"As a property owner, the seasonal outlook makes no difference in your preparation plans," Feltgen said. Even if there is just one storm, "if it hits you, it's a bad year."
Forecasters have had a tough time with their hurricane predictions in recent years. In last year's April forecast, Klotzbach and Gray correctly predicted an "active" season. But their forecast of 17 named storms, including nine hurricanes and three "major" storms, was too high.
By the season's end, there had been 15 named storms, with six making it to hurricane strength. Only two became major storms, although both of those -- Dean and Felix -- made landfall as fearsome Category 5 hurricanes, killing more than 160 people in the Caribbean, Mexico and Central America.
Forecasters overestimated the storm activity in 2006 by even more. And they badly underestimated the ferocious pace of storms in 2005.
The 2005 season spawned 27 named storms and 15 hurricanes -- twice what Gray and Klotzbach had predicted in April. The storms included Katrina and Rita, which devastated New Orleans and other Gulf Coast communities from Texas to Alabama.
Natural cycles
Forecasters say the long-term, natural cycles in air pressure and sea-surface temperatures in the Atlantic, which became more favorable for storms beginning in 1995, will continue to bias the system in favor of busier-than-average hurricane seasons for 15 to 20 years to come.
"We don't attribute this to anything humans are doing," Gray said. "These are natural" cycles.
Klotzbach and Gray said that while their old forecast models had done well prior to 1994, they've been less reliable since then. The forecasters blamed a "discontinuation" of statistical links between West African rainfall and other atmospheric factors.
"We do not yet have a good explanation for as to why these relationships failed," they said.
This year they've rolled out another scheme based on Atlantic sea-surface temperatures and atmospheric pressure gradients over the ocean. Applied to past seasons, it predicted better than the April forecasts in 11 of the 13 years studied.
This year's CSU forecast also uses an "analog" technique, which looks for years with comparable ocean and atmosphere conditions, and notes how those hurricane seasons turned out.
The scientists found four comparable years -- 1950, 1989, 1999 and 2000. "All four of those years had well above-average hurricane activity," Klotzbach said.
frank.roylance@baltsun.com
Hurricane names
Here are the hurricane names for the 2008 Atlantic season.
Arthur
Bertha
Cristobal
Dolly
Edouard
Fay
Gustav
Hanna
Ike
Josephine
Kyle
Laura
Marco
Nana
Omar
Paloma
Rene
Sally
Teddy
Vicky
Wilfred
[Source: National Hurricane Center
