Continuing warmth in Atlantic surface waters and the dissipation of El Nino conditions in the Pacific will combine to bring the U.S. a "very active" hurricane season in 2007, according to hurricane forecasters at Colorado State University. That is, busier than last year, when no hurricanes made U.S. landfall, but not as active as 2004 and 2005, when storms pummeled Florida and devastated New Orleans and the Gulf Coast. (That's 2005's Katrina at left.)

The CSU forecasting team of Phil Klotzbach and William Gray today boosted the numbers they forecast in December for the upcoming Atlantic hurricane season, citing the faster-than-expected disappearance of the El Nino conditions in the Pacific. They're now anticipating 17 named storms between June and November, besting the long-term average of 9.6. Of those 17 storms, the forecasters expect nine will grow to hurricane strength (The average is 5.9.) Five of those will become Category 3 storms or stronger. (The average is 2.3.)

The CSU forecast also predicts a 74 percent chance one of those major hurricanes will strike somewhere along the U.S. Coast, higher than the average of 52 percent for the past century. There is a 50 percent chance one will hit somewhere on the East Coast, including Florida, more than the 31 percent average for the last century. And, there is a 49 percent chance the Gulf Coast will see a storm that big, the forecast states, up from the long-term average of 30 percent.

Here is the full report. Looking back, Klotzbach and Gray fell far short of predicting 2005's record hurricane season, but so did everyone else. Their forecasts in December 2005, April and June 2006 also badly over-estimated the actual storm counts in last year's season. That season fizzled, meteorologists say, because of the unanticipated development of El Nino conditions in the Pacific, and dust storms from North Africa that blew out over the eastern tropical Atlantic.

This year, Klotzbach and Gray anticipate neutral, or weak-to-moderate La Nina conditions in the Pacific, which would support hurricane formation in the Atlantic. The Atlantic basin also continues to experience unusually warm surface waters, which is another factor supporting hurricane formation. The Atlantic Basin has seen unusually active hurricane seasons in most years since 1995 thanks to warm water conditions there, the CSU team says. That trend, part of a long-term Atlantic climate cycle, is likely to continue for decades to come.

Unlike many climate scientists, Klotzbach and Gray say there is insufficient scientific evidence that global warming is playing a role in the recently heightened hurricane activity in the Atlantic. Their reasoning can be found in their current forecast.