The Challenges of Issuing Operational One-Hourly Severe Weather Probabilities

The Hazardous Weather Testbed (HWT) Spring Forecast Experiment (SFE) is held each spring at the National Weather Center in Norman, OK. This annual five week forecast exercise is a joint effort between the National Severe Storms Laboratory (NSSL) and the Storm Prediction Center (SPC). Meteorologists from different disciplines and locations (modelers, academia, NWS field office forecasters, etc.) come together in an attempt to accelerate the transfer of new research directly into operations. This experiment also identifies new initiatives for operationally relevant research and examines the effectiveness of the ever changing, but improving Convection Allowing Modeling systems (CAMs). The primary emphasis for the 2014 SFE was creating probabilistic severe weather forecasts for shorter time periods than currently issued by the SPC. Two forecasts desks were established during this SFE, with one desk issuing separate 3-hourly forecasts for hail, wind and tornadoes, and the other desk issuing nine 1-hourly total severe weather probabilities. This document will discuss the 1-hourly forecast issuances and challenges. The 1-hourly forecast and reasoning, as well as verification, for May 21st in the Ohio Valley will also be presented to illustrate the forecast complexities for issuing 1-hourly forecast. Lastly, the recommendations for overcoming the forecast and logistical challenges of issuing this product in an operational environment are discussed