January 22nd, 2009

Atlantic Basin Tropical Cyclone Forecasts for 2009

Posted at 1:00 AM ET

Dr. Rebecca Cheetham, European Model Development Team, Instrat®

Colorado State University

On December 10, 2008, Philip J. Klotzbach and William M. Gray at Colorado State University released their forecast for the 2009 season, making predictions for somewhat above-average activity in the North Atlantic basin (based on the average 1950 to 2000 season). The team also predicted an above-average probability that a major hurricane (Category 3 to 5 on the Saffir-Simpson scale) would make landfall on the U.S. coastline at some point during the 2009 season.

Tropical Storm Risk

Tropical Storm Risk’s (TSR’s) extended range forecast for 2009 Atlantic Basin Hurricane activity was released on December 5, 2008. TSR anticipates another active Atlantic hurricane season in 2009, with Atlantic basin and U.S. landfalling tropical cyclone activity forecast to be 35 percent above the 1950 to 2008 norm in 2009. The forecast spans the period from June 1, 2009 to November 30, 2009 and uses data through the end of November 2008. TSR’s main predictors are the forecast July 2009 to September 2009 trade winds over the Caribbean and tropical North Atlantic, and the forecast August 2009 to September 2009 sea surface temperature in the tropical North Atlantic. The TSR forecast, together with predicted numbers of tropical storms and hurricanes making U.S. landfall are summarized in the table below.

WSI Corporation

WSI Corporation also released its 2009 hurricane forecast on December 24, 2008. WSI predicts that 13 named storms, 7 hurricanes, and 3 intense hurricanes will develop in 2009.1 These forecast numbers are all higher than the 1950 to 2008 averages of 9.8 named storms, six hurricanes, and 2.5 intense hurricanes. WSI said the forecast for an active 2009 season are due to the expected continuation of warmer-than-normal Atlantic Ocean temperature anomalies into next summer and the likelihood of a favourable or neutral wind shear environment associated with the lack of an El Nino event.

Additional Contributor:


  1. WSI Corporation

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