A cooling of surface waters in the tropical Atlantic and the likelihood of a weak El Nino developing in the Pacific this summer have taken more wind out of the hurricane forecasts for the 2009 season, which began Monday.

Phil Klotzbach and William Gray, the hurricane experts at Colorado State University, today officially lowered their forecast for the coming season. They now expect hurricane activity slightly below the long-term averages. Tropical cyclone activity across the Atlantic Basin will be 90 percent of the average season, they said, compared with 160 percent in 2008.

Seasonal forecasts from Colorado State, AccuWeather.com and NOAA have been undercutting each other, and themselves, since December. Initial forecasts of an active season have been dialed back to slightly more-active than the average, to about average, and now to slightly less-active.

The revised Colorado State forecast, however, does not diminish by much the chances that at least one big hurricane will make landfall somewhere along the U.S. coastline. "The probability  ... is 48 percent compared with the last-century average of 52 percent," Klotzbach said. They rate the chance for a Cat. 3 storm making landfall along the East Coast (including Florida) at 28 percent this season, compared to a long-term average of 31 percent. (Those are wind and waves from Tropical Storm Hanna, pounding Ocean City in the 2008 photo above.)

Here are the CSU team's latest predictions, compared with their April forecast and long-term averages:

Latest: 11 named storms, including 5 hurricanes, of which 2 will reach "major" Cat. 3 status

April: 12 named storms, 6 hurricanes, 2 major

Average:  9.6 named storms; 5.9 hurricanes; 2.3 major 

For more on the team's forecasts for the coming season, click here.