Modeling southwest Florida tornadoes

Predicting tornado development near the complex coastline of urban Lee and Charlotte counties in Southwest Florida is challenging, especially with regard to air and land transportation. Four warm season cases from coastal southwest Florida showing striking similarities in tornado development were modeled at 1 km and higher resolutions using the Weather Research and Forecasting Model. Each case featured dominant southeast flow with Gulf Coast sea breezes developing during the afternoons. The sea breezes are a focusing mechanism for moisture pooling and provide initial lift. The model results depicted similar cyclonic mesocirculations seen in observed surface data. Those circulations lead to enhanced convection with strong updrafts capable of supporting tornadogenesis. The results of this modeling study show that ambient flow, moisture distribution, and the degree of instability were important factors in the timing of various interactions that led to tornado development. These modeling scenarios provided great insight for forecasters in forecast and warning operations for severe weather.