Tuesday, 13 January 2004
Tornadic Supercell Outbreaks in the Southern Great Plains
A modeling case study was carried out for the tornadic supercell outbreaks that occurred on the successive days May 8 and 9, 2003. In addition, a limited climatology was performed from 1998 to 2003 on Southern Great Plains tornadic supercell outbreaks. Using all available data, including National Weather Service Weather Surveillance Radar (WSR-88D) data, Oklahoma Mesonet data, Atmospheric Radiation Measurement (ARM) data, and satellite-derived data, the preliminary climatology was established. The climatology, which will be added to each year as an ongoing activity, is based on Galway’s (1977) definition of a tornadic outbreak which states that an event is considered an “outbreak” if the event consisted of 10 or more tornadoes associated with the same synoptic system.
The current NCAR/Penn State Mesoscale Model (MM5) and the Center for Analysis and Prediction of Storm’s (CAPS) Advanced Regional Prediction System (ARPS) model were run during the May 8-9, 2003, outbreak over the Southern Great Plains. The ARPS model had commenced running in real-time mode, and the MM5 model was applied to the archived operational data. An analysis of the models’ performance in predicting the tornadic supercells revealed some encouraging results, especially for the May 8 event. The model results will be presented in detail at the meeting.