Name: Hail in Iowa, July 21, 2009
Start: 2009-07-21T16:57
End: 2009-07-21T21:26
Location: Iowa

Where it happened

Every event with a place to put it. 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: $2,000
Crop damage: $15,000
Events: 2

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 DMX wrote it up.

A low pressure system passed south of Iowa during the day as an inverted trough and weak upper level system passed over the state during the afternoon and evening. Skies had cleared during the day, allowing for some instability to develop. By late afternoon, most unstable CAPE values were between 1000 and 2000 J/kg and the lifted indices fell to between -3 and -6 C. Shear was relatively weak with only 20 to 30 kts available. Downdraft CAPE was between 500 and 800 J/kg, with 300 to 400 J/kg of CAPE available in the -10 to -30 C layer of the atmosphere. Thunderstorms developed over northern Iowa during the late afternoon and evening hours and moved southeast into the central sections before dissipating. One of the thunderstorms produced penny size hail as it moved through Webster County, another produced quarter size hail as it moved through Worth County.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Des Moines, IA wrote its last area forecast discussion before the first event at Jul 21, 1:52 PM CST, 3 hours 5 minutes earlier.

Area forecast discussion, Jul 21, 1:52 PM CST, 3 hours 5 minutes before

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Hazardous weather outlook, Jul 21, 3:48 AM CST, 13 hours 9 minutes before

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In the hours before

Special weather statement, Jul 21, 4:52 PM CST, 5 minutes before

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The radar

The Des Moines radar (KDMX), 116 km away, was scanning. The volume nearest the first event began at 22:57 UTC.

Open the radar archive at this moment

Event by event

2 hail. Local standard time, as filed.

Hail, Webster

When: July 21, 4:57 PM CST
Where: Webster County, 5.34 mi NW of Clare
Measured: 0.75 in hail
Crop damage: $5,000
Reported by: Public
Coordinates: 42.630, -94.430

Public reported event which was relayed from NSSL.

Hail, Worth

When: July 21, 9:26 PM CST
Where: Worth County, 5.07 mi W of Kensett
Measured: 1 in hail
Property damage: $2,000
Crop damage: $10,000
Reported by: Trained Spotter
Coordinates: 43.340, -93.320

What these are

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

More

Every storm in Iowa in 2009 Every state in 2009 This day in weather history Warnings in Iowa, July 2009

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: 173496, 173497.