Tornadoes and Flash Flooding in Iowa, May 24 to 25, 2004

Name: Tornadoes and Flash Flooding in Iowa, May 24 to 25, 2004
Start: 2004-05-24T13:23
End: 2004-05-25T00:45
Location: Iowa

May 24 to 25, 2004 · NWS DMX · 119 events in 38 counties and zones

Once again it was a very active severe weather day over Iowa. The frontal system that had moved through the state on the night of the 22nd was returning north as a warm front.

Where it happened

Every event with a place to put it; 35 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: 1
Property damage: $2.6 million
Crop damage: $593,000
Events: 119

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.

Once again it was a very active severe weather day over Iowa. The frontal system that had moved through the state on the night of the 22nd was returning north as a warm front. This time Iowa did not get completely into the warm sector. The surface front was dragged north into Iowa by low pressure that moved out of Kansas northeast into central Iowa by the mid to late evening. The airmass was pushed southeast out of the state by a cold front that passed through the state during the evening and early morning hours. The airmass in the warm sector became very unstable. Lifted indices were around -13 C with CAPE values greater than 5000 J/kg by the late afternoon. The air advected north into Iowa during the day and into the evening. Thunderstorms erupted in two places. The first to affect the DSM CWA was the development of several elevated supercells over west central into southwest Iowa. The storms continued to lift east and northeast across the area. A few tornadoes touched down, however with the very elevated nature of the storms it was very difficult for the tornadoes to reach the ground. By the late afternoon, a solid squall line developed along the cold front. The line took on a Line Echo Wave Pattern by evening. Several segments of the line bowed out, resulting in high winds. At times the winds reached 80 MPH. One of the thunderstorms produced high winds in the Early area of Sac County. They overturned a semi-tractortrailer truck, causing $80,000 damage and causing minor injuries to the driver. Tornadoes that formed along this line actually formed where the Rear Flank Downdraft cut through the line. A clear meso was formed and the small tornadoes advanced around the meso and were in front of the thunderstorm line. Touchdowns were all brief. Hail was common with the stronger storm, with much of it in the one to one and three-quarter inch in diameter. Given the antecedent soil conditions in Iowa, flash flooding became a major issue. Numerous counties reported flash flooding as rainfall of one to 4 inches in spots resulted in flooded highways. The thunderstorms formed into an MCC by the early evening hours. As they moved out of the state, they delivered one more punch to the state. High winds developed in the wake of the complex. Several counties of north central, northeast, and central Iowa received high winds. Damage occurred in several locations to both trees and out buildings. Sustained winds across the area were in the 25 to 45 MPH range with some higher gusts. Clarion reported a wind gust of 63 MPH for the highest wind gust reported.

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 May 24, 4:45 AM CST, 8 hours 38 minutes earlier.

Area forecast discussion, May 24, 4:45 AM CST, 8 hours 38 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
545 AM CDT MON MAY 24 2004

.DISCUSSION...
TRICKY FORECAST WITH MAIN FOCUS ON THE SIGNIFICANT SEVERE EVENT THIS
AFTERNOON AND EVENING. THE CWA IS HIGHLIGHTED IN SLT-MOD-HIGH RISK
FROM NORTH TO SOUTH FOR TODAY. PER COORDINATION WITH SPC...THE MOD
AND HIGH RISK AREAS ACROSS IOWA WILL BE SHIFTED SOUTHWARD WITH THE
NEW DAY 1 OUTLOOK AT 8 AM. SPC HAS ALSO ISSUED A PUBLIC SEVERE
WEATHER OUTLOOK. THE 00Z MODEL RUNS HAD A MORE NORTHERLY FRONTAL
PLACEMENT NEAR THE IA/MO BORDER...WITH HIGHER CAPE AND MORE
FAVORABLE SHEAR NOSING INTO THE STATE. HOWEVER...06Z ETA HAS
SUPPRESSED THE FRONT FARTHER SOUTH...ALONG WITH THE BEST
INSTABILITY. THUS BELIEVE THE POTENTIAL FOR STRONG TORNADOES HAS
DIMINISHED IN THE SOUTH. HOWEVER...SHEAR PROFILES ARE VERY FAVORABLE
AND SHOULD SUPPORT INITIAL SUPERCELLS WITH A FEW TORNADOES
POSSIBLE...MAINLY IN FAR SOUTHWEST COUNTIES.  CONVECTIVE INITIATION
TIME LOOKS TO BE EARLY AFTERNOON IN SE NEBRASKA...WITH STORMS MOVING
EASTWARD ACROSS CWA FROM MID AFTERNOON THROUGH THE EVENING HOURS.
BOWING LINE STRUCTURE EXPECTED TO PRODUCE VERY STRONG STRAIGHT LINE
WINDS AND VERY LARGE HAIL ACROSS THE SOUTH...WITH MORE ISOLD SEVERE
THREAT NORTH OF HIGHWAY 30. FLASH FLOOD GUIDANCE VALUES ARE QUITE
LOW ACROSS MOST OF CENTRAL IOWA FROM RECENT RAINS AND WILL CONTINUE
FLOOD WATCH THIS AFTERNOON THROUGH THE OVERNIGHT FOR ENTIRE CWA.
SOUTH HALF MORE FAVORED FOR 1-2 INCH RAINS AND ISOLD HIGHER...WITH
SOME ISOLD FLASH FLOODING. LESSER RAINS EXPECTED NORTH...BUT ANY
RAIN WILL AGGRAVATE ONGOING HYDRO SITUATION. LOOKING AHEAD TO
TUESDAY...FRONT STALLS IN MISSOURI AND HAVE BOOSTED POPS IN THE
SOUTH. MODELS SUGGESTING SOME RAIN POSSIBLE WED NITE OR THURS TIME
FRAME IN THE NORTHEAST...BUT WILL LET DAY SHIFT RE-EVALUATE.
STRONGER SYSTEM STILL ON TARGET FOR FRIDAY.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...FLOOD WATCH ENTIRE CWA FROM NOON
TODAY UNTIL 4 AM TUESDAY.

