm Kevin developed to her west.

The Geostationary Operational Environmental Satellite, or GOES-12, operated by NOAA, caught remnants from Danny exiting Newfoundland and Hurricane Jimena on the Mexican west coast, and Tropical Storm Kevin farther west this morning at 7:45 a.m. EDT. NASA's GOES Project created imagery from the GOES-12 satellite that clearly shows Danny's clouds stretched from the Mid-Atlantic north to New England. The image also shows a powerful Hurricane Jimena with a clear eye, and a less intense Tropical Storm Kevin.

Danny merged with a low pressure area yesterday and brought rains to Long Island, eastern Massachusetts, coastal New Hampshire and Maine, before moving into Nova Scotia, and Newfoundland, Canada. On Sunday morning, August 30, the rains associated with what was Danny are exiting Newfoundland. Live Environment Canada radar reveals the rains: http://www.weatheroffice.gc.ca/radar/index_e.html?id=ERN.

At 9 a.m. EDT this morning, Jimena's center was located about 305 miles south of Cabo Corrientes, Mexico near 16.0 north and 105.7 west. She had maximum sustained winds near 115 mph. She was moving northwest near 12 mph. Minimum central pressure is near 965 millibars, a drop of 25 millibars in 24 hours indicating rapid intensification. The National Hurricane Center noted "interests in western Mexico and the southern Baja California Peninsula should monitor the progress of Jimena."

Farther to her west, the second area of low pressure forecasters were watching on Friday has developed into Tropical Storm Kevin. He had sustained winds near 50 mph, and is forecast to strengthen. He's located about 995 miles southwest of the southern tip of Baja California, near 14.1 north and 121.9 west. Kevin was north at 7 mph and had a minimum central pressure of 1000 millibars.

Now that Danny is history. there is one new area in the Atlantic that forecasters are watching for likely development, located 950 miles east of the Windward Islands. This area has a greater than 50 percent chance of development, according to the National Hurricane Center.

Text credit: Rob Gutro, NASA/Goddard Space Flight Center



August 29, 2009

GOES-12 satellite this morning, August 29, saw a dying Danny on the U.S. east coast (top right). > View larger image
The GOES-12 satellite this morning, August 29, saw a dying Danny on the U.S. east coast (top right) and an explosive Tropical Storm Jimena on the Mexican west coast (bottom left).
Credit: NASA/GOES Project
NASA Sees Dying Danny Drenching Eastern New England, Jimena Exploding in Pacific

Weekends and tropical cyclones have gone together this hurricane season, and this weekend, Danny is dying in the Atlantic, while Jimena has exploded in fast development in the eastern Pacific Ocean.

Danny is in the process of being absorbed by an extra-tropical low pressure area over North Carolina, and has lost his punch in terms of sustained winds. Danny has been downgraded to a tropical depression this morning, Saturday, August 29. However, he's still packing a lot of heavy rain, and bringing dangerous surf along the U.S. east coast from the Mid-Atlantic to the Northeast into Canada.

Danny's heavy rainfall is mostly located to the north and northeast of the storm, as evidenced in NASA satellite data. As he continues merging with the extra-tropical low pressure system today, his center will stay off-shore and keep moving north. Ahead of his center, heavy rains will pour over eastern Long Island, eastern Massachusetts, coastal New Hampshire and Maine, before moving into Nova Scotia, Canada.

When the Tropical Rainfall Measuring Mission satellite (managed by NASA and JAXA) flew over tropical storm Danny yesterday, August 28, it revealed that only moderately heavy rain was occurring then in an area northeast of Danny's center of circulation. That also holds true today, August 29 as Danny is now raining on the northeastern U.S. On the radar, Danny's rainfall looks like a large "V" shape entering New England.

For live radar from Boston, Massachusetts, go to: http://radar.weather.gov/radar.php?rid=BOX&product=NCR&overlay=11101111&loop=yes.

Dangerous surf is the other issue Danny is causing. Beachgoers should not venture into the ocean, as Tropical Depression Danny is stirring up surf 3-5 feet high in the mid-Atlantic. Surf is much higher, as much as 6-10 feet, near Long Island, N.Y., and coastal Rhode Island, Connecticut, and south and east-facing Cape Cod, Massachusetts.

At 5 a.m. EDT today, Saturday, August 29, the National Hurricane Center in Miami, Fla. issued its last advisory on Tropical Depression Danny. At that time, Danny's remnants had sustained winds near 35 mph, and he was moving north-northeast near the same speed! Danny's center was located 540 miles south-southwest of Nantucket, Mass.; or 80 miles southeast of Cape Hatteras, North Carolina. He had an estimated minimum central pressure near 1007 millibars.

The Geostationary Operational Environmental Satellite, or GOES-12, operated by NOAA, caught a dying Danny on the U.S. east coast and an explosive Tropical Storm Jimena on the Mexican west coast this morning at 7:45 a.m. EDT. NASA's GOES Project created imagery from the GOES-12 satellite that clearly shows Danny's clouds stretched from the Mid-Atlantic north to New England. The image also shows a powerful Tropical Storm Jimena that developed early this morning.

