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Hurricane Season 2009: Tropical Depression Henri (Atlantic Ocean)
10.09.09
 
October 09, 2009

AIRS image of Henri> View larger image
NASA's Aqua satellite caught a visible image of Henri's (center) scattered remnant clouds on October 8 at 1:05 p.m. EDT located just east of the Leeward Islands. The larger area of clouds (bottom) is associated with another low pressure area affecting Venezuela. Credit: NASA JPL, Ed Olsen
Henri Now Disorganized, Forecasters Watching a Low Near Venezuela

The remnant clouds and thunderstorms that once belonged to Tropical Storm Henri show up on NASA satellite imagery as a disorganized area of cloudiness. South of where Henri's remnants are located, however, is an interesting area of disturbed weather approaching Venezuela.

NASA's Aqua satellite flew over the area of clouds and showers during the afternoon of October 8 and visible imagery revealed that the remnants Henri were disorganized. At that time Henri had weak low-level circulation, and any convection (rising air that forms thunderstorms) was removed from the center of the storm. When thunderstorms and showers become detached from a storm's low-level center it's an indication that the storm is waning. Henri's dying breath came around 5 p.m. EDT last night, October 8, when his sustained winds were last near 30 mph and they've weakened significantly since then.

By the morning of October 9, Henri's remnants were located about 200 miles northeast of San Juan, Puerto Rico. The remnants were producing disorganized thunderstorms. The northern Leeward Islands and Virgin Islands should anticipate 1-2 inches of rain.

The National Hurricane Center noted that Henri was done in by vertical wind shear and because the system is still in an unfavorable environment (still battling wind shear), regeneration is not expected.

Meanwhile, NASA's Aqua satellite also caught a glimpse of an area of disturbed weather associated with a tropical wave near the Windward Islands. That area of cloudiness has more form to it than Henri's remnants and its moving at a good clip, between 20-25 mph. The system did become less organized since late Thursday, and development into a tropical cyclone isn't expected in the next day or two as it interacts with Northern Venezuela over the weekend. Still, the National Hurricane Center gives it less than a 30 percent chance of development. It will be an area of interest over the weekend.

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



October 08, 2009

The image shows Henri as a disorganized area of clouds, located east of the Leeward Islands. > View larger image
NASA's GOES Project created an image of Tropical Depression Henri (top right) using data from the GOES-12 satellite on October 8 at 10:45 a.m. EDT. The image shows Henri as a disorganized area of clouds, located east of the Leeward Islands (the chain of islands left of Henri, running north to south). Puerto Rico and Hispaniola lit to Henri's west.
Credit: NASA GOES Project
NASA Satellite Reveals a Depressed and Disorganized Henri

Depression happens to everyone, even tropical storms, and Henri is now tropically depressed. NASA satellite imagery has confirmed he's weakened to a tropical depression and he is further expected to degenerate into a remnant low pressure area.

At 11 a.m. EDT on October 8, Henri's maximum sustained winds were down to 35 mph and waning. The National Hurricane Center used NASA's QuikScat satellite wind date from 6:12 a.m. EDT this morning to confirm Henri's wind speed.

His center was located 130 miles north-northeast of the northern Leeward Islands, near latitude 19.8 North and longitude 62.0 West. Tropical Depression Henri is moving toward the west near 13 mph and he's expected to slow down in the next day. Minimum central pressure is near 1010 millibars.

The Geostationary Operational Environmental Satellite known as GOES-12 covers the Atlantic Ocean, and is managed by the National Oceanic and Atmospheric Administration (NOAA). NASA's GOES Project, located at NASA's Goddard Space Flight Center, Greenbelt, Md. creates some of the GOES satellite images. An image created on October 8 at 10:45 a.m. EDT showed Henri as a disorganized area of cloudiness, located east of the Leeward Islands.

While on his westward track, Henri is expected to produce between 1 and 2 inches of rainfall over the northern Leeward Islands and the Virgin Islands.

Henri is likely to degenerate into a remnant low later today because he's in an environment of battering winds. Henri will remain in an environment of strong southwesterly shear today, and later winds from the northeast will hammer away at him, further weakening his circulation.

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



October 07, 2009

AIRS image of Tropical Storm Henri> Click for larger image
NASA's Aqua satellite AIRS instrument captured an infrared image of Tropical Storm Henri's clouds on October 7 at 1:29 a.m. EDT. Henri already had some strong convective activity in his center as indicated by high thunderstorms (in purple) that were as cold as -63F. Credit: NASA JPL, Ed Olsen
Henri Born in Eastern Atlantic…Could Be Short-Lived

Forecasters were watching a storm they designated as 91 yesterday, October 6, until it organized into a tropical cyclone east of the Leeward Islands around 5 p.m. EDT. It was then named "Tropical Storm Henri," the eighth named tropical cyclone of the Atlantic hurricane season.

On Wednesday, October 7 at 11 a.m. EDT, Henri had maximum sustained winds near 45 mph after reaching a peak sustained wind speed of 50 mph at 5 a.m. EDT today. Henri's center was located about 375 miles east of the Northern Leeward Islands, near 18.9 North and 57.4 West. Estimated minimum central pressure is 1007 millibars.

Henri is moving west-northwest near 15 mph and should continue in that direction for the next day before turning west. A subtropical ridge (an area of high pressure) over the Western Atlantic Ocean will be steering Henri over the next day or two. That area of high pressure will press Henri in a west or west-northwesterly direction. Over time, the ridge will become stronger, forcing Henri in a more westerly direction.

NASA's Aqua satellite AIRS instrument captured an infrared image of Henri's clouds on October 7 at 1:29 a.m. EDT. Henri already had some strong convective activity in his center as indicated by high thunderstorms (in purple) that were as cold as -63F.

The National Hurricane Center noted this morning, "Satellite imagery showed that the center of Henri has become exposed to the west of a mass of deep convection." In addition to the center being exposed, further weakening is likely due to increasing southwesterly wind shear over the next day or two.

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