&&

KINNEY

Hazardous weather outlook, May 24, 6:01 AM CST, 7 hours 22 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
701 AM CDT MON MAY 24 2004

...SEVERE WEATHER OUTBREAK EXPECTED ACROSS SOUTHERN IOWA THIS
AFTERNOON AND EVENING...

IAZ081>086-092>097-251100-
ADAMS-APPANOOSE-CLARKE-DAVIS-DECATUR-LUCAS-MONROE-RINGGOLD-TAYLOR-
UNION-WAPELLO-WAYNE-
701 AM CDT MON MAY 24 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHERN IOWA...SOUTH OF
HIGHWAY 34.

.DAY ONE...TODAY AND TONIGHT

THERE IS A HIGH RISK OF SEVERE WEATHER ACROSS SOUTHERN IOWA FROM
MID AFTERNOON THROUGH THE EVENING HOURS. STRONG WIND SHEAR AND
INSTABILITY WILL SUPPORT SUPERCELL THUNDERSTORMS DURING THE
AFTERNOON AND EARLY EVENING...WITH VERY LARGE HAIL AND DAMAGING
STRAIGHT LINE WINDS. TORNADOES ARE ALSO POSSIBLE DURING THIS
TIME FRAME...A FEW POTENTIALLY STRONG. THE MAIN AREA FOR THESE
THREATS FROM MID AFTERNOON INTO THE EARLY EVENING IS ALONG AND
SOUTHWEST OF A LINE FROM CORNING TO CRESTON TO MOUNT AYR. THEN
DURING THE EVENING HOURS...A THUNDERSTORM COMPLEX IS EXPECTED
TO EVOLVE AND RACE EASTWARD ACROSS SOUTHERN IOWA...WITH THE MAIN
THREAT OF VERY STRONG DAMAGING STRAIGHT LINE WINDS. SOME LOCATIONS
WILL RECEIVE 1 TO 2 INCHES OF RAINFALL...WITH ISOLATED 3 INCH
AMOUNTS. ISOLATED FLASH FLOODING IS POSSIBLE TONIGHT GIVEN THE
SATURATED SOIL CONDITIONS. HEAVY RAINS WILL ALSO AGGRAVATE THE
ONGOING RIVER AND STREAM FLOODING SITUATION.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THUNDERSTORMS ARE EXPECTED AT VARIOUS TIMES FROM FRIDAY INTO THE
WEEKEND. SEVERE WEATHER IS POSSIBLE...BUT IT IS TOO EARLY TO
DETERMINE SPECIFIC LOCATIONS...THREATS...AND TIMING.

.SPOTTER ACTIVATION STATEMENT...

SPOTTER ACTIVATION WILL BE NEEDED THIS AFTERNOON AND TONIGHT.

IAZ044>050-057>062-070>075-251100-
ADAIR-AUDUBON-BOONE-CARROLL-CASS-CRAWFORD-DALLAS-GREENE-GUTHRIE-
JASPER-MADISON-MAHASKA-MARION-MARSHALL-POLK-POWESHIEK-STORY-TAMA-
WARREN-
701 AM CDT MON MAY 24 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL IOWA...BETWEEN THE
HIGHWAY 30 AND HIGHWAY 34 CORRIDORS.

.DAY ONE...TODAY AND TONIGHT

THERE IS A MODERATE RISK OF SEVERE WEATHER ACROSS CENTRAL IOWA FROM
MID AFTERNOON THROUGH THE EVENING HOURS. WIND SHEAR AND INSTABILITY
WILL SUPPORT SOME SUPERCELL THUNDERSTORMS INITIALLY...WITH LARGE
HAIL...DAMAGING WINDS...AND ISOLATED TORNADOES POSSIBLE. THE MAIN
AREA FOR THESE THREATS WILL BE LOCATIONS FROM CARROLL AND DENISON...
SOUTH TO ATLANTIC. THEN DURING THE EVENING...A THUNDERSTORM COMPLEX
IS EXPECTED TO RACE EASTWARD ACROSS THE AREA...WITH THE MAIN THREAT
OF VERY STRONG DAMAGING STRAIGHT LINE WINDS. SOME LOCATIONS WILL
RECEIVE 1 TO 2 INCHES OF RAINFALL...WITH ISOLATED 3 INCH AMOUNTS.
ISOLATED FLASH FLOODING IS POSSIBLE TONIGHT GIVEN THE SATURATED SOIL
CONDITIONS. HEAVY RAINS WILL ALSO AGGRAVATE THE ONGOING RIVER AND
STREAM FLOODING SITUATION.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THUNDERSTORMS ARE EXPECTED AT VARIOUS TIMES FROM FRIDAY INTO THE
WEEKEND. SEVERE WEATHER IS POSSIBLE...BUT IT IS TOO EARLY TO
DETERMINE SPECIFIC LOCATIONS...THREATS...AND TIMING.

