Thunderstorm Wind in Nobles County, Minnesota

Several power poles were snapped by strong thunderstorm winds, which downed powerlines across Interstate 90. A car stopped on the roadway to avoid crossing downed powerlines, and was struck from behind by a tractor trailer, resulting in the (indirect) fatality of one vehicle passenger and injury of the other three passengers in the car as well as one from another car.

A cluster of early morning storms developed on the nose of steeper mid-level lapse rates and marginally strong elevated wind shear across far southeast South Dakota. Multicell convection produced spotty large hail moving into southwest Minnesota. During the afternoon, convection re-ignited near an advancing mesoscale convective vortex and moved northeast from eastern Nebraska into southwest Minnesota. With greater surface-based instability with a MLCAPE of 2000-3000 J/kg and deep-layer shear of 40-50 knots, storms quickly organized into a QLCS structure and produced hail up to ping-pong ball size, wind to 90 mph, and a few tornadoes across southwest Minnesota. Presidential Disaster Declarations were granted to Cottonwood and Nobles Counties for damages to public infrastructure.