Tropical Storm Risk (TSR), the consortium of experts on insurance, risk management and seasonal climate forecasting led by UCL’s Benfield Hazard Research Centre, today increased.... Tropical Storm Risk (TSR), the consortium of experts on insurance, risk management and seasonal climate forecasting led by UCL’s Benfield Hazard Research Centre, today increased its forecast for Atlantic basin hurricane activity in 2005 by a further 30%. The forecast calls for record-breaking activity levels at sea, and for U.S. striking activity to be above-average to high probability though less severe than in 2004.

Based on current and projected climate signals, TSR’s updated forecast released today predicts Atlantic
basin activity to be record-breaking at 150% above-average and U.S. landfalling tropical cyclone activity to be 90% above-average. The prediction includes:

· A 100% (certain) probability of an above-normal Atlantic hurricane season.
· 22 tropical storms for the Atlantic basin as a whole, with eleven of these being hurricanes and seven
intense hurricanes
· An 85% (high) probability of an above-normal U.S. landfalling hurricane activity, a 15% likelihood of a
near-normal season and a 0% chance of a below-normal season
· Seven tropical storm strikes on the U.S., of which three will be hurricanes
· Three tropical storm hits, including two hurricanes on the Caribbean Lesser Antilles.

The predicted seasonal totals include the considerable activity which occurred during June and July (seven tropical storms and two intense hurricanes; three U.S. striking tropical storms of which one (Dennis) was a hurricane). If verified, the total of 22 tropical storms would be the highest ever recorded in a North Atlantic season.

TSR’s two predictors for hurricane activity at sea are the forecast July-September 2005 trade wind speed
over the Caribbean and tropical North Atlantic, and the forecast August-September 2005 sea surface
temperature (SST) in the tropical North Atlantic. The former influences cyclonic vorticity (the spinning up of storms) while the latter provides heat and moisture to power incipient storms. TSR anticipates both
predictors to have strong enhancing effects on activity in 2005. Only three hurricane seasons since 1950
(1955, 1995, and 1999) have had a trade wind speed higher than that forecast for 2005. The only year with an SST value higher than that foreseen for 2005 is 2004.