Forecasters amend their hurricane predictions

FORT COLLINS, Colorado (CNN) -- Changing weather patterns have led forecasters to amend their hurricane predictions for the Atlantic Ocean this year, and now they predict a more intense season.

William Gray, a hurricane forecaster at Colorado State University, and his team of researchers released a forecast Thursday for the 2001 season calling for 12 named storms, seven hurricanes and three intense hurricanes -- those registering Category 3 or higher on the Saffir-Simpson scale.

In their initial storm forecast in December, the researchers predicted nine named storms, five hurricanes and two intense hurricanes. They raised the numbers slightly in an amended forecast in April.

"There were mixed signals this year," said Gray.

Among the reasons for the updated forecast, he said, was that the El Nino phenomenon in the Pacific was not proceeding as expected. El Nino, a warm body of water extending from the South American west coast north in the Pacific, can produce strong westerly winds that move across the Atlantic and rip the tops off developing storms.

Gray also cited above-average sea temperatures in the Atlantic Basin, which includes the North Atlantic, Caribbean Sea and Gulf of Mexico and below-average Atlantic trade winds, both of which promote hurricane activity. The team also forecasts above-average rainfall in West Africa, another reason for the amended prediction.

"All of the climate signals in the Atlantic Basin that we've been monitoring are very positive for above-average storm activity this year," Gray said.

The 2001 hurricane season extends from June 1 to November 30.

Gray also estimated a 69 percent chance that one or more major hurricanes would make landfall along the U.S. coast during in 2001. The past century's average is 52 percent.

He forecast a 50 percent chance of landfall along the East Coast and Florida peninsula, where the past century's average is 31 percent, and a 39 percent chance of landfall along the Gulf Coast, where the average is 30 percent.

One factor for landfall, he said, is warmer, saltier water making its way to the northern Atlantic. The heavier, saltier water sinks, warming the Atlantic and giving storms a greater chance to develop into a hurricane.

"Even with the increased forecast numbers, this won't be one of the worst seasons of the century," Gray said, "but we are anticipating an active season not unlike several of the most recent years."

Since 1995, 79 named storms, 49 hurricanes and 23 major hurricanes have occurred in the Atlantic Basin, Gray said. Three of the 23 major hurricanes have made landfall in the last six years.