Experimental activities were designed to test the utility of unique convective storm output fields (such as simulated reflectivity, updraft helicity and speed, vertically integrated graupel, and surface wind speed) from various deterministic models and the SSEF in a simulated operational forecasting environment. This was accomplished through the issuance of daily real time probabilistic severe weather forecasts valid for late afternoon and evening time periods, and next day subjective evaluations. Preliminary forecasts were issued in the morning utilizing guidance from 00 UTC experimental models including probabilistic guidance from the SSEF, supplemented by operational model guidance and observational data. A final updated forecast was issued by mid-afternoon incorporating later model runs (especially the hourly High Resolution Rapid Refresh HRRR) and observational data.
A number of focused evaluation tasks were designed to help identify specific sensitivities of model performance, such as the impact of radar and other data assimilation on convective forecasts, and model storm sensitivity to horizontal resolution and microphysics parameterizations, and to assess the utility of various statistical processing approaches and creation of probabilistic storm guidance from the SSEF. Descriptions of the daily severe storm experimental forecasting and evaluation activities are presented, including findings on model performance and potential value of experimental guidance products to operational severe storm forecasting.