Iowa, 2004

Tornadoes and Flash Flooding in Iowa, May 22 to 23, 2004

May 22 to 23, 2004 · NWS DMX · 101 events in 22 counties and zones

The synoptic situation was very similar to what it was the previous day. A complex weather situation was in place due to the convection from the previous night.

Where it happened

Every event with a place to put it; 9 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
4
Property damage
$2.6 million
Crop damage
$546,000
Events
101

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.

The synoptic situation was very similar to what it was the previous day. A complex weather situation was in place due to the convection from the previous night. An outflow boundary extended east to west across northern Missouri. The synoptic frontal boundary extended from central Nebraska across northern Iowa. The air was clear over Iowa during the day, allowing for temperatures to recover. Dew point values also recovered quite rapidly with readings in the upper 60s to low 70s by the late afternoon hours. Lifted indices dropped into the -5 to -10 C. range by evening with CAPE values approaching 5000 J/kg. By the evening hours, the frontal boundary and outflow boundary had converged and were located along Interstate 80. Explosive thunderstorm development took place during the very late afternoon and evening hours in spite of the weak shear profile. Discrete supercells formed in a narrow line along Interstate 80 from near Des Moines on west. The storms became tornadic quickly. To add insult to injury, a strong thunderstorm complex formed over Nebraska and moved east along the line of convection over Iowa. As the event took shape, all modes of severe weather occurred. The storms developed so rapidly that there was little more than a half hour from the first hail and wind report to the first tornado touchdown. Hail and high wind reports were too numerous to mention individually here. Numerous reports of golf ball size hail were received. Boone and Story Counties reported some of the largest hail with the event as baseball size hail pelted the are. There was one report of very large hail northwest of Slater in Story County. Hail five and one half inches in diameter punched 8 holes through a steel roof. There was severe house siding and roof damage in the area. There were numerous tornadoes, especially in the central Iowa Iowa. At one point there were several supercells around the metropolitan Des Moines area. Two of the stronger tornadoes touched down west and south of Des Moines. Fortunately, most of the tornado tracks were over open areas and resulted in little damage. High winds became a problem, especially after sunset, as the complex from Nebraska moved in. The system became more of a derecho during the late night hours. Eighty plus MPH winds pelted southwest Iowa and downed barns and several buildings in Adams and Cass Counties. A beta bow element formed in central Iowa shortly before midnight. The bow echo produced a measured wind gust of 106 MPH in northern Warren County. The high winds continued to push east along Interstate 80 for the next hour or so before it started to weaken. The other major problem was with heavy rain. The convection from the previous night set the stage by saturating soils. The echos trained for several hours across central Iowa with very heavy rainfall. Rainfall rates of 4 to 5 inches per hour were common under the heavier cells. Several locations received 2 to 5 inch rainfalls in under two hours, resulting in widespread flash flooding. Reports of major highways being inundated by water were common. By the end of the night, a swath of 4 to 9 inch rainfall was evident north of Interstate 80. Longer term river flooding became a major problem by the morning of the 23rd. There were two lightning related injuries. Two people were injured when they were struck by lightning out of doors in Nevada. The lightning struck close by as they were carrying groceries into their home. The jolt caused them to fall, resulting in laceration to the head.

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 22, 1:09 PM CST, 4 hours 23 minutes earlier.

Area forecast discussion, May 22, 1:09 PM CST, 4 hours 23 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
209 PM CDT SAT MAY 22 2004

