June 28-29, 2020 Flash Flooding
Heavy Rains Bring Flooding To Western Wisconsin
Introduction
A slow moving, and at times stationary, warm front lifted across eastern Minnesota and western Wisconsin late on the evening of June 28th into the early morning hours of June 29th, as a complex of showers and thunderstorms rotated across central Minnesota. This slow moving front was accompanied by a strong nocturnal low-level jet, which focused an area of extremely unstable conditions and a very moist airmass into this area.
Extensive flooding developed across western parts of Wisconsin in St. Croix, Dunn, and Pierce counties. Numerous roads were washed out, with many others becoming impassable due the rising flood waters. At least a dozen water rescues took place in and near the town of Baldwin, where people became stranded in their vehicles and homes. On social media, locals noted they hadn't seen flooding like this in years. Drone footage, shown below, from the St. Croix County Sheriff's Office shows the extent of the flood damage.
Heavy Rain & Flash Flood Warnings
As heavy rain continued to train across western Wisconsin, flash flood warnings were issued for portions of Dunn, Barron, Pierce, St. Croix counties in western Wisconsin during the early morning hours on June 29, 2020. Extremely heavy rainfall caused extensive flooding in St. Croix, Dunn, and Pierce Counties. Numerous roads were washed out. At least a dozen water rescues took place from homes and cars in and near Baldwin. Unfortunately, one fatality occurred when a man drove into flood waters.
Rainfall totals after the event ended show an arch of heavy rain stretching from western and southern Minnesota into western Wisconsin. The highest rainfall totals were observed between the Twin Cities and Eau Claire, were locally 8+ inches of rain fell over a short period of time.
River Observations
The Chippewa, St. Croix, and the Upper Mississippi-Black-Root Watersheds were hard hit during the June 27-29 event. This caused local rivers, streams, and creeks to experience rapid rises in water.
While it took awhile for flood waters to drain into the Mississippi River, observations at the river gauge in Prescott, Wisconsin did show a few rises as the flood waters reached the Mississippi River.
