The Atlantic hurricane season will be exceptionally active this year, according to a British forecasting group, raising the possibility that killer storms like Hurricane Katrina could again threaten the United States.
London-based forecaster Tropical Storm Risk on Tuesday said the six-month season, which begins on June 1, was expected to bring 17 tropical storms, of which nine will strengthen into hurricanes with winds of at least 74 miles per hour.
Four of those are expected to become more destructive "intense" hurricanes, TSR said.
The long-term average for the Atlantic is for 10 storms to form during the hurricane season and for six of those to reach hurricane strength.
The United States emerged unscathed from the 2006 season after it spawned a below-average nine storms, of which five became hurricanes. Experts had universally — and erroneously — predicted 2006 would be a busy year for Atlantic storms.
None of the hurricanes hit the United States, bringing welcome relief to beleaguered residents of the U.S. Gulf Coast, where Katrina killed 1,500 people, swamped New Orleans and caused about $80 billion in damage the year before.
But TSR said current and projected climate signals indicate that Atlantic basin and U.S. landfalling hurricane activity will be 75 percent above the 1950-2006 average in 2007.
TSR had predicted in December that Atlantic basin and U.S. landfalling hurricane activity would be just 60 percent above average this year. It raised the projected activity level because of the sudden dissipation in February of last year's El Nino weather phenomenon.
An unusual warming of the eastern Pacific waters, El Nino events tend to suppress Atlantic storm activity.
Other experts, including hurricane forecast pioneer Dr. William Gray and his team at Colorado State University, have also warned that the 2007 hurricane season is likely to be busier-than-average.
The relative calm of last year's hurricane season, which forecasters had mistakenly predicted would be busy, came on the heels of a record 28 storms and 15 hurricanes in 2005 and only a slightly less furious season in 2004.