NWC REU 1998



Effects of Shortwave Troughs and Tornado Formation

Jamie Casto and Charles Doswell



Anecdotal forecaster experience has long suggested an association between shortwave troughs and tornadoes. In this study, this association is explored by examining 500 mb charts for all the shortwave troughs meeting certain criteria and considering their association with significant tornado (F-2 and greater) occurrences during May of 1957 and May of 1987. It was found that only 15% of shortwave troughs produce a significant tornado during their existence, but that most significant tornadoes (~25%) are associated either with a significant shortwave trough or with a synoptic-scale cut-off cyclone.

Paper available upon request.