U.S. National Oceanic and Atmospheric Administration on Thursday forecast a 85-per-cent chance of an "above- normal” 2007 Atlantic hurricane season, with 13-16 named storms and seven to nine hurricanes. A normal year brings six hurricanes, including two major ones, the agency said.

The climate patterns responsible for the expected above-normal 2007 hurricane season continue to be the ongoing multi-decadal signal (the set of oceanic and atmospheric conditions that have spawned increased Atlantic hurricane activity since 1995), warmer-than-normal sea surface temperatures in key areas of the Atlantic Ocean and Caribbean Sea, and the El Nino/La Nina cycle, according to Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA's Climate Prediction Center based in Camp Springs, Md.

"Today's El Nino/La Nina forecast from the Climate Prediction Center indicates a slightly greater than 50 percent probability that La Nina will form during the peak of the hurricane season. But more importantly, we are already observing wind patterns similar to those created by La Nina across the tropical Pacific Ocean and Caribbean Sea that encourage tropical cyclone development. The conditions are ripe for an above-normal season.” said Bell

Since the season began June 1, there have been three Atlantic named storms, slightly above average, NOAA said. Last year, there were 10 tropical storms in the Atlantic and just two made landfall in the United States.

August typically marks the start of the most frenetic months of Atlantic weather. The hurricane season ends November 30.