Hail and Damaging Winds in Iowa, July 12, 1994

Name: Hail and Damaging Winds in Iowa, July 12, 1994
Start: 1994-07-12T12:40
End: 1994-07-12T17:30
Location: Iowa

July 12, 1994 · 5 events in 4 counties and zones

3 hail, 2 thunderstorm wind, as filed by the National Weather Service.

Where it happened

Every event with a place to put it; 5 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

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The toll

Deaths: 0
Injuries: 0
Property damage: $115,000
Crop damage: $151,000
Events: 5

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.

Event by event

3 hail, 2 thunderstorm wind. Local standard time, as filed.

Thunderstorm Wind, Clayton

When: July 12, 12:40 PM CST
Where: Clayton County, Strawberry Point
Measured: 50 kt (58 mph)
Property damage: $50,000
Crop damage: $500
Coordinates: 43.083, -95.151 (the zone’s center; the record gives no point)

Thunderstorm Wind, Dubuque

When: July 12, 1:37 PM CST
Where: Dubuque County, Dubuque
Measured: 61 kt (70 mph)
Property damage: $50,000
Crop damage: $50
Coordinates: 42.469, -90.882 (the zone’s center; the record gives no point)

Hail, Guthrie

When: July 12, 3:35 PM CST
Where: Guthrie County, Guthrie to Center
Measured: 0.75 in hail
Property damage: $5,000
Crop damage: $50,000
Coordinates: 41.684, -94.501 (the zone’s center; the record gives no point)

Hail, Guthrie

When: July 12, 3:50 PM CST
Where: Guthrie County, Bayard
Measured: 0.75 in hail
Property damage: $5,000
Crop damage: $50,000
Coordinates: 41.684, -94.501 (the zone’s center; the record gives no point)

Hail, Mills

When: July 12, 5:30 PM CST
Where: Mills County, Pacific Junction
Measured: 1 in hail
Property damage: $5,000
Crop damage: $50,000
Coordinates: 41.034, -95.621 (the zone’s center; the record gives no point)

A thunderstorm complex drifted over northwest and north central Iowa during the previous night. This complex formed on the cold side of a decaying cold front that was moving southeast across the central U.S. The front became stationary east to west across Iowa, aligned with the outflow boundary from the complex. During the afternoon the airmass became very unstable. Surface based lifted indices reach -12 with convective available potential energy values in the 1000 to 2000 J-Kg-1 range. Thunderstorms erupted along the boundary. Though most of them remained below severe limits, a few did produce severe weather. High winds blew down trees and damaged a truck in Strawberry Point of Clayton County. As the storms moved through Dubuque County, high winds broke at least 2 windows in one home, and tore shingles off the roof of another. The line of storm developed southwest from those in northeast Iowa into the west central counties of the state. From there, the line moved east and south. Little in the way of severe weather was reported following the reports over northeast Iowa, though three quarter inch diameter hail did fall northwest of Guthrie Center, in Guthrie County. Later, one cell dropped hail nearly an inch in diameter in Mills County at Pacific Junction. The main event with these storms was the torrential rainfall. Many areas received 1 to 2 inches of rain in under an hour. Flash flooding became a problem in the Dallas and Madison County area. WSR-88D radar precipitation estimates showed 2 1/2 to 3 1/2 inches of rain in many area of southern Dallas County into Madison County. One spot indication from radar showed rainfall in excess of 3 1/2 inches. Ground truth revealed that 4 inches of rain had fallen in 90 minutes in the town of Earlham, in Madison County. Most of the rain that fell did so in less than 2 hours. There were several reports of water overtopping roads from Madison County and the southern part of Dallas County. The storms progressed east into Polk and Warren Counties. Heavy rainfall occurred, but only briefly. Reports of 1 to 1 1/2 inches of rain in under an hour were received. This did cause some minor street flooding in the Des Moines metropolitan area, but no other significant flooding was reported.

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.
Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.

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

The same day elsewhere

Every storm in Iowa in 1994 Every state in 1994 This day in weather history Warnings in Iowa, July 1994

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 2026-09-24. Each event’s entry at NCEI: 10321546, 10321724, 10321735, 10321736, 10323788.