2002 Annual

Monday, 14 January 2002: 9:30 AM
Early detection of tropical cyclones using SeaWinds-derived vorticity for the 2001 hurricane season
Ryan J. Sharp, COAPS, Florida State Univ., Tallahassee, FL; and M. A. Bourassa, J. J. O'Brien, K. B. Katsaros, and E. B. Forde
Poster PDF (256.9 kB)
A method for early detection of the systems that become tropical cyclones (TCs) in the Atlantic hurricane basin is developed using the SeaWinds scatterometer aboard the QuikSCAT satellite. The method is based on locating positive vorticity signals exceeding a minimum area and magnitude within the swath of vector wind observations. The thresholds applied herein are subjectively derived from the TCs of the 1999 Atlantic hurricane season. The thresholds are applied to two sets of data for the 2000 season: research-quality data and near-realtime (<3 hour delay) data (available starting 18 August 2000). For the 2000 research-quality data, 7 of 18 TCs had signals that were detected an average of 27 hours before the National Hurricane Center (NHC) classified them as tropical depressions. For the near-realtime data 3 of 12 TCs had signals that were detected an average of 20 hours before. The SeaWinds scatterometer is a powerful new tool that, in addition to other conventional products (e.g., satellite images that determine if convection is present), will help the NHC detect potential TCs earlier. The Center for Ocean and Atmospheric Prediction Studies at the Florida State University and the Hurricane Research Division at the Atlantic Oceanographic and Meteorological Laboratory are working to develop a prototype of this technique for operational use at the NHC. The results for the 2001 Atlantic and Eastern Pacific hurricane seasons will be discussed.

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