Towards Better Operational Predictions of High-Impact Winter Weather in the Northern High Plains and Rockies

Winter storms in the High Plains and northern Rockies often produce hazardous conditions for travelers, and impacts of high winds, blowing snow, and snow squalls continue to result in numerous road closures, chain-reaction pile-up crashes, and truck blow-overs each year. The intensity and duration of these high-impact events remain poorly predicted, yet the impact of better forecasts on lives saved and commerce is significant. A joint initiative between several NWS Forecast Offices, the NOAA/ESRL HRRR (High-Resolution Rapid Refresh) development team, and the University of Wyoming, funded through a NOAA CSTAR (Collaborative Science Technology, and Applied Research) grant, aims to provide more specific, useful, and precise forecasts of high-impact winter weather in the region, building on the 3-km resolution HRRR model output. Examples of hazardous conditions due to extreme winds, blowing snow, and snow squalls will be shown. The initial focus is on the validation of HRRR forecasts for extreme surface wind speeds and wind gusts near complex terrain, as well as the validation of model-derived blowing snow conditions and simulated snow squalls. As part of this effort, the snow squall parameter recently developed based on the New England climatology is assessed for the High Plains. The project will deliver real-time, HRRR-based prediction of extreme winds and cross-winds down to the highway and airport runway level, a blowing snow intensity product and a snow squall product, all built on HRRR output, and designed for operational use. Real-time HRRR-like WRF simulations at finer resolutions (~1 km) will be considered for operational use. The ultimate objective is broad accessibility of this applied model guidance, incl. by means of a web portal with user-friendly hazardous weather forecasts on zoomable Google maps with color-coded highways. We hope to also involve Departments of Transportation in affected states. This talk also serves as an invitation for the broader weather forecast community in affected regions to test the HRRR-based products as they come online.