A GIS-based analysis of supercell and squall line occurrence across Oklahoma

Severe local storms, in particular supercell and squall lines, pose a threat to life and property due to their attendant hazards of high winds, torrential rainfall, lightning, hail, and tornadoes. While the process of forecasting such storms is extremely important, it is highly beneficial to review past occurrences of such events over a multi-year period to determine high and low frequency regions. By partitioning storm occurrence by months, weeks, or even days, it is possible to quantify how high and low frequency regions vary spatially and temporally. Using Geographic Information Systems (GIS) spatial analyses, this study examined the geographic distribution of supercell and squall line storms identified via radar for several hundred cases observed across Oklahoma beginning in 1994. The results of the study include high-resolution analyses of typical storm motion by month, geographic high-frequency regions, and spatially-averaged storm initiation locations.