In our continuing work on the implementation and applications of an operational mesoscale modelling system dubbed "Deep Thunder", we examine its forecast performance for operations in the South Florida region. The Deep Thunder system has provided 24-hour forecasts for several metropolitan regions in the United States for a number of years. Model forecasts, are typically updated once or twice daily with nested grids down to 1 to 2 km resolution. Explicit, bulk cloud microphysics are included in the model predictions, to enable forecasts of potentially severe weather. The system was extended in October 2005 to provide forecasts for the Miami-Fort Lauderdale metropolitan area at 1.5 km resolution and all of southern Florida at 6 km resolution. All of the processing, modelling and visualization are completed in one hour on relatively modest hardware to enable sufficiently timely dissemination of forecast products for potential weather-sensitive applications.

In order to evaluate the quality of the forecasts produced by Deep Thunder at a storm-scale and its potential skill, we have focused on a number of interesting cases in which local convective development, regional coastal effects and systems of tropical origin impacted regions for which operational model forecasts are performed. We compare the model results with observational data and other available forecasts as well as the availability of specific forecast products for operational use. Such performance is examined by considering forecast timing, locality, intensity and structure of the events studied.