Thunderstorm Wind in Bon Homme County, South Dakota

Thunderstorm wind gusts were measured by the South Dakota Mesonet site 3 miles east of Avon.

A deep mid-level trough over the northwestern U.S. ejected a leading wave into the northern High Plains early on June 28. An increasing low level jet of 45 to 60 knots developed through the Central Plains with a terminus over southeast South Dakota. The source airmass exhibited up to 3000-4000 J/kg elevated CAPE, significant DCAPE, and 40 to 50 knots of deep-layer effective shear. Storms intensified and organized into short bowing segments with swaths of damaging winds across southeast South Dakota and southwest Minnesota. On the more exposed southern periphery of convection, briefly stronger updrafts brought areas of hail as large as ping-pong balls across northwest Iowa.