Hurricane expert William Gray downgraded his forecast for the 2006 Atlantic storm season again Tuesday, predicting one more hurricane, two more named storms but no intense hurricanes.

The new report calls for a below-average hurricane season, with a total of six hurricanes and 11 named storms.

Gray and fellow Colorado State University researcher Philip Klotzbach cited El Nino conditions for the reduced number of storms.

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"August was inactive, but September had above-average activity," Klotzbach said. "We expect October to have below-average activity largely due to developing El Nino conditions in the central and eastern Pacific. November activity in El Nino years is very rare."

The long-term average for the June-through-November Atlantic hurricane season is 9.6 named storms, 5.9 hurricanes and 2.3 intense hurricanes, the forecasters said.

So far this season, the Atlantic basin has seen nine named storms and five hurricanes, the latest of them Issac, which broke up off Canada on Monday.

"Despite the lower predictions, residents living along the U.S. coastline should always be prepared for major storms," Gray said.

In the past two years alone, the researchers said, 13 major hurricanes formed in the Atlantic basin, and seven struck the U.S. coast, including the devastating Hurricane Katrina. By contrast, between 1995 and 2003, only three major hurricanes hit land.