.SPOTTER ACTIVATION STATEMENT...

SPOTTER ACTIVATION WILL BE NEEDED THIS AFTERNOON AND TONIGHT.

IAZ004>007-015>017-023>028-033>039-251100-
BLACK HAWK-BREMER-BUTLER-CALHOUN-CERRO GORDO-EMMET-FRANKLIN-GRUNDY-
HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-PALO ALTO-POCAHONTAS-SAC-
WEBSTER-WINNEBAGO-WORTH-WRIGHT-
701 AM CDT MON MAY 24 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHERN IOWA...NORTH OF
HIGHWAY 30.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS ARE EXPECTED TO MOVE INTO NORTHWEST IOWA DURING
THE EARLY AFTERNOON...THEN MOVE EAST ACROSS NORTHERN IOWA
DURING THE LATE AFTERNOON AND EVENING HOURS. ISOLATED SEVERE
THUNDERSTORMS ARE POSSIBLE...WITH THE THREATS BEING LARGE HAIL AND
ISOLATED DAMAGING STRAIGHT LINE WIND GUSTS. SOME THUNDERSTORMS WILL
PRODUCE RAINFALL AMOUNTS OF ONE HALF TO ONE INCH...WHICH COULD
AGGRAVATE THE ONGOING FLOOD SITUATION ON MANY RIVERS AND STREAMS IN
NORTHERN IOWA.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THUNDERSTORMS ARE EXPECTED AT VARIOUS TIMES FROM FRIDAY INTO THE
WEEKEND. SEVERE WEATHER IS POSSIBLE...BUT IT IS TOO EARLY TO
DETERMINE SPECIFIC LOCATIONS...THREATS...AND TIMING.

.SPOTTER ACTIVATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND TONIGHT.

KINNEY

The radar

The Des Moines radar (KDMX), 17 km away, was scanning. The volume nearest the first event began at 19:24 UTC.

Open the radar archive at this moment

Event by event

47 hail, 33 thunderstorm wind, 22 flash flood, 13 high wind, 4 tornado. Local standard time, as filed.

Hail, Crawford

When: May 24, 1:23 PM CST
Where: Crawford County, 5 mi S of Kiron
Measured: 1.25 in hail
Property damage: $3,000
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.600, -93.617

Hail, Crawford

When: May 24, 1:33 PM CST
Where: Crawford County, 1 mi E of Kiron
Measured: 1.75 in hail
Property damage: $5,000
Crop damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 42.037, -95.382 (the zone’s center; the record gives no point)

Hail, Cass

When: May 24, 1:47 PM CST
Where: Cass County, Anita
Measured: 0.88 in hail
Property damage: $2,000
Crop damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 41.717, -93.633

Hail, Cass

When: May 24, 1:50 PM CST
Where: Cass County, Anita
Measured: 1.75 in hail
Property damage: $10,000
Crop damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 41.332, -94.928 (the zone’s center; the record gives no point)

Thunderstorm Wind, Sac

When: May 24, 2:00 PM CST
Where: Sac County, Early
Measured: 61 kt (70 mph) estimated gust
Injuries: 1 direct, 0 indirect
Property damage: $80,000
Reported by: NEWSPAPER
Coordinates: 41.500, -93.683

Hail, Guthrie

When: May 24, 2:10 PM CST
Where: Guthrie County, 2 mi NW of Casey
Measured: 0.75 in hail
Crop damage: $5,000
Reported by: GENERAL PUBLIC
Coordinates: 41.600, -93.617

Hail, Adair

When: May 24, 2:15 PM CST
Where: Adair County, 4 mi SE of Adair
Measured: 0.75 in hail
Crop damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 41.600, -93.717

Hail, Guthrie

When: May 24, 2:15 PM CST
Where: Guthrie County, 2 mi W of Menlo
Measured: 1 in hail
Property damage: $2,000
Crop damage: $5,000
Reported by: FIRE DEPT/RESCUE SQUAD
Coordinates: 41.684, -94.501 (the zone’s center; the record gives no point)

Hail, Guthrie

When: May 24, 2:22 PM CST
Where: Guthrie County, Menlo
Measured: 0.75 in hail
Crop damage: $2,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.684, -94.501 (the zone’s center; the record gives no point)

Hail, Pocahontas

When: May 24, 2:50 PM CST
Where: Pocahontas County, Palmer
Measured: 0.75 in hail
Crop damage: $5,000
Reported by: GENERAL PUBLIC
Coordinates: 41.583, -93.717

Hail, Humboldt

When: May 24, 3:01 PM CST
Where: Humboldt County, 1 mi W of Pioneer
Measured: 0.88 in hail
Property damage: $2,000
Crop damage: $5,000
Reported by: GENERAL PUBLIC
Coordinates: 41.483, -93.733

Hail, Pocahontas

When: May 24, 3:04 PM CST
Where: Pocahontas County, 6 mi SE of Palmer
Measured: 0.88 in hail
Property damage: $2,000
Crop damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 42.734, -94.679 (the zone’s center; the record gives no point)

Hail, Pocahontas

When: May 24, 3:05 PM CST
Where: Pocahontas County, 6 mi E of Palmer
Measured: 0.88 in hail
Property damage: $2,000
Crop damage: $5,000
Reported by: GENERAL PUBLIC
Coordinates: 41.583, -93.717

Hail, Webster

When: May 24, 3:06 PM CST
Where: Webster County, 2 mi SW of Clare
Measured: 0.88 in hail
Property damage: $2,000
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 42.428, -94.182 (the zone’s center; the record gives no point)

Tornado, Madison

When: May 24, 3:58 PM CST
Where: Madison County, 6 mi S of Earlham
Rating: F0
Path length: 0.5 mi
Path width: 50 yd
Crop damage: $2,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.331, -94.016 (the zone’s center; the record gives no point)

Tornado touched down briefly in farm fields south of Earlham.

