"The probability of another Katrina-like event is very small," said Phillip Klotzbach, lead forecaster for the hurricane research team.
The researchers reduced the number of likely hurricanes from nine to seven and intense hurricanes from five to three.
There is, however, a considerably higher-than-average probability of at least one intense hurricane making landfall in the United States this year, 73 percent. The average is 52 percent.
Researcher William Gray said Atlantic Ocean surface temperatures are not quite as warm and surface pressure is not quite as low, both factors in the decision to revise the forecast.
"Overall, we think the 2006 Atlantic basin tropical storm season will be somewhat active ... ," Klotzbach said. "This year it looks like the East Coast is more likely to be targeted by Atlantic basin hurricanes than the Gulf Coast, although the possibility exists that any point along the U.S. coast could be affected."
Gray and his team says hurricane activity will continue to be above average for another 15 to 20 years.
The National Hurricane Center in Miami in May predicted 16 named storms in the Atlantic, six of them major hurricanes. As of Thursday, there have been three named storms.
Thirteen major hurricanes have formed in the Atlantic Basin the past two years, seven of them striking the U.S. coast with devastating damage resulting from four of them in 2005: Dennis, Katrina, Rita and Wilma.
Klotzbach and Gray call for a total of 15 named storms to form in the Atlantic basin this year, down by two from their prediction May 31. On average, there are 9.6 named storms, 5.9 hurricanes and 2.3 intense hurricanes per year.
For Florida and the East Coast, the probability of a storm landfall is 64 percent, compared with a long-term average of 31 percent.
From the Florida Panhandle eastward to Brownsville, Texas, the probability is 26 percent, compared with a long-term average of 30 percent.