Severe Weather Threat Discrimination in Southeast Oregon and Southwest Idaho using Pre-storm Environmental Data

This study will seek to determine if pre-storm environmental data, available to operational meteorologists in real time, can differentiate between environments that favor the production of hail, wind, tornado, or some combination of these threats. Our area of study is southeast Oregon and southwest Idaho, an area far removed from typical severe weather studies. To accomplish this, we have examined all recorded severe weather reports across southeast Oregon and southwest Idaho for the period from 1955 to 2005. The reports have been paired with a representative sounding from KBOI (Boise, ID) in those cases where the report and the sounding are within about 3 hours and 100 nm of each other (following the methodology of Brooks and Craven, 2002, and Ramsey and Doswell, 2005, among others). Furthermore, the reports have been separated into the following categories: hail; wind; tornado; or multiple threat. Numerous parameters have been calculated from these soundings. Using these categories and parameters, we will determine whether we can differentiate between severe weather threats on a monthly or seasonal basis. We will also present findings from a study of 500 HPa and surface pressure charts from these severe weather days. We will attempt to determine patterns which favor severe weather in these areas, and to determine if patterns can differentiate between severe weather threats. This work is currently under way, and sufficient progress has been made to ensure that findings can be complete in time for the extended manuscript deadline.