Evaluating high-resolution configurations of the WRF model that are used to forecast severe convective weather: The 2005 SPC/NSSL Spring Experiment

The 2005 SPC/NSSL Spring Program will be conducted over a seven-week period during the peak severe convective season, from mid April through early June. The primary focus of this program will be an examination of three different near-cloud-resolving (dx = 2-4 km) configurations of the WRF model in a simulated severe-weather-forecasting environment. These configurations, covering approximately the eastern three-fourths of the U. S., will be evaluated based on their ability to 1) simulate the evolution of the pre-convective environment, particularly boundary layer evolution, temperature and moisture stratification, and vertical wind profiles; 2) predict the location and timing of thunderstorm initiation and evolution; and 3) offer useful information on thunderstorm morphology with an emphasis on higher order classifications of discrete supercells and quasi-linear convective systems (QLCS).

Model evaluation procedures will be based on both subjective and objective verification strategies. Subjective approaches will rely on the concept of consensus assessment by expert operational forecasters and research scientists. Panels of experts will be anchored by SPC forecasters and NSSL scientists and will include a diverse group of researchers and forecasters from numerous meteorological centers and universities. Objective methods will include traditional metrics such as equitable-threat and bias scores as well as object-oriented approaches that are currently under development. The goal of both approaches will be to provide specific information to model developers that can guide their efforts to improve various components of the WRF model.

Results from the model evaluation will be presented at the conference.