Weather Forecasting with MM5

The Florida Division of Forestry is now running the PSU/NCAR mesoscale model version 5 (MM5) daily (0 UTC) to produce high resolution weather forecasts. DOF's configuration of MM5 currently features a 21 km grid which is used for 48 hour forecasts, in addition a 7 km nested grid that provides a more detailed 24 hour forecast. Forecast products are supplied through surface and upper air maps, as well as soundings and cross sections for selected locations. Soundings and 21 km maps are available every 6 hours over a 48 hour period while the 7 km maps and cross sections are available every 2 hours for 24 hours. Soundings display vertical profiles of temperature, moisture and winds while the cross sections display vertical slices of wind, relative humidity and equivalent potential temperature.

Model Configuration: MM5 is currently configured with a nested grid (21 km/7 km) with 34 vertical levels. The model is initialized using data from the National Center for Environmental Prediction's ETA model analysis and forecast fields. Parameterizations include:

• MRF planetary boundary layer scheme

• Explicit moisture (including simple ice physics)

• Kain-Fritsch cumulus parameterization