The Severe Hail Verification Experiment

This presentation highlights preliminary results from the Severe Hail Verification Experiment (SHAVE), which is a project that blends high-resolution radar data with geospatial information. The primary objective of this experiment is to collect high temporal and spatial resolution data that describe the distribution of hail sizes in hail swaths produced by severe thunderstorms. These data enable several goals, including: (1) to utilize the high-resolution verification data in the development of techniques for probabilistic warnings of severe thunderstorms, (2) to evaluate the performance of a multi-sensor, multi-radar hail detection algorithm, (3) to correlate changes in the hail size distribution with storm evolution, and (4) to enhance climatological information about hail in the United States. The high spatial and temporal resolution of the dataset collected during the project facilitates the development of decision-making tools that improve forecasts and warnings of severe hail as well as improving the historical record of hail events. The project runs approximately May 15, 2006 through August 15, 2006. It utilizes the real-time hail swath products from the CONUS Warning Decision Support System – Integrated Information (WDSS-II) to enhance data collection via verification telephone calls to select data points along a storm's path immediately following storm passage. Because the presence of hail is diagnosed via radar on the scale of the continental United States, it is possible to collect data from anywhere in the contiguous 48 states on a daily basis throughout the summer, which minimizes project "down days." Data are collected by a team of University of Oklahoma meteorology students working closely with scientists from the National Severe Storms Laboratory/Cooperative Institute for Mesoscale Meteorological Studies. SHAVE is an experiment conducted in the NOAA Hazardous Weather Testbed as part of the Experimental Warning Program by the NSSL/CIMMS Severe Weather Warning Applications and Technology Transfer (SWAT) group.