Two updated forecasts for the 2013 Atlantic Hurricane Season slightly reduce the number of named storms expected this year, but there is no change in outlook for another above-average season.
The National Hurricane Center released its August update calling for an above average hurricane season of 13-19 named storms, including 7-9 hurricanes and 3-5 major hurricanes. In May, NHC forecast 13-20 named storms, including 7-11 hurricanes and 3-6 major hurricanes. The weather service says there is a 70 percent probability of each of the ranges of activity.
Factors causing the increased intensity are reduced trade winds over the Caribbean Sea and the tropical North Atlantic through September, which will influence cyclone activity in the Atlantic. Also, forecasters expect Atlantic sea surface temperatures to be slightly above normal.
Aon Benfield’s research unit Tropical Storm Risk (TSR) slightly reduced its prediction to 15 named storms, seven hurricanes and three major hurricanes.
In June, TSR predicted 16 named storms, eight hurricanes and three major hurricanes this season. Still, the season is poised to be stronger than the historic norm.
TSR says an average year produces 11 named storms, six hurricanes and three Category 3 and above hurricanes of sustained winds of 111 mph or higher on the Saffir-Simpson Scale. TSR scientists project that there is about a 50 percent probability the 2013 Atlantic Hurricane Season Accumulated Cyclone Energy (ACE) Index will be above-average, a 41 percent likelihood it will be near-normal, and a 10 percent chance it will be below-normal.
To date, four named storms have popped up in the Atlantic reaching tropical storm status and doing little damage.