Hail, Audubon

When: May 24, 4:09 PM CST
Where: Audubon County, 15 mi SSW of Audubon
Measured: 0.88 in hail
Property damage: $2,000
Crop damage: $5,000
Reported by: AMATEUR RADIO
Coordinates: 41.685, -94.906 (the zone’s center; the record gives no point)

Flash Flood, Dallas

When: May 24, 4:10 PM CST to 10:00 PM CST
Where: Dallas County, Countywide
Property damage: $100,000
Crop damage: $25,000
Reported by: TRAINED SPOTTER
Coordinates: 41.685, -94.040 (the zone’s center; the record gives no point)

Hail, Audubon

When: May 24, 4:15 PM CST
Where: Audubon County, Exira
Measured: 1 in hail
Property damage: $5,000
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.685, -94.906 (the zone’s center; the record gives no point)

Hail, Dallas

When: May 24, 4:22 PM CST
Where: Dallas County, 1 mi NW of De Soto
Measured: 1.75 in hail
Property damage: $5,000
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.685, -94.040 (the zone’s center; the record gives no point)

Flash Flood, Audubon

When: May 24, 4:25 PM CST to 10:15 PM CST
Where: Audubon County, Kimballton
Property damage: $25,000
Crop damage: $10,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.685, -94.906 (the zone’s center; the record gives no point)

Hail, Dallas

When: May 24, 4:26 PM CST
Where: Dallas County, 2 mi S of De Soto
Measured: 1 in hail
Property damage: $2,000
Crop damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 41.685, -94.040 (the zone’s center; the record gives no point)

Hail, Dallas

When: May 24, 4:32 PM CST
Where: Dallas County, 3 mi ESE of Van Meter
Measured: 1.75 in hail
Property damage: $10,000
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.685, -94.040 (the zone’s center; the record gives no point)

Hail, Madison

When: May 24, 4:34 PM CST
Where: Madison County, 10 mi NE of Winterset
Measured: 1 in hail
Property damage: $3,000
Crop damage: $5,000
Reported by: AMATEUR RADIO
Coordinates: 41.331, -94.016 (the zone’s center; the record gives no point)

Hail, Dallas

When: May 24, 4:35 PM CST
Where: Dallas County, 2 mi S of Waukee
Measured: 1 in hail
Property damage: $3,000
Crop damage: $5,000
Reported by: AMATEUR RADIO
Coordinates: 41.685, -94.040 (the zone’s center; the record gives no point)

Hail, Dallas

When: May 24, 4:38 PM CST
Where: Dallas County, 4 mi E of Van Meter
Measured: 1.75 in hail
Property damage: $15,000
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.767, -93.800

Hail covered Interstate 80.

Hail, Dallas

When: May 24, 4:39 PM CST
Where: Dallas County, 5 mi E of Van Meter
Measured: 1.75 in hail
Property damage: $15,000
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.685, -94.040 (the zone’s center; the record gives no point)

Hail, Dallas

When: May 24, 4:39 PM CST
Where: Dallas County, 2 mi E of Waukee
Measured: 0.88 in hail
Property damage: $2,000
Crop damage: $5,000
Reported by: AMATEUR RADIO
Coordinates: 41.767, -93.717

Tornado, Warren

When: May 24, 4:40 PM CST
Where: Warren County, 4 mi SW of Martensdale
Rating: F0
Path length: 0.2 mi
Path width: 30 yd
Crop damage: $1,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.767, -93.717

Tornado touched down briefly in a farm field along side of Interstate 35 at mile post 53.

Flash Flood, Carroll

When: May 24, 4:40 PM CST to 10:15 PM CST
Where: Carroll County, Countywide
Property damage: $75,000
Crop damage: $25,000
Reported by: LAW ENFORCEMENT
Coordinates: 40.733, -94.900

Hail, Polk

When: May 24, 4:42 PM CST
Where: Polk County, 2 mi SW of West Des Moines
Measured: 1.25 in hail
Property damage: $5,000
Crop damage: $2,000
Reported by: AMATEUR RADIO
Coordinates: 41.367, -93.817

Hail, Polk

When: May 24, 4:42 PM CST
Where: Polk County, 1 mi S of Grimes
Measured: 0.75 in hail
Crop damage: $3,000
Reported by: AMATEUR RADIO
Coordinates: 41.367, -93.817

Hail, Polk

When: May 24, 4:42 PM CST
Where: Polk County, West Des Moines
Measured: 1 in hail
Property damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 41.817, -93.700

Hail, Polk

When: May 24, 4:45 PM CST
Where: Polk County, West Des Moines
Measured: 1.5 in hail
Property damage: $10,000
Reported by: TRAINED SPOTTER
Coordinates: 40.667, -94.717

