Early detection of tropical cyclones using SeaWinds-derived vorticity

A method of detecting the initial birth of tropical cyclones (TCs) in the Atlantic hurricane basin is developed using the SeaWinds scatterometer aboard the QuikSCAT satellite. The method is based on finding positive vorticity signals greater than a minimum size and magnitude within the swath of vector wind observations. The thresholds 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 from 18 August to 20 October 2000). For the 2000 research-quality data, 10 of 19 TCs are found an average of 23 hours before the National Hurricane Center classified them as TCs. For the near realtime data 5 of 13 TCs were found an average of 32 hours before. The SeaWinds scatterometer is a powerful new tool that will improve early detection of TCs.