Convection Associated with Warm-Season Stationary Fronts East of the Rocky Mountains

While substantial research exists on the relationship between severe weather and warm/cold fronts, less work has been completed on this relationship with stationary fronts (SFs). Thus, this presentation explores the relationship between SFs and severe weather events east of the Rocky Mountains. A total of 275 SFs lasting 24-48 hours were chosen from a nine-year warm-season climatology of SFs for analysis.

It was found that the majority of 24 to 48-hour SFs result in fewer than 50 total severe reports. The average number of reports per SF event was 78 reports. Wind reports were by far the most common type of severe report in the vicinity of SFs with 13618 reports, while there were 6722 hail reports, and only 1059 tornado reports. Both wind and hail reports occurred most frequently in June and the least frequently in September.

The nine Gallus et al. (2008) storm types were used to categorize all precipitation systems that were responsible for the SPC storm reports shown in this study. Precipitation echoes in the vicinity of each SF were categorized as BE: Bow Echo, BL: Broken Line, CC: Cluster of Cells, IC: Isolated Cells, LS: Leading Stratiform Squall Line, NL: Nonlinear System, None: No available radar image, NS: No Stratiform Squall Line, PS: Parallel Stratiform Squall Line, TS: Trailing Stratiform Squall Line. Results indicate that TS were the most frequent occurring storm type associated with severe weather reports along a SF, followed by CC and IC. LS proved to be the most uncommon storm type.