Hail, Polk

When: May 24, 4:48 PM CST
Where: Polk County, Des Moines
Measured: 1.75 in hail
Property damage: $25,000
Reported by: LAW ENFORCEMENT
Coordinates: 40.667, -94.717

Hail, Polk

When: May 24, 4:48 PM CST
Where: Polk County, West Des Moines
Measured: 1.5 in hail
Property damage: $10,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.686, -93.573 (the zone’s center; the record gives no point)

Hail, Warren

When: May 24, 4:50 PM CST
Where: Warren County, 1 mi S of Cumming
Measured: 0.75 in hail
Crop damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 40.700, -94.867

Hail, Polk

When: May 24, 4:50 PM CST
Where: Polk County, Des Moines
Measured: 0.88 in hail
Property damage: $3,000
Reported by: TRAINED SPOTTER
Coordinates: 40.700, -94.867

Hail, Polk

When: May 24, 4:52 PM CST
Where: Polk County, West Des Moines
Measured: 1.5 in hail
Property damage: $10,000
Reported by: AMATEUR RADIO
Coordinates: 40.650, -94.717

Hail, Polk

When: May 24, 4:54 PM CST
Where: Polk County, West Des Moines
Measured: 1 in hail
Property damage: $5,000
Reported by: AMATEUR RADIO
Coordinates: 41.483, -93.683

Hail, Warren

When: May 24, 4:56 PM CST
Where: Warren County, 3 mi W of Norwalk
Measured: 1.75 in hail
Property damage: $15,000
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.334, -93.561 (the zone’s center; the record gives no point)

Flash Flood, Guthrie

When: May 24, 4:58 PM CST to 10:15 PM CST
Where: Guthrie County, 3 mi E of Bagley
Property damage: $25,000
Crop damage: $10,000
Reported by: TRAINED SPOTTER
Coordinates: 41.400, -93.750

Hail, Warren

When: May 24, 5:00 PM CST
Where: Warren County, 1 mi N of Norwalk
Measured: 0.75 in hail
Crop damage: $3,000
Reported by: AMATEUR RADIO
Coordinates: 41.600, -93.617

Hail, Polk

When: May 24, 5:00 PM CST
Where: Polk County, Des Moines
Measured: 0.88 in hail
Property damage: $3,000
Reported by: AMATEUR RADIO
Coordinates: 40.750, -94.733

Hail, Polk

When: May 24, 5:02 PM CST
Where: Polk County, Des Moines
Measured: 0.88 in hail
Property damage: $3,000
Reported by: AMATEUR RADIO
Coordinates: 41.400, -93.817

Hail, Polk

When: May 24, 5:09 PM CST
Where: Polk County, Des Moines
Measured: 1 in hail
Property damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 41.883, -93.683

Flash Flood, Polk

When: May 24, 5:10 PM CST to 10:45 PM CST
Where: Polk County, West Des Moines
Property damage: $75,000
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.783, -93.617

Flash Flood, Humboldt

When: May 24, 5:15 PM CST to 8:00 PM CST
Where: Humboldt County, Countywide
Property damage: $100,000
Crop damage: $50,000
Reported by: EMERGENCY MANAGER
Coordinates: 41.667, -93.800

Flash Flood, Polk

When: May 24, 5:15 PM CST to 10:45 PM CST
Where: Polk County, Des Moines
Property damage: $100,000
Reported by: AMATEUR RADIO
Coordinates: 40.667, -94.717

Hail, Polk

When: May 24, 5:16 PM CST
Where: Polk County, 1 mi SW of Ankeny
Measured: 0.88 in hail
Property damage: $3,000
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 40.667, -94.717

Thunderstorm Wind, Polk

When: May 24, 5:30 PM CST
Where: Polk County, Windsor Hgts
Measured: 50 kt (58 mph) estimated gust
Property damage: $3,000
Reported by: TRAINED SPOTTER
Coordinates: 41.686, -93.573 (the zone’s center; the record gives no point)

Flash Flood, Boone

When: May 24, 5:30 PM CST to 10:30 PM CST
Where: Boone County, Countywide
Property damage: $100,000
Crop damage: $10,000
Reported by: TRAINED SPOTTER
Coordinates: 40.667, -94.417

High Wind, Butler

When: May 24, 5:30 PM CST to 10:30 PM CST
Where: Butler forecast zone
Measured: 40 kt (46 mph) measured sustained
Property damage: $25,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 40.650, -94.350

High Wind, Cerro Gordo

When: May 24, 5:30 PM CST to 10:30 PM CST
Where: Cerro Gordo forecast zone
Measured: 40 kt (46 mph) measured sustained
Property damage: $25,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 40.667, -94.233

High Wind, Franklin

When: May 24, 5:30 PM CST to 10:30 PM CST
Where: Franklin forecast zone
Measured: 40 kt (46 mph) measured sustained
Property damage: $25,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.733, -93.262 (the zone’s center; the record gives no point)

High Wind, Grundy

When: May 24, 5:30 PM CST to 10:30 PM CST
Where: Grundy forecast zone
Measured: 40 kt (46 mph) measured sustained
Property damage: $25,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 40.600, -94.383

High Wind, Hamilton

When: May 24, 5:30 PM CST to 10:30 PM CST
Where: Hamilton forecast zone
Measured: 40 kt (46 mph) measured sustained
Property damage: $25,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 40.667, -94.417

