The chances of a below-normal hurricane season have increased to 90% from 70%, the National Oceanic and Atmospheric Administration's Climate Prediction Center said Thursday. The 90% probability of a below-normal season is the highest confidence level given by the center since seasonal hurricane outlooks began in 1998, the center said in a statement. Researchers warned, however, that this is no guarantee that a hurricane won't hit the United States this season. “Tropical storms and hurricanes can and do strike the United States, even in below-normal seasons and during El Niño events,” Gerry Bell, the center's lead seasonal hurricane forecaster, said in the statement. “Regardless of our call for below-normal storm activity, people along the Atlantic and Gulf coasts should remain prepared and vigilant, especially now that the peak months of the hurricane season have started.” The updated outlook also lowers the overall expected storm activity this season. It now includes a 70% percent chance of six to 10 named storms, compared with six to 11 in the initial May outlook, of which one to four could become hurricanes, up from three to six in May, and zero to one could become major hurricanes, up from zero to two in May. Researchers cited a strengthened El Niño, associated atmospheric conditions such as strong vertical wind shear and enhanced sinking motion across the tropical Atlantic and Caribbean Sea, and below-average tropical Atlantic sea-surface temperatures as the three primary factors for the below-normal season. Earlier this week, researchers at Colorado State University reiterated their forecast for a below-average hurricane season.
The National Oceanic and Atmospheric Administration (NOAA) has predicted that there is a 90% chance of a below-normal hurricane season for 2015. NOAA also predicts the possibility of an above-average El Niño event in 2015, which could lead to more intense hurricanes hitting U.S. shores.