The NSSL Experimental Warn-on-Forecast System for Ensembles at the 2018 NOAA Hydrometeorology Testbed Experiments

The NOAA National Severe Storms Laboratory (NSSL) in collaboration with other NOAA and university partners, is leading the Warn-on-Forecast (WoF) program to develop and refine an ensemble-based, convection-resolving model forecast system that will potentially fill the National Weather Service forecast guidance gaps within the ‘watch-to-warning’ temporal and spatial scales for high impact weather. The result is the development of a prototype WoF system called the NSSL Experimental Warn-on-Forecast System for ensembles (NEWS-e), which is a frequently cycled, regional-scale, on-demand ensemble data assimilation and prediction system. Toward this end, the NEWS-e system is being evaluated in real time at the Hazardous Weather Testbed Spring Forecast Experiments (HWT SFE) for hazardous severe weather. However, one important application of NEWS-e is the short-term forecast guidance for flash flood producing extreme rainfall events. To evaluate the utility of WoF probabilistic products for extreme rainfall and flash flood forecast guidance, the NEWS-e system is demonstrated at the NOAA Hydrometeorology Testbed Flash Flood and Intense Rainfall (HMT-FFaIR) and Multi-Radar Multi-Sensor (MRMS) Hydro (HMT-Hydro) experiments in the summer of 2018 for the first time. This talk will provide an overview and evaluation of the NEWS-e probabilistic products, in addition to ensemble verification results from the 2018 HMT experiments.