Towards Better Operational Predictions of High-Impact Winter Weather in the Northern High Plains
Winter storms in the High Plains, esp. Wyoming, 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. We report on a new joint initiative between several NWS Forecast Offices, the NOAA/ESRL HRRR
(High-Resolution Rapid Refresh) development team, and the University of Wyoming 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. Specific elements of this project
include (a) validation of HRRR forecasts for extreme surface wind speeds and wind gusts near complex terrain; (b) real-time,
HRRR-based prediction of extreme winds and cross-winds down to the highway and airport runway level; (c) development of a
physically based blowing snow product as well as a snow squall product, built on HRRR output, and an examination of the
accuracy of the HRRR forecasts in terms of the occurrence and intensity of blowing snow and snow squalls; (d) fine-scale
real-time HRRR-based prediction of blowing snow and snow squalls; and (e) assessment of the value of higher-resolution
(1 km) convection-permitting HRRR-like WRF simulations in terms of potential improvements in the forecast of strong wind
events, snow squalls, and blowing snow.
The 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 will serve as an invitation for the broader weather forecast community in the High Plains to join and test the products as they come online.