.DISCUSSION...
MAIN CONCERNS FOR EARLY IN THE FORECAST PERIOD WILL BE CONVECTION
THROUGH MONDAY. TODAY OUTFLOW BOUNDARY FROM MORNING CONVECTION
BEGINNING TO ERODE OVER NORTHERN MISSOURI WITH A MORE SOUTHERLY PUSH
BECOMING APPARENT. NEXT IN ROUND OF SHORTWAVES NOW ENTERING MIDWEST.
STATIONARY BOUNDARY OVER NORTHERN IOWA BEGINNING TO SAG SOUTH WITH
BOUNDARIES PRIMED TO CONVERGE. EXPLOSIVE THUNDERSTORM DEVELOPMENT
APPEARS LIKELY AND FROM 18Z OAX SOUNDING...CAP IS ERODING.
SUPERCELLS ARE LIKELY WITHIN THE FIRST SEVERAL HOURS OF INITIATION
LATE THIS AFTERNOON AND EVENING. LARGE HAIL AND TORNADOES WILL BE
THE MAIN THREATS EARLY ON. HEAVY RAIN WILL BE A CONCERN WITH THE
POSSIBILITY OF TRAINING STORMS EARLY. 65-70KT 850MB JET CRANKS UP
TONIGHT WITH GOOD CONVERGENCE OVER IOWA AND PLENTY OF MOISTURE FEED.
CONVECTION SHOULD FORM INTO AN MCS AND TRAVEL ACROSS THE
NORTHWESTERN 2/3 OF THE FORECAST AREA. WIDESPREAD 1-2 INCH AMOUNTS
LIKELY WITH LOCALLY HEAVIER POSSIBLE.  LOW TRACKS ACROSS CNTRL IA
SUNDAY...POSSIBLE THUNDERSTORMS DEVELOPING ALONG COLD FRONT ACROSS
EAST. MORE THUNDERSTORMS EXPECTED MONDAY AS NEXT SYSTEM ARRIVES.

ACTIVITY FINALLY COMES TO AN END BY TUESDAY WITH COOLER AND DRY
CONDITIONS EXPECTED. KEPT NEXT CHANCE FOR PRECIPITATION FRIDAY.
ENSEMBLES NOT IN AGREEMENT ON SHORTWAVE TOWARDS THE END OF THE WEEK
AND REMAIN CONSISTENT FOR END OF EXTENDED PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...FLOOD WATCH TONIGHT NORTH OF
INTERSTATE 80.

&&

DONAVON
Hazardous weather outlook, May 22, 2:27 PM CST, 3 hours 5 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
327 PM CDT SAT MAY 22 2004

IAZ004>007-015>017-024>028-036>039-048>050-060>062-231100-
BLACK HAWK-BREMER-BUTLER-CERRO GORDO-EMMET-FRANKLIN-GRUNDY-HAMILTON-
HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH-MARSHALL-PALO ALTO-POLK-
POWESHIEK-STORY-TAMA-WINNEBAGO-WORTH-WRIGHT-
327 PM CDT SAT MAY 22 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MUCH OF CENTRAL AND NORTHERN
IOWA...NORTH AND EAST OF A LINE FROM EMMETSBURG...TO DES MOINES...TO
GRINNELL.

.DAY ONE...TONIGHT

THERE IS A MODERATE RISK OF SEVERE WEATHER FROM 6 PM TONIGHT
THROUGH THE REST OF THE NIGHT.  THREATS INCLUDE VERY LARGE HAIL AND
DAMAGING STRAIGHT LINE WINDS. ISOLATED TORNADOES ARE ALSO POSSIBLE
DURING THE EVENING HOURS. FLASH FLOODING IS ALSO POSSIBLE...
ESPECIALLY ACROSS AREAS ALONG AND NORTH OF HIGHWAY 20 THAT WERE HARD
HIT BY RECENT RAINS. ISOLATED 3 TO 5 INCH RAINFALL TOTALS ARE
POSSIBLE BY SUNDAY MORNING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

A THUNDERSTORM COMPLEX...WITH SOME EMBEDDED SEVERE
THUNDERSTORMS POSSIBLE...WILL LIKELY BE ONGOING EARLY SUNDAY
MORNING. SEVERE WEATHER IS POSSIBLE AGAIN SUNDAY AFTERNOON AND
MONDAY AFTERNOON AND NIGHT.

.SPOTTER ACTIVATION STATEMENT...