High Wind, Hancock

When: May 24, 5:30 PM CST to 10:30 PM CST
Where: Hancock forecast zone
Measured: 40 kt (46 mph) measured sustained
Property damage: $25,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 43.082, -93.734 (the zone’s center; the record gives no point)

High Wind, Hardin

When: May 24, 5:30 PM CST to 10:30 PM CST
Where: Hardin forecast zone
Measured: 52 kt (60 mph) measured gust
Property damage: $25,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 41.217, -93.233

High Wind, Marshall

When: May 24, 5:30 PM CST to 10:30 PM CST
Where: Marshall forecast zone
Measured: 40 kt (46 mph) measured sustained
Property damage: $25,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.036, -92.999 (the zone’s center; the record gives no point)

High Wind, Story

When: May 24, 5:30 PM CST to 10:30 PM CST
Where: Story forecast zone
Measured: 40 kt (46 mph) measured sustained
Property damage: $25,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 40.617, -93.917

High Wind, Tama

When: May 24, 5:30 PM CST to 10:30 PM CST
Where: Tama forecast zone
Measured: 40 kt (46 mph) measured sustained
Property damage: $25,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.080, -92.532 (the zone’s center; the record gives no point)

High Wind, Winnebago

When: May 24, 5:30 PM CST to 10:30 PM CST
Where: Winnebago forecast zone
Measured: 40 kt (46 mph) measured sustained
Property damage: $25,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 43.133, -93.483

High Wind, Worth

When: May 24, 5:30 PM CST to 10:30 PM CST
Where: Worth forecast zone
Measured: 40 kt (46 mph) measured sustained
Property damage: $25,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 43.377, -93.261 (the zone’s center; the record gives no point)

High Wind, Wright

When: May 24, 5:30 PM CST to 10:30 PM CST
Where: Wright forecast zone
Measured: 55 kt (63 mph) measured gust
Property damage: $25,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.733, -93.735 (the zone’s center; the record gives no point)

Flash Flood, Marion

When: May 24, 5:30 PM CST to 11:45 PM CST
Where: Marion County, Countywide
Property damage: $100,000
Crop damage: $50,000
Reported by: TRAINED SPOTTER
Coordinates: 41.334, -93.099 (the zone’s center; the record gives no point)

Thunderstorm Wind, Polk

When: May 24, 5:33 PM CST
Where: Polk County, 4 mi W of Polk City
Measured: 61 kt (70 mph) estimated gust
Property damage: $25,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.686, -93.573 (the zone’s center; the record gives no point)

Thunderstorm Wind, Polk

When: May 24, 5:38 PM CST
Where: Polk County, Polk City
Measured: 61 kt (70 mph) estimated gust
Property damage: $25,000
Reported by: TRAINED SPOTTER
Coordinates: 41.686, -93.573 (the zone’s center; the record gives no point)

Thunderstorm Wind, Polk

When: May 24, 5:40 PM CST
Where: Polk County, Polk City
Measured: 61 kt (70 mph) estimated gust
Property damage: $25,000
Reported by: LAW ENFORCEMENT
Coordinates: 40.767, -93.317

Hail, Taylor

When: May 24, 5:40 PM CST
Where: Taylor County, New Market
Measured: 1 in hail
Property damage: $5,000
Crop damage: $5,000
Reported by: EMERGENCY MANAGER
Coordinates: 43.167, -93.200

Thunderstorm Wind, Madison

When: May 24, 5:40 PM CST
Where: Madison County, 1 mi W of Bevington
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: LAW ENFORCEMENT
Coordinates: 40.733, -92.867

Hail, Madison

When: May 24, 5:40 PM CST
Where: Madison County, 1 mi W of Bevington
Measured: 0.75 in hail
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 40.683, -93.117

Thunderstorm Wind, Polk

When: May 24, 5:43 PM CST
Where: Polk County, 4 mi W of Alleman
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: AMATEUR RADIO
Coordinates: 40.733, -92.867

Thunderstorm Wind, Taylor

When: May 24, 5:45 PM CST
Where: Taylor County, Bedford
Measured: 65 kt (75 mph) estimated gust
Property damage: $10,000
Reported by: BROADCAST MEDIA
Coordinates: 40.737, -94.696 (the zone’s center; the record gives no point)

Hail, Taylor

When: May 24, 5:45 PM CST
Where: Taylor County, Bedford
Measured: 1.75 in hail
Property damage: $15,000
Crop damage: $5,000
Reported by: BROADCAST MEDIA
Coordinates: 40.600, -94.400

Flash Flood, Union

When: May 24, 5:45 PM CST to May 25, 12:15 AM CST
Where: Union County, 2 mi NW of Creston
Property damage: $25,000
Crop damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 40.617, -94.383

Hail, Taylor

When: May 24, 5:46 PM CST
Where: Taylor County, 3 mi SE of New Market
Measured: 1.75 in hail
Property damage: $10,000
Crop damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 41.583, -93.017

Thunderstorm Wind, Taylor

When: May 24, 5:46 PM CST
Where: Taylor County, 3 mi SE of New Market
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: TRAINED SPOTTER
Coordinates: 40.737, -94.696 (the zone’s center; the record gives no point)

Hail, Taylor

When: May 24, 5:48 PM CST
Where: Taylor County, 1 mi S of Bedford
Measured: 1 in hail
Property damage: $3,000
Crop damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 40.683, -93.033

