Applications of Warn-on-Forecast for Flash-Flood Producing Extreme Convective Rainfall Events

The National Oceanic and Atmospheric Administration's (NOAA) National Severe Storms Laboratory (NSSL) is working towards developing a prototype Warn-on-Forecast (WoF) system with the goal to incorporate NWP model based probabilistic forecast guidance in National Weather Service severe weather warning decision process. The technology and science that is currently under development to achieve WoF goals will improve short-term forecasts of high impact hazardous convective weather threats like low-level mesocyclones, extreme rainfall, large hail and damaging winds. As part of this project, an experimental prototype WoF system is developed using the WRF-ARW model and NOAA GSI-EnKF data assimilation software and assimilates NWS conventional observations, WSR-88D reflectivity, radial velocity and geostationary satellite cloud water path (CWP) retrievals. This presentation will demonstrate the capability of the prototype WoF system in predicting high impact weather with a focus on flash flood producing extreme rainfall events using retrospective short-term (0-6 h) probabilistic ensemble forecasts from several recent record-breaking events. To evaluate how the frequent-update-cycle forecast system performs in predicting these events, we will use both qualitative and quantitative verification metrics.