SPOTTER ACTIVATION WILL BE NEEDED TONIGHT FOR BOTH SEVERE WEATHER AND
FLOODING REPORTS. SPOTTER ACTIVATION MAY ALSO BE NEEDED AGAIN ON
SUNDAY AND MONDAY.

IAZ023-033>035-044>047-057>059-231100-
AUDUBON-BOONE-CALHOUN-CARROLL-CRAWFORD-DALLAS-GREENE-GUTHRIE-
POCAHONTAS-SAC-WEBSTER-
327 PM CDT SAT MAY 22 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A PORTION OF WEST
CENTRAL INTO CENTRAL IOWA...ALONG AND WEST OF A LINE FROM AUDUBON...
TO PERRY...TO POCAHONTAS.

.DAY ONE...TONIGHT

THERE IS A MODERATE RISK OF SEVERE WEATHER FROM 600 PM THROUGH
THE NIGHT. THREATS INCLUDE VERY LARGE HAIL AND DAMAGING STRAIGHT LINE
WINDS. CONDITIONS ARE ALSO VERY FAVORABLE FOR TORNADOES DURING THE
EVENING. FLASH FLOODING IS ALSO POSSIBLE...ESPECIALLY ACROSS AREAS
ALONG AND NORTH OF HIGHWAY 20 THAT WERE HARD HIT BY RECENT RAINS.
ISOLATED 3 TO 5 INCH RAINFALL TOTALS ARE POSSIBLE BY SUNDAY MORNING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SEVERE THUNDERSTORMS ARE POSSIBLE MONDAY AFTERNOON AND NIGHT.

.SPOTTER ACTIVATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED TONIGHT FOR BOTH SEVERE
WEATHER AND FLOODING REPORTS. SPOTTER ACTIVATION MAY ALSO BE NEEDED
MONDAY AFTERNOON AND NIGHT.

IAZ073>075-084>086-092>097-231100-
APPANOOSE-DAVIS-DECATUR-LUCAS-MAHASKA-MARION-MONROE-RINGGOLD-TAYLOR-
WAPELLO-WARREN-WAYNE-
327 PM CDT SAT MAY 22 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MUCH OF SOUTHERN IOWA.

.DAY ONE...TONIGHT

THERE IS A MODERATE RISK OF SEVERE WEATHER FROM 600 PM TONIGHT
THROUGH THE REST OF THE NIGHT.  THREATS INCLUDE VERY LARGE HAIL AND
DAMAGING STRAIGHT LINE WINDS.  CONDITIONS ARE ALSO FAVORABLE FOR
STRONG TORNADOES.  EVENING HOURS. ISOLATED FLASH FLOODING CANNOT BE
RULED OUT...BUT IS NOT LIKELY.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SEVERE THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON AND AGAIN
MONDAY AFTERNOON AND NIGHT.

.SPOTTER ACTIVATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TONIGHT. SPOTTER ACTIVATION MAY ALSO
BE NEEDED AGAIN ON SUNDAY AFTERNOON AND MONDAY.

IAZ070>072-081>083-231100-
ADAIR-ADAMS-CASS-CLARKE-MADISON-UNION-
327 PM CDT SAT MAY 22 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A PORTION OF SOUTHERN IOWA.

.DAY ONE...TONIGHT

THERE IS A MODERATE RISK OF SEVERE WEATHER FROM 600 PM THIS
EVENING THROUGH THE REST OF THE NIGHT.  THREATS INCLUDE VERY LARGE
HAIL AND DAMAGING STRAIGHT LINE WINDS. CONDITIONS ARE ALSO VERY
FAVORABLE FOR STRONG TORNADOES DURING THE EVENING. ISOLATED FLASH
FLOODING CANNOT BE RULED OUT...BUT IS NOT LIKELY.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SEVERE WEATHER IS POSSIBLE MONDAY AFTERNOON AND NIGHT.

.SPOTTER ACTIVATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED TONIGHT. SPOTTER ACTIVATION
MAY ALSO BE NEEDED MONDAY AFTERNOON AND NIGHT.

