Storm Team Expects 8 Atlantic Hurricanes in '07
Date: 06-Aug-07
Country: US
Author: Jane Sutton
Of those, four would grow into major hurricanes of Category 3 or higher with winds over 110 mph (177 kph), the team founded by forecast pioneer William Gray said in its revised forecast.
The updated forecast was lower than the team's May 31 forecast for the six-month storm season that runs through Nov. 30, which had predicted 17 tropical storms, nine hurricanes and five major hurricanes.
The main reason for the reduced estimate was relatively cool sea surface temperatures, but the new numbers still represent an "above average" season.
The average season over the past 40 years, according to the US National Oceanic and Atmospheric Administration, had around 11 tropical storms, with six reaching hurricane wind speeds of 74 mph (119 kph) and two growing into major hurricanes.
The team led by Gray and researcher Philip Klotzbach did not count subtropical storm Andrea, which formed more than three weeks before the official June 1 start of the hurricane season but lacked the warm core and spinning thunderstorms of a tropical system.
The season has seen two named tropical storms, neither of which strengthened into a hurricane. Tropical Storm Barry brought much-needed rain to Florida in June and Tropical Storm Chantal formed in the north Atlantic on Tuesday and quickly died without threatening land.
The busiest part of the season is typically from August to mid-October.
The researchers said they lowered their forecast because conditions in the tropical Atlantic had grown less favorable for storm formation.
"Sea surface temperature anomalies have cooled across the tropical Atlantic in recent weeks, and there have been several significant dust outbreaks from Africa, signifying a generally stable air mass over the tropical Atlantic," Klotzbach said.
Hurricanes draw their strength from warmth and moisture, but dust in the air prevents the sun from heating the sea surface and dries out the atmosphere.
The researchers said there was a 68 percent chance that at least one major hurricane would hit the US coastline in 2007, with 43 percent chance that would happen on the US Atlantic Coast and 44 percent chance on the Gulf of Mexico coast.
Other private and government weather researchers have also predicted a more active season than average. But so far none have forecast anything like a repeat of record-breaking 2005, when 28 tropical storms spawned 15 hurricanes, including Katrina which flooded New Orleans and parts of the Gulf Coast.
None of the researchers accurately predicted last year's season, which was considered "average" but did not bring any hurricanes to the United States.
