As 2007 Atlantic Hurricane Season Ends, Questions Remain

WASHINGTON, Nov. 29 /PRNewswire-USNewswire/ -- As the 2007 Atlantic hurricaneseason officially comes to a close on November 30, NOAA scientists arecarefully reviewing a set of dynamic weather patterns that yieldedlower-than-expected hurricane activity across the Atlantic Basin. As a result,the United States was largely spared from significant landfalling storms.However, several noteworthy events took place, including two back-to-backCategory 5 hurricanes hitting Central America and the rapid near-shoreintensification of the single U.S. landfalling hurricane.

(Logo: http://www.newscom.com/cgi-bin/prnh/20041022/DCF003LOGO )As a whole, the 2007 Atlantic hurricane season produced a total of 14 namedstorms, including six hurricanes, two of which became major hurricanes. NOAA'sAugust update to the seasonal forecast predicted 13 to 16 named storms - ofwhich seven to nine would be hurricanes, including three to five majorhurricanes of Category 3 strength or higher. An average season has 11 namedstorms, with six becoming hurricanes, including two major hurricanes. "The 2007 Atlantic hurricane season produced the predicted number of namedstorms, but the combined number, duration and intensity of the hurricanes didnot meet expectations," said Gerry Bell, Ph.D., lead seasonal hurricaneforecaster at NOAA's Climate Prediction Center. "The United States wasfortunate this year to have fewer strong hurricanes develop than predicted.Normally, the climate patterns that were in place produce an active, volatilehurricane season."The climate patterns predicted for the 2007 hurricane season - an ongoingmulti-decadal signal (the set of oceanic and atmospheric conditions that havespawned increased Atlantic hurricane activity since 1995) and La Nina -produced the expected below-normal hurricane activity over the eastern andcentral Pacific regions. However, La Nina's impact over the Atlantic wasweaker than expected, which resulted in stronger upper-level winds andincreased wind shear over the Caribbean Sea during the peak months of theseason (August-October). This limited Atlantic hurricane formation during thatperiod. NOAA's scientists are investigating possible climate factors that mayhave led to this lower-than-expected activity.All in all, one hurricane, one tropical storm and three tropical depressionsstruck the United States: Tropical Depression Barry came ashore near TampaBay, Fla., on June 2; Tropical Depression Erin hit southeast Texas on August16 and Tropical Depression Ten came ashore along the western Florida panhandleon Sept. 21; Tropical Storm Gabrielle hit east-central North Carolina on Sept.9, and Hurricane Humberto hit the upper Texas coast on Sept. 13. Also this year, the U.S. was reminded of the dangers of inland flooding. "Texas and Oklahoma experienced deadly flooding when Erin dumped up to 11inches of rain. Fresh water flooding is yet another deadly aspect of tropicalcyclones," said Ed Rappaport, acting director of NOAA's National HurricaneCenter.Other noteworthy statistics of the season include:

-- Eight storms formed in the Atlantic Basin during September - tying-- Eight storms formed in the Atlantic Basin during September - tyingSeptember 2002 for having the most storm formations during any given month.

-- For the first time in recorded history, two Category 5 hurricanes made-- For the first time in recorded history, two Category 5 hurricanes madelandfall in the Atlantic Basin during the same season. Hurricane Dean hit theYucatan Peninsula near Costa Maya on Aug. 21 with 165 mph winds, followed byHurricane Felix on Sept. 2, near Punta Gorda, Nicaragua, with 160 mph winds.

-- With a central pressure of 906 millibars, Hurricane Dean had the third-- With a central pressure of 906 millibars, Hurricane Dean had the thirdlowest pressure at landfall - behind the Labor Day 1935 Hurricane in theFlorida Keys and Hurricane Gilbert of 1988 in Cancun, Mexico. Dean is also thefirst Category 5 hurricane to make landfall in the Atlantic Basin sinceHurricane Andrew hit South Florida in 1992.

-- Hurricane Humberto grew from a tropical depression with top winds of 35 mph-- Hurricane Humberto grew from a tropical depression with top winds of 35 mphinto a hurricane with winds of 85 mph within 24 hours - only three othersstorms (Celia 1970, Arlene and Flora 1963) intensified faster during a 24-hourperiod from below tropical storm strength.

-- NOAA's Climate Prediction Center will release an official summary of the-- NOAA's Climate Prediction Center will release an official summary of the2007 Atlantic Hurricane Season in January 2008. NOAA will announce its 2008hurricane outlooks for the Atlantic, East Pacific and Central Pacific in May. NOAA's Atlantic and East Pacific hurricane outlooks are official products ofits Climate Prediction Center in collaboration with scientists at the NationalHurricane Center, Hurricane Research Division and the HydrometeorologicalPrediction Center. NOAA's Central Pacific Outlook is an official product ofthe Central Pacific Hurricane Center in Honolulu, Hawaii, and in collaborationwith the Climate Prediction Center. On the Web:NOAA: http://www.noaa.govNOAA's National Hurricane Center: http://www.hurricanes.govNOAA's National Weather Service: http://www.weather.govSOURCE NOAACarmeyia Gillis of NOAA, +1-301-763-8000, ext. 7163