Thunderstorm Wind, Warren

When: May 24, 5:48 PM CST
Where: Warren County, Norwalk
Measured: 61 kt (70 mph) estimated gust
Property damage: $10,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.533, -94.567

Flash Flood, Polk

When: May 24, 5:50 PM CST to 10:45 PM CST
Where: Polk County, West Des Moines
Property damage: $50,000
Crop damage: $5,000
Reported by: AMATEUR RADIO
Coordinates: 42.633, -94.600

Thunderstorm Wind, Warren

When: May 24, 5:50 PM CST
Where: Warren County, 1 mi N of Martensdale
Measured: 57 kt (66 mph) estimated gust
Property damage: $10,000
Reported by: LAW ENFORCEMENT
Coordinates: 42.633, -94.483

Thunderstorm Wind, Polk

When: May 24, 5:50 PM CST
Where: Polk County, Des Moines
Measured: 61 kt (70 mph) estimated gust
Property damage: $10,000
Reported by: AMATEUR RADIO
Coordinates: 42.667, -94.450

Hail, Taylor

When: May 24, 5:51 PM CST
Where: Taylor County, 1 mi S of Gravity
Measured: 1.75 in hail
Property damage: $5,000
Crop damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 40.667, -94.717

Hail, Madison

When: May 24, 5:52 PM CST
Where: Madison County, 2 mi NNW of Bevington
Measured: 1.75 in hail
Property damage: $10,000
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 42.467, -95.150

Thunderstorm Wind, Story

When: May 24, 5:52 PM CST
Where: Story County, Slater
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: LAW ENFORCEMENT
Coordinates: 40.600, -94.383

Thunderstorm Wind, Polk

When: May 24, 5:56 PM CST
Where: Polk County, 4 mi N of Ankeny
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: AMATEUR RADIO
Coordinates: 42.067, -93.883

Hail, Taylor

When: May 24, 6:00 PM CST
Where: Taylor County, Bedford
Measured: 1.5 in hail
Property damage: $20,000
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 42.133, -95.333

Thunderstorm Wind, Taylor

When: May 24, 6:00 PM CST
Where: Taylor County, Bedford
Measured: 61 kt (70 mph) estimated gust
Property damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 42.200, -95.317

Flash Flood, Story

When: May 24, 6:00 PM CST to 9:00 PM CST
Where: Story County, Ames
Property damage: $10,000
Reported by: TRAINED SPOTTER
Coordinates: 41.450, -94.767

Thunderstorm Wind, Taylor

When: May 24, 6:00 PM CST
Where: Taylor County, Bedford
Measured: 57 kt (66 mph) estimated gust
Property damage: $15,000
Reported by: NEWSPAPER
Coordinates: 40.737, -94.696 (the zone’s center; the record gives no point)

Thunderstorm Wind, Ringgold

When: May 24, 6:04 PM CST
Where: Ringgold County, Maloy
Measured: 69 kt (79 mph) estimated gust
Property damage: $20,000
Reported by: TRAINED SPOTTER
Coordinates: 41.450, -94.767

Thunderstorm Wind, Ringgold

When: May 24, 6:15 PM CST
Where: Ringgold County, Redding
Measured: 57 kt (66 mph) estimated gust
Property damage: $15,000
Reported by: NEWSPAPER
Coordinates: 41.600, -93.617

Thunderstorm Wind, Ringgold

When: May 24, 6:20 PM CST
Where: Ringgold County, 4 mi S of Benton
Measured: 65 kt (75 mph) estimated gust
Property damage: $10,000
Reported by: TRAINED SPOTTER
Coordinates: 41.467, -94.600

Tornado, Ringgold

When: May 24, 6:20 PM CST
Where: Ringgold County, 4 mi S of Mt Ayr
Rating: F0
Path length: 0.2 mi
Path width: 30 yd
Reported by: EMERGENCY MANAGER
Coordinates: 41.517, -94.450

Brief tornado touchdown in open fields south of Mt Ayr.

Flash Flood, Warren

When: May 24, 6:30 PM CST to May 25, 12:00 AM CST
Where: Warren County, Central Portion
Property damage: $75,000
Crop damage: $10,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.417, -94.133

Thunderstorm Wind, Ringgold

When: May 24, 6:30 PM CST
Where: Ringgold County, 1 mi W of Redding
Measured: 61 kt (70 mph) estimated gust
Property damage: $10,000
Reported by: EMERGENCY MANAGER
Coordinates: 41.583, -93.717

Thunderstorm Wind, Ringgold

When: May 24, 6:33 PM CST
Where: Ringgold County, 1 mi N of Redding
Measured: 61 kt (70 mph) estimated gust
Property damage: $50,000
Reported by: EMERGENCY MANAGER
Coordinates: 41.583, -93.717

Thunderstorm Wind, Marion

When: May 24, 6:36 PM CST
Where: Marion County, Melcher
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.517, -95.050

Flash Flood, Madison

When: May 24, 6:45 PM CST to 10:00 PM CST
Where: Madison County, Countywide
Property damage: $100,000
Crop damage: $50,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.331, -94.016 (the zone’s center; the record gives no point)

Flash Flood, Warren

When: May 24, 6:45 PM CST to 9:45 PM CST
Where: Warren County, 2 mi W of St Marys
Property damage: $50,000
Crop damage: $10,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.550, -94.033

