Meteorological Setting for a Catastrophic Event: The Deadly Joplin Tornado of 22 May 2011

Abstract

The tornado that struck Joplin, MO on 22 May 2011 resulted in the first triple-digit death toll from a single tornado in the United States since the 1950s. This paper documents the meteorological setting for this exceptional event, as no published studies have done so yet. Synoptic-scale surface and upper air maps, a brief radar overview, environmental parameters via the SPC mesoanalysis and soundings, and mesoscale surface analysis are used to examine the background setting that led to the deadly tornado. Several other tornado days in the same general area with synoptic patterns similar to the Joplin tornado day also are examined from the standpoint of environmental parameters for comparison. The results show the Joplin tornado case to be an example of very supportive ingredients developing from a favorable evolution of synoptic-scale features; similar patterns have produced several deadly tornadoes in recent years. A couple of mesoscale boundaries also may have contributed to increased tornado potential in the Joplin area. Informal comments published elsewhere have described the environment for this event as “unfavorable” for violent tornadoes. The findings here contradict and refute that characterization, and show that the background environment for the Joplin tornado was actually quite favorable for supporting strong or violent tornadoes.