Active Atlantic hurricane season seen

WASHINGTON (Reuters) - The 2007 Atlantic hurricane season will be more active than normal due to warmer ocean waters, with as many as ten hurricanes, and three to five of them could be major, the U.S. government's top climate agency predicted on Tuesday.

"We are right now in ... a period of more active hurricane seasons," said Conrad Lautenbacher, head of the National Oceanic and Atmospheric Administration. "It just takes one hurricane to make it a bad year for everyone here."

NOAA foresees 13 to 17 tropical storms this season, with seven to 10 developing into hurricanes. Three to five could be major ones of Category 3 or higher with winds over 110 mph (177 kmh), the agency said in its annual forecast.

An average Atlantic hurricane season brings 11 tropical storms, of which six reach hurricane wind speed of 74 mph (119 kph), including two major hurricanes, NOAA said. The hurricane season, which officially starts on June 1, typically peaks between August 1 and late October.

Earlier forecasts for the season also have predicted the return of an active pattern this year. A year ago, just 10 storms formed and no major hurricanes reached the United States.

The 2007 season got off to an early start this month when subtropical storm Andrea formed off the U.S. Atlantic Coast, making it the first named storm of the year.

In the devastating 2005 Atlantic hurricane season a record four major hurricanes hit the United States, including Katrina, which devastated New Orleans, killed 1,300 people and caused $80 billion in damage. The 2005 season generated 28 tropical storms, of which 15 became hurricanes.

The storms also slammed U.S. offshore oil and natural gas platforms and shut coastal refineries, sending fuel prices to then-record highs.

LA NINA THREAT

Weather forecaster AccuWeather.com has predicted 13 or 14 tropical storms or hurricanes would form in the Atlantic this year and six or seven could hit the United States, with the Gulf Coast and Gulf of Mexico oil installations at high risk.

The Colorado State University team under forecast pioneer William Gray predicted 17 storms, of which nine would become hurricanes. WSI Corporation and London-based Tropical Storm Risk also have predicted an active season.

Gerry Bell, a top NOAA forecaster, said while it was not possible to predict how many hurricanes might make landfall in the United States this year, similar seasons have seen between two and four storms hit the U.S. Atlantic and Gulf coasts.

But he said La Nina conditions could develop in the eastern Pacific in the next one to three months, adding to the likelihood of above-average hurricane activity.

La Nina, which means "little girl" in Spanish, is an abnormal cooling of ocean surface temperatures in the equatorial Pacific. El Nino, or "little boy," has the opposite effect.

"If La Nina develops, storm activity will likely be in the upper end of the predicted range, or perhaps even higher depending on how strong La Nina becomes," said Bell.

NOAA will update its hurricane outlook in early August.