The CSU research team is headed by Dr. William Gray, a pioneer in forecasting storm probabilities. It has had some success with accurate predictions in the past, though its forecast a year ago for the 2005 season was well off the mark.

It predicted 11 tropical storms and said six would become hurricanes. The season turned out to be a record-breaker with 26 storms, shattering the mark of 21 set in 1933.

Fourteen of the storms became hurricanes, including Epsilon, which continued to churn through the Atlantic with 75 mph (120 kph) winds southwest of the Azores on Tuesday at the tail end of the official season.

Katrina became the most expensive hurricane on record when it swamped New Orleans and the US Gulf coast in August, killing at least 1,300 people and causing at least $80 billion in damage.

The average season produces 9.6 storms, of which 5.9 become hurricanes and 2.3 are intense, or major, hurricanes. CSU said 2006 would again be well above average.

The probability of a major Category 3, 4 or 5 hurricane - the most destructive types - hitting somewhere on the US coast was 81 percent, the researchers said.

Florida, pounded by eight hurricanes in the last two years, had a 64 percent chance of being hit by a major storm.

Scientists say the Atlantic-Caribbean basin is in a period of increased hurricane activity, but CSU said future years were unlikely to see many seasons as intense as the last two, which together produced 41 storms.

"Even though we expect to see the current active period ... continue for another 15-20 years, it is statistically unlikely that the coming 2006 and 2007 hurricane seasons, or the seasons that follow, will have the number of major hurricane US landfalls as we have seen in 2004-2005," a news release said.

CSU researchers played down a theory offered by some scientists that global warming has contributed to the intensity of recent storms. Hurricanes are powered by warm sea water.