Tropical Storm Jimena developed from one of the two areas that forecasters were watching yesterday. It developed and intensified quickly and by 8:18 a.m. this morning, Saturday, August 29, she had maximum sustained winds near 70 mph. Light upper level winds and warm sea surface temperatures are fueling her intensification.

At 9 a.m. EDT this morning, Jimena's center was located about 270 miles southwest of Acapulco, Mexico near 14.2 north and 102.8 west. She was moving west near 10 mph and will turn north-northwest in the next day or so. Minimum central pressure is near 990 millibars. Jimena is expected to become a hurricane later today.

Text credit: Rob Gutro, NASA/Goddard Space Flight Center



August 28, 2009

Tropical Storm Danny as the large area of clouds of the southeast U.S. coast. > View larger image
On August 28 at 9:32 a.m. EDT, GOES-12 captured Tropical Storm Danny as the large area of clouds of the southeast U.S. coast.
Credit: NASA/GOES Project
Danny had some high, strong thunderstorms in the center of his circulation on August 28 at 2:17 a.m. EDT > View larger image
AIRS imagery revealed that Danny had some high, strong thunderstorms in the center of his circulation on August 28 at 2:17 a.m. EDT, indicating he was still holding onto tropical storm status with powerful convection.
Credit: NASA/JPL, Ed Olsen
Tropical Storm Danny Forecast to Follow Close to Bill's Path

Last week, Hurricane Bill moved north parallelling the U.S. East Coast, and that's currently what forecasters at the National Hurricane Center are expecting for Tropical Storm Danny. Danny's forecast track also takes him near eastern North Carolina, by eastern Massachusetts and into Nova Scotia, Canada, just as Bill did. NASA's Aqua satellite and NOAA's GOES-12 satellite are providing forecasters with valuable data about Danny.

As Tropical Storm Danny is poised to continue its northern track, paralleling the U.S. East Coast tropical storm watches are posted for the North Carolina coast from Cape Lookout northward to Duck, including the Pamlico and Albemarle Sounds. Interests elsewhere from the Carolinas northward to New England and the Canadian Maritimes should monitor the progress of Danny. More watches and warnings may be posted later today, August 28.

At 8 a.m. EDT, Danny was still hanging onto tropical storm status, with sustained winds near 40 mph. He's located about 355 miles south of Cape Hatteras, North Carolina, near 30.1 north and 75.2 west. Danny is moving north-northwest near 9 mph, and he's expected to shift north and speed up later today. The estimated minimum central pressure is 1008 millibars.

The Atmospheric Infrared Sounder (AIRS) flies on NASA's Aqua satellite and captures infrared images of tropical cyclones take the temperatures of thunderstorm's cloud top temperatures to determine their strength.

How does infrared imagery know how high clouds are in the sky? The coldest ones are higher in the sky (because in the troposphere, the lowest layer of atmosphere where weather happens, temperatures fall the higher up you go until you get to the stratosphere).

The highest clouds are as cold as or colder than 220 Kelvin or minus 63 degrees Fahrenheit (F) and second highest level of 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. AIRS imagery revealed that Danny had some high, strong thunderstorms in the center of his circulation on August 28 at 2:17 a.m. EDT, indicating he was still holding onto tropical storm status with powerful convection.

Another satellite that NASA uses is the Geostationary Operational Environmental Satellite, or GOES. GOES-12 covers the Atlantic Ocean, and is managed by NOAA. On August 28 at 9:32 a.m. EDT, GOES-12 captured Tropical Storm Danny as the large area of clouds of the southeast U.S. coast.

Danny is a big storm with tropical storm force winds extending 410 miles in diameter. He's expected to pass offshore of the outer banks of North Carolina early Saturday. Residents in eastern North Carolina and up and down the U.S. East Coast should be aware that Danny, like Bill last week, is producing large and dangerous surf and life-threatening rip currents.

Text credit: Rob Gutro, NASA/Goddard Space Flight Center



August 27, 2009

Still from Danny movie > View video
NASA's GOES Project created a movie of satellite data from August 25-27 showing the progression of Tropical Storm Danny from a low near Bermuda to his status as a tropical storm.
Credit: NASA/GOES Project, Dennis Chesters
Tropical Storm Danny Stars in a GOES Satellite Movie

NASA's GOES Project has been busy with animating satellite imagery of Tropical Storm Danny, and has created a movie of him from August 25-27.

The short movie includes still imagery from the National Oceanic and Atmospheric Administration's (NOAA) Geostationary Operational Environmental Satellite (GOES) called GOES-12, monitors weather conditions over the U.S. east coast. NASA's GOES Project, located at NASA's Goddard Space Flight Center in Greenbelt, Md. creates imagery and animations from GOES-12 data, and created the movie.