In the hours before

Local storm report, May 22, 4:41 PM CST, 51 minutes before
PRELIMINARY LOCAL STORM REPORT ... SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
541 PM CDT SAT MAY 22 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

1115 AM     HAIL             BRITT                   43.10N 93.80W
05/21/2004  0.88 INCH        HANCOCK            IA   PUBLIC

1125 AM     HAIL             5 NW NORTHWOOD          43.50N 93.29W
05/21/2004  1.00 INCH        WORTH              IA   LAW ENFORCEMENT

1125 AM     HAIL             BRITT                   43.10N 93.80W
05/21/2004  1.00 INCH        HANCOCK            IA   TRAINED SPOTTER

1130 AM     HAIL             2 E RUTHVEN             43.13N 94.86W
05/21/2004  1.75 INCH        PALO ALTO          IA   BROADCAST MEDIA

            REPORT RECEIVED FROM KICD RADIO

1131 AM     HAIL             RUTHVEN                 43.13N 94.90W
05/21/2004  1.00 INCH        PALO ALTO          IA   LAW ENFORCEMENT

1140 AM     HAIL             1 S NORTHWOOD           43.43N 93.22W
05/21/2004  0.75 INCH        WORTH              IA   TRAINED SPOTTER

1235 PM     HAIL             3 W GREENE              42.90N 92.86W
05/21/2004  0.75 INCH        BUTLER             IA   TRAINED SPOTTER

0152 PM     HAIL             STEAMBOAT ROCK          42.41N 93.07W
05/21/2004  0.88 INCH        HARDIN             IA   TRAINED SPOTTER

            REPORTED BY TRAINED SPOTTER.

0220 PM     HAIL             WEBSTER CITY            42.46N 93.82W
05/21/2004  1.00 INCH        HAMILTON           IA   TRAINED SPOTTER

0221 PM     HAIL             2 E DOWS                42.66N 93.46W
05/21/2004  0.75 INCH        FRANKLIN           IA   TRAINED SPOTTER

0228 PM     TORNADO          2 W HOLLAND             42.40N 92.84W
05/21/2004                   GRUNDY             IA   LAW ENFORCEMENT

0231 PM     HAIL             SE POPEJOY              42.59N 93.43W
05/21/2004  0.88 INCH        FRANKLIN           IA   TRAINED SPOTTER

0232 PM     TORNADO          3 W HOLLAND             42.40N 92.86W
05/21/2004                   GRUNDY             IA   AMATEUR RADIO

0232 PM     TORNADO          1 E HOLLAND             42.40N 92.78W
05/21/2004                   GRUNDY             IA   AMATEUR RADIO

            CORRECTION ON LOCATION...ORIGINAL REPORT HAD 3 WEST OF
            HOLLAND AND IT SHOULD BE 1 EAST OF HOLLAND.

0238 PM     TORNADO          3 N GRUNDY CENTER       42.41N 92.77W
05/21/2004                   GRUNDY             IA   LAW ENFORCEMENT

            TORNADO CROSSING HIGHWAY 14 WITH DEBRIS. STATE PATROL
            REPORT.

0242 PM     HAIL             DIKE                    42.46N 92.63W
05/21/2004  0.88 INCH        GRUNDY             IA   AMATEUR RADIO

0242 PM     TORNADO          4 NE GRUNDY CENTER      42.40N 92.72W
05/21/2004                   GRUNDY             IA   LAW ENFORCEMENT

            STATE PATROL REPORT OF TWO SIMULATNEOUS TORNADOES.

0249 PM     TORNADO          7 SW DIKE               42.39N 92.73W
05/21/2004                   GRUNDY             IA   TRAINED SPOTTER

            MOVING NORTHEAST TOWARD DIKE.

