Heavy Rain, Potential Flooding Today

The risk for flash flooding and river rises continues for much of the day south of Interstate 90 with renewed storm development expected in the early afternoon, which could result in another 2 to 4 inches of rain falling over NE Iowa and SW Wisconsin. Read More >

Overview

Thunderstorms developed across mainly western and central Wisconsin on Wednesday, August 11th, 2021. Some storms were severe, most notably in Monroe County, WI where two tornadoes and 1" hail occurred. One tornado (EF1) destroyed a barn and snapped stands of hardwood trees in the area. A second tornado (EF0) formed before the 1st one dissipated and damaged trees and crops slightly northeast of the original one. Damage from both tornadoes was sporadic. Terrain in the area made it a challenge to survey a consistent path. Overall, the worst damage, rated EF1, was found near the initial touchdown site.

Tornadoes
Photos

Tornadoes:

Tornado - Norwalk, WI
MONROE COUNTY

Date	August, 11 2021
Time (Local)	1:45-1:59 pm
EF Rating	EF1
Est. Peak Winds	105 mph
Path Length	6 miles
Max Width	80 yards
Injuries/Deaths	0 / 0
Summary: A tornado caused sporadic damage across parts of rural Monroe County. Hardest hit was a barn just north of Norwalk but most of the damage involved sheared trees and crops. Path was intermittent towards the end of the track.

Track Map

Downloadable KMZ File

Tornado - Wilton / Clifton, WI
MONROE COUNTY

Date	August, 11 2021
Time (Local)	1:55-2:02 pm
EF Rating	EF1
Est. Peak Winds	90 mph
Path Length	3 miles
Max Width	75 yards
Injuries/Deaths	0 / 0
Summary: A second tornado had intermittent touchdowns in rural Monroe County, mainly damaging tree stands and crops.

Track Map

Downloadable KMZ File

The Enhanced Fujita (EF) Scale classifies tornadoes into the following categories:

EF0 Weak 65-85 mph	EF1 Moderate 86-110 mph	EF2 Significant 111-135 mph	EF3 Severe 136-165 mph	EF4 Extreme 166-200 mph	EF5 Catastrophic 200+ mph

Photos:

NWS damage survey from Norwalk, WI area:


Tornado Damage Northwest of Norwalk, WI (NWS Survey)	Tornado Damage Northwest of Norwalk, WI (NWS Survey)	Tornado Damage Northwest of Norwalk, WI (NWS Survey)	Tornado Damage Northwest of Norwalk, WI (NWS Survey)