Flash Flood and Damaging Winds in Wisconsin, July 25, 1999

Name: Flash Flood and Damaging Winds in Wisconsin, July 25, 1999
Start: 1999-07-25T18:32
End: 1999-07-25T20:30
Location: Wisconsin

July 25, 1999 · NWS MKX · 4 events in 2 counties and zones

) and proceeded to move southeast at about 15 mph. The storms produced wet microbursts that levelled trees and stop signs on the southside of Madison.

Where it happened

Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $32,000
Crop damage: None recorded
Events: 4

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS MKX wrote it up.

An isolated cluster of severe thunderstorms developed north of the Madison area (Dane Co.) and proceeded to move southeast at about 15 mph. The storms produced wet microbursts that levelled trees and stop signs on the southside of Madison. Two vehicles were damaged by tree branch debris. It was the same story in Rock County where trees were toppled by powerful winds in Edgerton and south of Clinton. The slow moving thunderstorms also dumped torrential rains at the rate of 1 to 2 inches per hour. The net result was a brief flash flood on the southside of Madison. Several roads were closed due to water levels of 3 to 5 feet. Some erosion of roadside banks was noted and several cars stalled in the deep water. Unofficial rainfall observations indicate that 4 inches of rain fell in less than 2 hours from Madison to Stoughton (Dane Co.).

The radar

The Milwaukee radar (KMKX), 72 km away, was scanning. The volume nearest the first event began at 00:32 UTC.

Open the radar archive at this moment

Event by event

3 thunderstorm wind, 1 flash flood. Local standard time, as filed.

Thunderstorm Wind, Dane

When: July 25, 6:32 PM CST
Where: Dane County, Madison
Property damage: $15,000
Reported by: NEWSPAPER
Coordinates: 43.070, -89.420

Thunderstorm Wind, Rock

When: July 25, 6:45 PM CST to 7:45 PM CST
Where: Rock County, Edgerton
Property damage: $1,000
Reported by: LAW ENFORCEMENT
Coordinates: 42.830, -89.070

Flash Flood, Dane

When: July 25, 6:45 PM CST to 8:30 PM CST
Where: Dane County, Madison
Property damage: $15,000
Reported by: LAW ENFORCEMENT
Coordinates: 43.067, -89.418 (the zone’s center; the record gives no point)

Thunderstorm Wind, Rock

When: July 25, 7:10 PM CST
Where: Rock County, 4 mi S of Clinton
Property damage: $1,000
Reported by: LAW ENFORCEMENT
Coordinates: 42.520, -88.870

What these are

Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Wisconsin in 1999 Every state in 1999 This day in weather history Warnings in Wisconsin, July 1999

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-30. Each event’s entry at NCEI: 5710850, 5710851, 5710853, 5710852.