Tuesday, 16 January 2007: 2:00 PM
Enhanced, high-density severe storm verification
217A (Henry B. Gonzalez Convention Center)
The Severe Hail Verification Experiment (SHAVE) was conducted during May through August of 2006. Researchers in SHAVE combined radar and environmental information available from the National Severe Storms Laboratory's Warning Decision Support System – Integrated Information (WDSS-II) with geographic information available in Google Earth and other sources. This information was used to identify locations to make targeted telephone calls to the public in regions where storms occurred within minutes of an event in order to collect information about the occurrence, size, and duration of hail. During the experiment, hail swaths from severe thunderstorms were documented at a much higher spatial and temporal resolution than is available in the National Climate Data Center's Storm Data publication and in National Weather Service (NWS) local storm report products.
The presentation shows results from SHAVE and compares the independently collected, high-resolution data with traditional NWS verification data for hail, and discusses the uncertainties associated with both data sets. We discuss the benefits of the improved verification data and their implications for warning verification and future changes in the NWS warning paradigm, such as “warning polygons” and probabilistic threat area warnings. We also consider improvements to the data collection methodologies and the expansion of the experiment in 2007 to include the analysis of severe wind events and other threats.