Thunderstorm Wind, Jasper

When: May 24, 6:45 PM CST
Where: Jasper County, Reasnor
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: FIRE DEPT/RESCUE SQUAD
Coordinates: 41.600, -93.617

Thunderstorm Wind, Boone

When: May 24, 6:45 PM CST
Where: Boone County, Boone
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: NEWSPAPER
Coordinates: 41.600, -93.617

Thunderstorm Wind, Decatur

When: May 24, 6:48 PM CST
Where: Decatur County, 1 mi E of Lamoni
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: TRAINED SPOTTER
Coordinates: 41.583, -94.883

Thunderstorm Wind, Cerro Gordo

When: May 24, 6:50 PM CST
Where: Cerro Gordo County, Ventura
Measured: 62 kt (71 mph) estimated gust
Property damage: $2,000
Reported by: LAW ENFORCEMENT
Coordinates: 43.082, -93.261 (the zone’s center; the record gives no point)

Tornado, Appanoose

When: May 24, 6:53 PM CST
Where: Appanoose County, Centerville
Rating: F0
Path length: 0.1 mi
Path width: 25 yd
Property damage: $2,000
Reported by: AMATEUR RADIO
Coordinates: 41.567, -93.750

The tornado was a brief touchdown in open areas. The tornado itself was actually embedded within a large area of straight line winds.

Flash Flood, Adair

When: May 24, 6:55 PM CST to May 25, 12:15 AM CST
Where: Adair County, Adair
Property damage: $75,000
Crop damage: $10,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.500, -94.017

Flash Flood, Union

When: May 24, 6:55 PM CST to May 25, 12:15 AM CST
Where: Union County, Creston
Property damage: $100,000
Crop damage: $25,000
Reported by: TRAINED SPOTTER
Coordinates: 41.517, -93.917

Flash Flood, Greene

When: May 24, 6:55 PM CST to 10:15 PM CST
Where: Greene County, Countywide
Property damage: $100,000
Crop damage: $50,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.433, -93.883

Flash Flood, Story

When: May 24, 6:55 PM CST to 9:55 PM CST
Where: Story County, Maxwell
Property damage: $50,000
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.583, -93.900

Flash Flood, Mahaska

When: May 24, 7:00 PM CST to 8:00 PM CST
Where: Mahaska County, Countywide
Property damage: $50,000
Crop damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.583, -93.717

Flash Flood, Marion

When: May 24, 7:15 PM CST to May 25, 12:45 AM CST
Where: Marion County, Countywide
Property damage: $100,000
Crop damage: $50,000
Reported by: TRAINED SPOTTER
Coordinates: 41.533, -93.883

Thunderstorm Wind, Wayne

When: May 24, 7:19 PM CST
Where: Wayne County, Corydon
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.533, -93.867

Flash Flood, Polk

When: May 24, 7:20 PM CST to 10:45 PM CST
Where: Polk County, Des Moines
Property damage: $75,000
Reported by: TRAINED SPOTTER
Coordinates: 41.517, -94.417

Thunderstorm Wind, Ringgold

When: May 24, 7:25 PM CST
Where: Ringgold County, Redding
Measured: 61 kt (70 mph) estimated gust
Property damage: $10,000
Reported by: LAW ENFORCEMENT
Coordinates: 42.567, -94.517

Thunderstorm Wind, Cerro Gordo

When: May 24, 7:25 PM CST
Where: Cerro Gordo County, 1 mi N of Mason City
Measured: 50 kt (58 mph) estimated gust
Property damage: $5,000
Reported by: TRAINED SPOTTER
Coordinates: 41.617, -93.867

Thunderstorm Wind, Ringgold

When: May 24, 7:26 PM CST
Where: Ringgold County, Maloy
Measured: 69 kt (79 mph) estimated gust
Property damage: $25,000
Reported by: BROADCAST MEDIA
Coordinates: 42.567, -94.383

Thunderstorm Wind, Appanoose

When: May 24, 7:44 PM CST to 7:46 PM CST
Where: Appanoose County, 3 mi W of Numa
Measured: 69 kt (79 mph) estimated gust
Property damage: $100,000
Crop damage: $5,000
Reported by: EMERGENCY MANAGER
Coordinates: 41.467, -93.767

Thunderstorm Wind, Appanoose

When: May 24, 7:45 PM CST
Where: Appanoose County, Centerville
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: LAW ENFORCEMENT
Coordinates: 41.350, -93.800

Thunderstorm Wind, Wayne

When: May 24, 7:47 PM CST
Where: Wayne County, Seymour
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: LAW ENFORCEMENT
Coordinates: 40.740, -93.327 (the zone’s center; the record gives no point)

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.
Tornado: A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.
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.
High Wind: Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.

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

The same day elsewhere

Every storm in Iowa in 2004 Every state in 2004 This day in weather history The tornado archive for Iowa, 2004 Warnings in Iowa, May 2004

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: 5394751, 5394752, 5394753, 5394754, 5393548, 5393460, 5394755, 5394756, 5394757, 5393461, 5393463, 5394758, 5393462, 5394826, 5394827, 5394828, 5394829, 5394830, 5394831, 5394832, 5394833, 5394834, 5394835, 5394836, 5394837, 5394838, 5394839, 5394840, 5394841, 5394842, 5394843, 5394844, 5394845, 5394846, 5394847, 5394848, 5394849, 5394850, 5394851, 5394852, and more.