Hail in Lac Qui Parle County, Minnesota

Mostly nickel sized hail but a few quarters also reported.

A mid-level wave embedded in the eastern periphery of a developing ridge produced two periods of severe thunderstorms across much of west-central and central MN on Sunday, July 27th. Westerly flow advected in an extremely unstable airmass with favorable amounts of wind shear to support rotating updrafts. Late morning convection occurred across western MN producing quarter size hail and damaging wind gusts across Lac qui Parle and Chippewa Counties.

The second round of thunderstorms developed over western MN and grew into multi-cellular clusters becoming more widespread through the course of the afternoon. These storms also produced torrential rainfall over a short period of time, leading to several roadways being flooded or washed out in Stevens Co near Chokio and Alberta. There was also urban flooding along Hwy 36 and residential areas in Roseville in Ramsey Co. Rainfall rates in these areas exceeded 3 to 4 inches per hour.

Mainly quarter to half-dollar size hail was reported across western MN. The largest hail reports were focused near the Twin Cities metro with quarter size to golf ball size reported by trained spotters. The golf ball size hail fell in Plymouth (Hennepin Co) and one mile southeast of Falcon Heights (Ramsey). As for damaging winds, most severe wind reports measured between 60 to 70 mph. The strongest estimated wind gusts were about 64 knots or 74 mph, which buckled grain bins near Sanburg (Kandiyohi Co) and damaged power poles.