0250 PM     HAIL             ALDEN                   42.51N 93.38W
05/21/2004  1.00 INCH        HARDIN             IA   TRAINED SPOTTER

0253 PM     HAIL             2 NW DIKE               42.48N 92.66W
05/21/2004  1.75 INCH        GRUNDY             IA   LAW ENFORCEMENT

0253 PM     TSTM WND DMG     9 E POPEJOY             42.59N 93.25W
05/21/2004                   FRANKLIN           IA   PUBLIC

            OUTBUILDINGS DAMAGED. TREES DOWN.

0300 PM     HAIL             ALDEN                   42.51N 93.38W
05/21/2004  1.00 INCH        HARDIN             IA   LAW ENFORCEMENT

0306 PM     HAIL             GRUNDY CENTER           42.36N 92.77W
05/21/2004  0.88 INCH        GRUNDY             IA   TRAINED SPOTTER

0315 PM     TORNADO          10 W GRUNDY CENTER      42.36N 92.97W
05/21/2004                   GRUNDY             IA   AMATEUR RADIO

            ON STATE HIGHWAY 175

0315 PM     HAIL             TRAER                   42.19N 92.46W
05/21/2004  1.25 INCH        TAMA               IA   TRAINED SPOTTER

0316 PM     HAIL             TRAER                   42.19N 92.46W
05/21/2004  1.00 INCH        TAMA               IA   LAW ENFORCEMENT

0317 PM     HAIL             DIKE                    42.46N 92.63W
05/21/2004  1.00 INCH        GRUNDY             IA   TRAINED SPOTTER

0321 PM     TORNADO          3 S WATERLOO            42.45N 92.35W
05/21/2004                   BLACK HAWK         IA   PUBLIC

0321 PM     HAIL             WATERLOO                42.49N 92.35W
05/21/2004  1.00 INCH        BLACK HAWK         IA   TRAINED SPOTTER

            NICKEL TO QUARTER SIZED HAIL REPORTED BY TRAINED SPOTTER.

0321 PM     HAIL             WATERLOO                42.49N 92.35W
05/21/2004  1.00 INCH        BLACK HAWK         IA   TRAINED SPOTTER

0322 PM     TORNADO          5 NW GRUNDY CENTER      42.41N 92.84W
05/21/2004                   GRUNDY             IA   AMATEUR RADIO

0330 PM     HAIL             WATERLOO                42.49N 92.35W
05/21/2004  1.75 INCH        BLACK HAWK         IA   BROADCAST MEDIA

0333 PM     TSTM WND GST     4 NW CEDAR FALLS        42.56N 92.51W
05/21/2004  60 MPH           BLACK HAWK         IA   LAW ENFORCEMENT

0335 PM     TSTM WND DMG     EVANSDALE               42.46N 92.28W
05/21/2004                   BLACK HAWK         IA   AMATEUR RADIO

            TREES DOWN ON LAFAYETTE ST.

0341 PM     HAIL             WATERLOO                42.49N 92.35W
05/21/2004  0.88 INCH        BLACK HAWK         IA   LAW ENFORCEMENT

0342 PM     HAIL             GRUNDY CENTER           42.36N 92.77W
05/21/2004  1.75 INCH        GRUNDY             IA   LAW ENFORCEMENT

            HIGHWAY 175 WEST OF GRUNDY CENTER

0345 PM     HAIL             1 SE RAYMOND            42.46N 92.21W
05/21/2004  0.88 INCH        BLACK HAWK         IA   EMERGENCY MNGR

0345 PM     HAIL             4 SE WATERLOO           42.45N 92.30W
05/21/2004  0.88 INCH        BLACK HAWK         IA   EMERGENCY MNGR

            ESTIMATED 4 MI SE OF WATERLOO, MM65, I380

0404 PM     HAIL             WATERLOO                42.49N 92.35W
05/21/2004  0.75 INCH        BLACK HAWK         IA   TRAINED SPOTTER

0410 PM     TSTM WND DMG     2 N TRAER               42.22N 92.46W
05/21/2004                   TAMA               IA   TRAINED SPOTTER

