Flood — Winona, Minnesota

2010-09-23 to 2010-09-24 · near Troy, Winona, Minnesota

Event narrative

Flooding occurred along rivers, creeks, and streams as well as in low-lying areas, with the worst impacts seen in the northern parts of the county. Numerous roads were closed and some were damaged by flood waters. A portion of County Road 74 southwest of Elba was closed due to high water. The Whitewater River saw major flooding, which did some damage to portions of the Whitewater State Park, which was evacuated. Five homes incurred minor damage. At mid-morning on the 23rd, the majority of the rain had fallen with 5.52 inches measured at a location 5 miles north of St. Charles and 4.20 inches in Winona.

Wider weather episode

A stationary front set up across southern Minnesota on the evening of September 22nd. As an unusually moist air mass flowed over this boundary, heavy rain developed and fell repeatedly across the area during the evening and overnight hours. Soils were abnormally wet for this time of year, therefore the extreme rainfall amounts that fell caused widespread significant river flooding and flash flooding. Infrastructure was greatly affected with millions of dollars of damage, while private properties were also heavily damaged. Dodge, Olmsted, Wabasha, Winona, and Mower counties were included in federal disaster declarations (FEMA-1941-DR).

View location on OpenStreetMap → (43.8463, -92.0792)

Source: NOAA Storm Events Database, event_id 259913. Narrative written by the NWS forecast office that issued the report.