The movie begins with an image on August 25 when Danny was just a low pressure area, east of the Bahamas and not yet named. The movie continues through Danny's formation and classification as a tropical storm during the morning of August 26, to the beginning of its journey up the U.S. East Coast today, August 27 at 2:25 p.m. EDT.

Danny's maximum sustained winds at 11 a.m. EDT today, August 27 were near 60 mph, and slow strengthening is expected. He was located near 27.5 north and 73.1 west, or 550 miles south-southeast of Cape Hatteras, North Carolina. Danny is moving northwest near 13 mph, and is expected to turn north. Danny had a minimum central pressure near 1006 millibars.

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/Goddard Space Flight Center



Tropical Storm Danny off the Bahamas on August 26 at 2:30 p.m. EDT. > View larger image
The MODIS instrument on NASA's Aqua satellite captured this view of Tropical Storm Danny off the Bahamas on August 26 at 2:30 p.m. EDT.
Credit: NASA/MODIS Rapid Response Team
NASA Satellite and Aircraft Data See Danny's Center Reform Farther North

NASA satellite imagery and aircraft data revealed Tropical Storm Danny's center reformed a little farther north than it was yesterday. The center of his circulation is "broad and elongated" so it's been somewhat challenging to pinpoint his center. The National Hurricane Center used NASA QuikScat data to confirm winds early this morning. From QuikScat data, they determined that "Danny does not have a typical tropical cyclone structure and has most of the strong winds located well north and east of the center."

Another of the satellites in NASA's fleet that provides helpful imagery is the Aqua satellite and its Moderate Resolution Imaging Spectroradiometer (MODIS). MODIS captured an image Danny at 2:30 p.m. EDT yesterday, August 26. Satellite imagery and aircraft data since that time confirmed that Danny's center is now near 27.4 north and 72.1 west. That's about 370 miles east-northeast of Nassau or 575 miles south-southeast of Cape Hatteras, North Carolina.

Danny's maximum sustained winds near 5 a.m. EDT this morning, August 27 were near 60 mph, but slow strengthening is expected. After all, Danny is near the Gulf Stream flow along the east coast. Danny is moving northwest near 10 mph, and is expected to turn north. Danny had a minimum central pressure near 1006 millibars.

The computer forecast models that the National Hurricane Center uses are "in excellent agreement on a turn toward the north on Friday as Danny moves between a ridge (an elongated area of high pressure) over the western Atlantic Ocean and a shortwave trough (an elongated area of low pressure, like a cold front) over the southeastern United States."

Text credit: Rob Gutro, NASA/Goddard Space Flight Center



August 26, 2009

The AIRS instrument provided valuable infrared data on Danny, indicating some strong thunderstorms. > View larger image
The Aqua satellite also flew over Tropical Storm Danny today, August 26, at 2:29 a.m. EDT and the AIRS instrument provided valuable infrared data on his cloud top temperatures, indicating some strong thunderstorms.
Credit: NASA/JPL, Ed Olsen
NASA Sees Tropical Storm Danny Form, U.S. East Coast on Watch

An area of low pressure east of the Bahamas has now powered up into Tropical Storm Danny, and NASA's Aqua satellite captured his strengthening thunderstorms in infrared imagery. Danny came together this morning, August 26, and was classified as a tropical storm at 11 a.m. EDT.

The National Hurricane Center said this morning that "interests in the Bahamas and the southeastern United States should monitor the progress of Danny."

Danny's sustained winds went from less than 35 mph to 45 mph this morning, and some slow strengthening is possible in the next couple of days. Danny's center was about 445 miles east of Nassau and about 775 miles south-southeast of Cape Hatteras, North Carolina. That's near 24.9 north and 70.3 west. Danny's minimum central pressure was near 1009 millibars. He was moving west-northwest near 18 mph and is expected to turn to the north-northwest on Friday, headed to the U.S.

Forecasters at the National Hurricane Center (NHC) used wind data from NASA's QuikScat satellite this morning to confirm Danny's tropical storm status. The NHC discussion today said, "Quikscat data and a few observations from the stepped frequency microwave radiometer show tropical storm-force winds occurring north and northeast of the center...which is the basis for the initial intensity of 40 knot winds."

Danny is a medium-sized storm, with tropical storm force winds extending 140 outward from his eye. In comparison, Tropical Storm Hilda's tropical storm force winds extend only 70 miles out from the center. Hilda is currently in the Central Pacific Ocean, moving south of the Hawaiian Islands.

The Aqua satellite also flew over Tropical Storm Danny earlier today, August 26 at 2:29 a.m. EDT and the Atmospheric Infrared Sounder (AIRS) instrument provided valuable infrared 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 the data helped forecasters see there are strong thunderstorms in Danny's center of circulation.

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.

The National Hurricane Center notes that "Danny is expected to cause storm total rainfall of 2 to 3 inches with maximum amounts of 4 inches over the central and northwestern Bahamas. Total rainfall of 1 to 2 inches is expected over the southeastern Bahamas and the Turks and Caicos Islands.".

Text credit: Rob Gutro, NASA/Goddard Space Flight Center