            NUMEROUS TREES DOWN 1-2 MI NORTH OF TRAER

0416 PM     HAIL             TRAER                   42.19N 92.46W
05/21/2004  1.00 INCH        TAMA               IA   TRAINED SPOTTER

0420 PM     HAIL             2 NW DYSART             42.19N 92.34W
05/21/2004  0.88 INCH        TAMA               IA   TRAINED SPOTTER

0423 PM     TSTM WND GST     3 N CLUTIER             42.12N 92.40W
05/21/2004  60 MPH           TAMA               IA   TRAINED SPOTTER

0539 PM     HAIL             5 N MESERVEY            42.98N 93.46W
05/21/2004  1.00 INCH        CERRO GORDO        IA   TRAINED SPOTTER

0555 PM     HAIL             CLEAR LAKE              43.14N 93.37W
05/21/2004  1.00 INCH        CERRO GORDO        IA   NWS EMPLOYEE

0557 PM     HAIL             2 E PLAINFIELD          42.84N 92.50W
05/21/2004  1.00 INCH        BREMER             IA   TRAINED SPOTTER

            DELAYED REPORT.

0600 PM     HAIL             1 SSW GRUNDY CENTER     42.36N 92.78W
05/21/2004  0.75 INCH        GRUNDY             IA   TRAINED SPOTTER

0602 PM     HAIL             N CLEAR LAKE            43.13N 93.38W
05/21/2004  0.88 INCH        CERRO GORDO        IA   TRAINED SPOTTER

0602 PM     HAIL             GRUNDY CENTER           42.36N 92.77W
05/21/2004  1.75 INCH        GRUNDY             IA   LAW ENFORCEMENT

            WEST SIDE OF CITY.

0607 PM     HAIL             5 NNE MESERVEY          42.97N 93.42W
05/21/2004  0.88 INCH        CERRO GORDO        IA   TRAINED SPOTTER

0609 PM     HAIL             2 E PLAINFIELD          42.84N 92.50W
05/21/2004  1.00 INCH        BREMER             IA   TRAINED SPOTTER

0610 PM     TORNADO          1 E ROLFE               42.81N 94.53W
05/21/2004                   POCAHONTAS         IA   LAW ENFORCEMENT

            RELAYED VIA AMATEUR RADIO.

0610 PM     TORNADO          ROLFE                   42.81N 94.53W
05/21/2004                   POCAHONTAS         IA   LAW ENFORCEMENT

            THREE TORNADOES. NUMEROUS INJURIES. CONSIDERABLE PROPERTY
            DAMAGE.

0615 PM     FLOOD            ALGONA                  43.07N 94.23W
05/21/2004                   KOSSUTH            IA   EMERGENCY MNGR

            ROADS UNDERWATER THROUGHOUT SOUTHERN KOSSUTH COUNTY. 3
            FEET OF WATER OVER SEVERAL ROADS. CARS STALLED ALONG
            HIGHWAY 18 IN ALGONA.

0622 PM     TORNADO          2 E ROLFE               42.81N 94.49W
05/21/2004                   POCAHONTAS         IA   AMATEUR RADIO

0623 PM     TORNADO          BRADGATE                42.80N 94.42W
05/21/2004                   HUMBOLDT           IA   BROADCAST MEDIA

            HOMES DAMAGED AND INJURIES.

0640 PM     HAIL             4 SW ALGONA             43.03N 94.29W
05/21/2004  1.00 INCH        KOSSUTH            IA   EMERGENCY MNGR

            FIELDS AND DITCHES FLOODED DUE TO HEAVY RAIN.

0646 PM     HAIL             1 S ROLFE               42.80N 94.53W
05/21/2004  0.75 INCH        POCAHONTAS         IA   STORM CHASER

            RELAYED VIA AMATEUR RADIO.

