Previous subjective verification exercises have focused on mesoscale models with parameterized deep convection. During the 2003 Spring Program, convection resolving numerical forecasts were included for the first time. In particular, explicit predictions of convection were generated with the WRF model, using a relocatable domain with 3 km grid spacing that was centered over the area of most concern to the SPC on a daily basis. Over this same domain, these high-resolution WRF forecasts were subjectively verified and compared with forecasts from 4 different mesoscale models: a coarser resolution configuration of WRF (12 km grid spacing), the operational Eta model, the EtaKF (an experimental version of the Eta routinely used at the SPC), and the new non-hydrostatic mesoscale model (NMM).
Each day the different models were evaluated and assigned verification ratings based on their predictions of convective activity, with an emphasis on severe convection. Furthermore, the two versions of the WRF model were compared on an hourly basis for three specific characteristics of convective activity: timing of initiation, convective evolution, and convective mode (e.g., isolated cells vs. convective lines, etc.).
Several important inferences can be drawn from the resulting subjective verification dataset. The data provide unique information about the value of model output to human forecasters, information that cannot be gleaned from summaries of traditional verification measures. The results have important implications for tailoring model output to best suit the needs of operational forecasters.