The NSSL Experimental Warn-on-Forecast System for Ensembles (NEWS-e) at 2018 NOAA Hydrometeorology Testbed

Excessive rainfall from severe thunderstorms can cause extensive flash flooding and threaten the lives of people living in the affected area. The Weather Prediction Center’s (WPC) MetWatch desk is responsible for issuing Mesoscale Precipitation Discussions that are designed to enhance near-term 1–6 hr situational awareness for regions where heavy rainfall may lead to flash flooding. To aid WPC’s MetWatch desk and Weather Forecast Office forecasters in predicting heavy rainfall and flash flood, a cycled, regional, on-demand convective-scale ensemble data assimilation and prediction system (NEWS-e) is developed using the Warn-on-Forecast concept with the support from NOAA Office of Weather and Air Quality FY2016 Joint Technology Transfer Initiative funded grant. The ensemble system has the capability to assimilate ground-based remote sensing boundary layer observations (i.e. AERI and Doppler Lidar), GOES-R Advanced Base Imager clear sky radiance and cloud water path, MRMS reflectivity and WSR-88D radial velocity in addition to routinely available traditional observations. The 0–6 h probabilistic forecast products from the NEWS-e system is evaluated at the NOAA Hydrometeorology Testbed Flash Flood and Intense Rainfall (HMT-FFaIR) experiment at WPC during June-July of 2018. This talk will provide an overview of NEWS-e probabilistic products, in addition to ensemble verification results from the HMT-FFaIR experiments. Some areas requiring further development and improvement of the ensemble system as identified during the testbed experiment will also be discussed.