The warm ocean temperatures and weak winds recorded this past May were similar to those of May 2005—the year that spawned Hurricane Katrina.

Such patterns are "definitely ominous and foreboding," said Chris Hebert, lead hurricane forecaster for the private forecasting company ImpactWeather, based in Houston.

For instance, the similarities to 2005 means there's an increased risk of hurricane impact across the northern Caribbean islands, the Florida Peninsula, and the northeast Gulf Coast, from southeastern Louisiana to Florida, he said.

Even so, there's no guarantee 2010 will be the new 2005.

Meteorologists are also still stumped about "what made 2005 so special," Hebert noted. "We don't fully understand why the 2005 hurricane season, with 28 named storms, was more than twice as