Hail and Damaging Winds in Iowa, July 17 to 18, 2001

Name: Hail and Damaging Winds in Iowa, July 17 to 18, 2001
Start: 2001-07-17T23:32
End: 2001-07-18T01:00
Location: Iowa

July 17 to 18, 2001 · NWS DMX · 3 events in 3 counties and zones

A very unstable airmass was in place over Iowa during the evening of the 17th. A warm front lifted north into the state.

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

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $18,000
Crop damage: $12,000
Events: 3

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 very unstable airmass was in place over Iowa during the evening of the 17th. A warm front lifted north into the state. Behind it were dew point temperatures in the upper 70s to mid 80s F. Surface temperatures soared to over 100 degrees over the far southwest corner of the state. Lifted indices were lower than -14 C. with CAPE values measured with the 00 UTC sounding data from Omaha at near 8200 J/kg. Although the freezing level was nearly 16,000 feet, intense storms were able to produce severe hail. Intense thunderstorms developed over east central Nebraska during the mid evening hours. The storms moved east into western Iowa and produced hail and high winds. One inch diameter hail fell on the town of Nodaway in Adams County. The storms continued east, but hail production diminished as they did. The storms became high wind producers as the continued east. Gusts of 60 to 65 MPH swept through Taylor and Ringgold Counties. Both of the counties reported widespread power outages and tree damage. After moving through the Mt Ayr area, the storm weakened and then drifted southeast out of the state.

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 17, 2:33 PM CST, 8 hours 59 minutes earlier.

Area forecast discussion, Jul 17, 2:33 PM CST, 8 hours 59 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
333 PM CDT TUE JUL 17 2001

PRIMARY CONCERNS ARE CONVECTION OVERNIGHT AND WEDNESDAY MORNING.
THERE ARE AMPLE BOUNDARIES OVER THE STATE BUT THE BEST INSTABILITY
AND MOISTURE CONVERGENCE ARE OVER NEBRASKA WHERE 20-30KT LOW LEVEL
FLOW IS BRINGING IN LOTS OF MOISTURE TO INTERSECT WITH A WARM
FRONTAL BOUNDARY.  XPCT CONVECTION TO OCCUR IN THAT AREA THIS
EVENING AND SPREAD INTO OUR CWA LATE THIS EVE AND OVERNIGHT.  HE
MAIN THREAT SHOULD BE HEAVY RAIN AND GUSTY WIND BUT ISOLATED LARGE
HAIL IS POSSIBLE.  THE MODELS DO BUILD THE SCEN U.S. RIDGE NORTH
WITH TIME BUT THROUGH AT LEAST EARLY THURSDAY A SERIES OF SHORTWAVES
WILL RIDE OVER THE RDGE AND AFFECT CENTRAL IOWA'S WEATHER WITH
SCATTERED THUNDERSTORMS.  TIMING WILL BE DIFFICULT AS THERE WILL BE
A NUMBER OF BOUDARIES AROUND...WINDS WILL BE LIGHT BUT JUST AS IN
THE CASE OF THIS MORNING THAT MAY BE ENOUGH FOR INITAIL
DEVELOPMENT...AND WE WILL BE DEALING WITH REMNANTS OF ANY MCS THAT
DEVELOPS OUT WEST.  FOR THESE REASONS I DECIDED NOT TO TRY AND PLACE
TOO DETAILED OF A TIMING ELEMENT IN THE ZONES.

DWPNTS IN THE 70S AND 80S AND FORECAST LOWS IN THE MID 70S WITH
HIGHS IN THE 90S WARRANT THE HEAT ADVISORY TO BE CONTINUED THROUGH
AT LEAST WEDNESDAY.

.DSM...HEAT ADVISORY TONIGHT AND WEDNESDAY
IAZ004>005-015-023>025-033>036-044>049-057>062-070>075-081>086-092>097.

FAB

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

2 thunderstorm wind, 1 hail. Local standard time, as filed.

Hail, Adams

When: July 17, 11:32 PM CST
Where: Adams County, Nodaway
Measured: 1 in hail
Property damage: $3,000
Crop damage: $10,000
Reported by: LAW ENFORCEMENT
Coordinates: 40.933, -94.883

Thunderstorm Wind, Taylor

When: July 18, 12:40 AM CST
Where: Taylor County, Bedford
Measured: 52 kt (60 mph)
Property damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 40.667, -94.717

Thunderstorm Wind, Ringgold

When: July 18, 1:00 AM CST
Where: Ringgold County, Mt Ayr
Measured: 56 kt (64 mph)
Property damage: $10,000
Crop damage: $2,000
Reported by: TRAINED SPOTTER
Coordinates: 40.717, -94.233

What these are

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

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

The same day elsewhere

Every storm in Iowa in 2001 Every state in 2001 This day in weather history Warnings in Iowa, July 2001

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: 5252282, 5252283, 5252284.