0652 PM     HAIL             4 N NEW HARTFORD        42.62N 92.63W
05/21/2004  1.00 INCH        BUTLER             IA   TRAINED SPOTTER

0655 PM     HAIL             RENWICK                 42.83N 93.98W
05/21/2004  1.00 INCH        HUMBOLDT           IA   STORM CHASER

0712 PM     HAIL             KANAWHA                 42.93N 93.79W
05/21/2004  0.88 INCH        HANCOCK            IA   TRAINED SPOTTER

0726 PM     FLOOD            6 SW MASON CITY         43.09N 93.28W
05/21/2004                   CERRO GORDO        IA   AMATEUR RADIO

            WATER COVERING ROADS. VISIBLE FROM INTERSTATE 35.

0730 PM     TORNADO          6 NW CLARION            42.79N 93.82W
05/21/2004                   WRIGHT             IA   PUBLIC

            RELAYED FROM LAW ENFORCEMENT. DELAYED REPORT.

0730 PM     TSTM WND GST     4 W CLARION             42.73N 93.81W
05/21/2004  60 MPH           WRIGHT             IA   LAW ENFORCEMENT

            DELAYED REPORT.

0733 PM     FLOOD            GOODELL                 42.92N 93.61W
05/21/2004                   HANCOCK            IA   AMATEUR RADIO

            WATER COVERING ROADS AND FIELDS.

0735 PM     HAIL             NNW CLARION             42.73N 93.73W
05/21/2004  0.88 INCH        WRIGHT             IA   LAW ENFORCEMENT

            DELAYED REPORT.

0801 PM     FLOOD            GOODELL                 42.92N 93.61W
05/21/2004                   HANCOCK            IA   TRAINED SPOTTER

            WATER OVER 130TH STREET AT HIGHWAY 69.

0803 PM     FLOOD            S MASON CITY            43.15N 93.20W
05/21/2004                   CERRO GORDO        IA   LAW ENFORCEMENT

            WATER OVER ROADS OVER SOUTHERN PART OF CERRO GORDO
            COUNTY. ALONG HIGHWAY 65, 2 TO 3 INCHES DEEP AND CLIMBING
            BETWEEN THE AVENUE OF THE SAINTS AND ROCKWELL.

0803 PM     HEAVY RAIN       N ROCKWELL              42.99N 93.19W
05/21/2004  2.50 INCH        CERRO GORDO        IA   TRAINED SPOTTER

            IN LESS THAN ONE HOUR.

0805 PM     TSTM WND DMG     4 S DOWS                42.60N 93.50W
05/21/2004                   WRIGHT             IA   EMERGENCY MNGR

            BARN AND GRAIN BINDS DESTROYED

0815 PM     FLASH FLOOD      4 N CLARKSVILLE         42.84N 92.67W
05/21/2004                   BUTLER             IA   LAW ENFORCEMENT

            WATER OVER ROAD ... UNKNOWN DEPTH

0819 PM     TSTM WND GST     4 W WAVERLY             42.73N 92.55W
05/21/2004  60 MPH           BREMER             IA   TRAINED SPOTTER

0823 PM     TSTM WND GST     WAVERLY                 42.73N 92.47W
05/21/2004  60 MPH           BREMER             IA   TRAINED SPOTTER

0835 PM     FLOOD            WAVERLY                 42.73N 92.47W
05/21/2004                   BREMER             IA   TRAINED SPOTTER

            STREET FLOODING. 3 TO 6 INCHES OF STANDING WATER.

0850 PM     TSTM WND GST     1 SE READLYN            42.69N 92.21W
05/21/2004  60 MPH           BREMER             IA   TRAINED SPOTTER

0852 PM     FLASH FLOOD      1 NW FREDERIKA          42.89N 92.32W
05/21/2004                   BREMER             IA   PUBLIC

            CORRECTION TO PREVIOUS REPORT...BREMER COUNTY...1 1/2
            FOOT WATER AND DEBRIS OVER HIGHWAY 63

0943 PM     FLASH FLOOD      ALLISON                 42.75N 92.80W
05/21/2004                   BUTLER             IA   EMERGENCY MNGR

