Dr. Rebecca Cheetham, European Model Development Team, Instrat®
Sixteen tropical storms formed during the 2008 season, compared to the 1950 to 2007 average of 9.7,1 an increase of 65 percent. The season also witnessed the first tropical cyclone ever to make four landfalls in one state (i.e., Hurricane Fay, impacting Florida). Hurricane Ike was dramatically larger than the modeling firms had expected in their event sets, and the discrepancy generated vastly different loss estimates that have yet to be resolved. Early indications for 2009 suggest another above-average tropical cyclone year.
The 2008 Atlantic tropical cyclone season displayed an above-average level of activity, producing a total of 16 named tropical cyclones, of which eight were hurricanes. Five became major hurricanes (i.e., Category 3 strength or higher on the Saffir-Simpson scale). The 2008 hurricane season was the fourth most severe since reliable records have been available. For the first time on record, six consecutive tropical cyclones (Dolly, Edouard, Fay, Gustav, Hanna, and Ike) made landfall on the U.S. mainland, and a record three major hurricanes (Gustav, Ike and Paloma) struck Cuba. It was also the first Atlantic season to have a major hurricane form in five consecutive months (July: Bertha, August: Gustav, September: Ike, October: Omar, and November: Paloma).
Verification of 2008 Atlantic Basin Tropical Cyclone Forecasts
Forecasts of tropical cyclone activity by Colorado State University have been issued for more than 20 years. For the 2008 North Atlantic basin, Philip J. Klotzbach and William M. Gray released forecasts on December 7, 2007, followed by updates in April, June, and August 2008. The table below shows their initial December 2007 forecast and the August 2008 mid-season update, compared to the observed numbers of tropical cyclones that developed in 2008. Prediction accuracy improved after spring meteorological conditions were observed, and forecasts made before early May are typically less accurate.
Forecasts for Atlantic tropical cyclones are also provided by Tropical Storm Risk (TSR) and WSI Corporation, a global provider of weather-driven business solutions. Their forecasts are displayed in the tables below.
- Julian Alovisi, Assistant Vice President, Instrat
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