NEW ORLEANS — The 2007 Atlantic hurricane season will probably be "very active" with 17 named storms, including nine hurricanes, five of them major, storm forecasters William M. Gray and Philip J. Klotzbach said Tuesday.
They said there was a 74% chance that a major hurricane, with sustained winds greater than 110 mph, would strike the U.S. coast between northern Maine and South Texas. That prediction is higher than the long-term average of 52%.
They also predicted a 50% chance that a major hurricane will hit the East Coast, including the Florida peninsula, while the long-term average is 31%.
The seasonal outlook by the two tropical weather specialists at Colorado State University is given careful consideration by meteorologists and emergency planners, but is hardly foolproof. Last year, Gray and Klotzbach overestimated the number of hurricanes.
If their forecast for 2007 holds true, it would mean a substantial jump in activity over the relatively quiet 2006 season, which saw 10 named storms, including five hurricanes, and was only the 12th year since 1945 that the nation escaped a hurricane strike.
But 2007 shouldn't be as busy as the 2004 and 2005 seasons, which combined saw eight hurricanes rake Florida, the forecasters said.
"The activity of these two years was unusual, but within the natural bounds of hurricane variation," said Gray, who pioneered long-range seasonal forecasting 24 years ago.
A normal season has about 11 named storms, including six hurricanes, with two intense.
The forecast, issued almost two months before the official June 1 start of the six-month season, is largely based on a faded El Nino, a condition that inhibits storm formation and that helped subdue tropical activity last year, Klotzbach said.
"When you have El Nino conditions during the hurricane season, it increases vertical wind shear across the tropical Atlantic and typically results in a weaker tropical cyclone season," he said.
Also factored into their 2007 prediction: abnormally warm waters in the tropical Atlantic, where hurricanes frequently begin.
Gray and Klotzbach call for 2007's tropical storm activity to be 185% of average. In comparison, 2005 saw 275% of average.
Gray said he overestimated his initial 2006 forecast because he didn't foresee El Nino arising.
This week, Gray and Klotzbach will attend the National Hurricane Conference in New Orleans to further explain their forecast.