Heavy Rains and Severe Storms: August 12-13, 2010

The stormy summer of '10 continues. This time thunderstorms developed in three waves. The first wave was during the evening of August 12 and moved into the northwestern Twin Cities at dusk. In the early morning hours of August 13, the second wave of storms developed and moved across the Twin Cities, producing some spectacular lightning displays. Hardest hit by the heavy rain in this latest round of storms was in a 30 mile band from southern Kandiyohi County east southeastward through the western and southern suburbs of the Twin Cities and then to Wabasha County. The highest 24 hour precipitation total reported so far is 4.16 at Wabasha in Wabasha County. 4.05 inches was reported at Zumbrota in Goodhue County. Another swath of heavy rain fell in Pope and western Stearns County. Street flooding was reported during the storm at Cologne, Chaska and Carver in Carver County. A foot of water covered Highway 7 in Minnetonka during the storm.

There was also severe weather with these storms too, besides the heavy rains. At least one tornado was reported in Lac Qui Parle County with "debris in the air" reported 1 mile N of Louisberg at 6:22pm, August 12. Strong winds also caused damage to homes in Dakota County near Farmington and Lakeville and also in Northern Chisago County.

The third wave of thunderstorms developed in the afternoon and evening of August 13 and produced some brief tornado touchdowns during the evening in Dodge and Olmstead Counties. There was intense rainfall with the third wave too with water up to car doors at Apache Mall in Rochester, and street flooding was reported.

Radar-based precipitation estimate

National Weather Service Storm Summaries