Case study of hurricane Wilma's wind structure evolution using HWRF

Tropical cyclone (TC) wind structure evolution is currently neither well understood nor well forecasted. TCs with similar intensity can have greatly different radius of maximum wind, radius of hurricane-force winds, and the inner-core kinetic energy (for example, as measured by 0-200 km area integrated kinetic energy from aircraft flight level data). The structural variability is influenced by various mechanisms both within the storm and its surrounding environment. These variations can have substantial repercussions with respect to storm impact. Therefore, it is important to correctly model the wind structure evolution as well as the mechanism influencing these changes. Objective analyses of the flight-level winds from Hurricane Wilma (2005) will be used to evaluate the wind structure evolution in HWRF model simulations of the storm. Wilma was chosen because it underwent large structural variations during its lifetime. Specifically, a comparison of the inner-core kinetic energy versus intensity (maximum wind) for the HWRF forecasts to that from the aircraft analyses will serve to assess the accuracy of the HWRF model. This may also facilitate a better understanding of the important factors contributing to TC wind structure evolution.