The Preconvective Environment of Summer Thunderstorms over the Florida Panhandle

Abstract

The preconvective environment of summer thunderstorms over the Florida Panhandle is investigated. Geostationary satellite imagery as well as surface and radiosonde data were examined during the summers of 1990 and 1991. Days were classified either as synoptically disturbed or undisturbed based on the imagery. The undisturbed days then were subjectively subdivided into those having strong, weak, or no convection. Composite sounding profiles of various meteorological parameters were constructed for each category of the undisturbed days. Composites of various stability indexes also were calculated. Midtropospheric moisture (particularly from 700 to 500 mb) and low-level instability were the best thermodynamic parameters for forecasting convection over the Florida Panhandle. The surface-based lifted index was the most useful stability index for predicting convective development. Wind direction also was related to the degree of convective activity in the Florida Panhandle. The strong convection days tended to have low-level winds from the south or southwest. Low-level winds on the driest days generally had northerly and easterly components.