Evaluating the Performance of NSSL’s Experimental Warn-on-Forecast System using the METplus Verification Scorecard

The NOAA National Severe Storms Laboratory’s (NSSL) Warn-on-Forecast System (WoFS) is a convection allowing model (CAM) ensemble that is designed to provide probabilistic guidance of high-impact weather hazards within the NWS watch-to-warning time scale (0-6 h). The WoFS is targeted for regional domains of interest where forecasted severe weather and/or flash flooding risks are defined by the Storm Prediction Center’s (SPC) Day 1 convective outlook and the Weather Prediction Center’s (WPC) Day 1 Excessive Rainfall Outlook, respectively. To assess how WoFS performs compared to other operational CAMs in a quick and efficient manner, this study develops a verification scorecard using the community-based Model Evaluation Tools (METplus) software suite under the Unified Forecast System framework. A time-lagged High Resolution Rapid Refresh ensemble (HRRR-TLE) is created for the comparison with WoFS. Datasets from the NSSL’s Multi-Radar/Multi-Sensor System (MRMS) are used as verification to compare the models to several fields including hourly QPF and composite reflectivity. This study will sample cases from both springtime severe convective events as well as summertime heavy rainfall events. The results will be summarized and presented at the conference.