Tropical Cyclone Forecasting Applications of the GOES WMSI

Abstract

The Geostationary Operational Environmental Satellite (GOES) sounder-derived Wet Microburst Severity Index (WMSI) was originally developed and implemented to assess the potential magnitude of convective downbursts over the central and eastern continental United States. The WMSI algorithm incorporates convective available potential energy (CAPE), to parameterize static instability, as well as the vertical theta-e (equivalent potential temperature) difference (TeD) between the surface and mid-troposphere to infer the presence of a mid-level dry air layer. It has been noted with two recent landfalling hurricanes over the Florida Gulf of Mexico coast that the GOES WMSI product accurately predicted downburst magnitude associated with convective bands and the remnant eye wall. As a convective system, it is expected that tropical cyclones can be profilic downburst producing storms. In fact, several severe downbursts were observed in association with the pre-hurricane squall line and remnant eye wall of Hurricane Charley (August 2004) and the remnant eye wall of Hurricane Wilma (October 2005).