            BUTLER COUNTY FLOOD WATERS OVER LESSER MAINTAINED COUNTY
            ROADS AND CULVERTS...MAIN ROADS NOT FLOODED

0943 PM     TSTM WND DMG     WAVERLY                 42.73N 92.47W
05/21/2004                   BREMER             IA   EMERGENCY MNGR

            WAVERLY WITHOUT POWER DUE TO SEVERE THUNDERSTORM
            LIGHTNING AND WIND DAMAGE

1033 PM     FLOOD            2 N SHELL ROCK          42.74N 92.58W
05/21/2004                   BUTLER             IA   TRAINED SPOTTER

            ON COUNTY ROAD T63, DITCHES AND SEVERAL FIELDS FULL WITH
            WATER. DRIVEWAYS COVERED WITH WATER. FEW STREETS IN NEW
            HARTFORD COVERED UNDER 2 TO 4 INCHES OF WATER.

1045 PM     FLASH FLOOD      CLARKSVILLE             42.78N 92.67W
05/21/2004                   BUTLER             IA   FIRE DEPT/RESCUE

            FLOODING OCCURRED ON COUNTY ROADS WITH SOME GRAVEL ROADS
            WASHED OUT.

1059 PM     HAIL             MALLARD                 42.94N 94.68W
05/21/2004  0.75 INCH        PALO ALTO          IA   BROADCAST MEDIA

1102 PM     HAIL
           MANLY                   43.29N 93.20W
05/21/2004  1.00 INCH        WORTH              IA   BROADCAST MEDIA

1120 PM     FLASH FLOOD      ROCKWELL                42.98N 93.19W
05/21/2004                   CERRO GORDO        IA   LAW ENFORCEMENT

            NUMEROUS ROADS FLOODED WITH AFFECTED AREA EXPANDING INTO
            SOUTHWEST PORTION OF COUNTY. SOME GRAVEL ROADS WASHED OUT
            IN PAST HOUR.

1135 PM     FLASH FLOOD      MASON CITY              43.15N 93.20W
05/21/2004                   CERRO GORDO        IA   EMERGENCY MNGR

            EVACUATIONS OCCURRING DUE TO RAPID FLOODING. DETAILS
            UNKNOWN.

1220 AM     FLASH FLOOD      JOICE                   43.36N 93.46W
05/22/2004                   WORTH              IA   LAW ENFORCEMENT

            MAIN STREET FLOODED.

1220 AM     FLASH FLOOD      2 E HANLONTOWN          43.28N 93.34W
05/22/2004                   WORTH              IA   LAW ENFORCEMENT

            WATER FLOWING OVER COUNTY ROADS ADJACENT TO I-35 IN
            SOUTHERN 10 MILES OF COUNTY.

1235 AM     FLASH FLOOD      EAGLE GROVE             42.67N 93.90W
05/22/2004                   WRIGHT             IA   BROADCAST MEDIA

            2-3 FEET OF WATER ON SOME SIDE STREETS.

0144 AM     TSTM WND GST     TRIPOLI                 42.81N 92.26W
05/22/2004  64 MPH           BREMER             IA   MESONET

0508 AM     TSTM WND GST     ATLANTIC                41.40N 95.01W
05/22/2004  60 MPH           CASS               IA   AWOS

&&
ROLFE TORNADO WAS RATED F1.  BRADGATE F2.   FULL EVENT NARRATIVE WILL
BE ISSUED LATER THIS EVENING.

KJ

The radar

The Des Moines radar (KDMX), 100 km away, was scanning. The volume nearest the first event began at 23:30 UTC.

Open the radar archive at this moment

Event by event

39 thunderstorm wind, 35 hail, 18 tornado, 8 flash flood, 1 lightning. Local standard time, as filed.

Hail, Boone

When
May 22, 5:32 PM CST
Where
Boone County, 7 mi SW of Boone
Measured
0.88 in hail
Property damage
$1,000
Crop damage
$5,000
Reported by
LAW ENFORCEMENT
Coordinates
42.133, -94.800

Thunderstorm Wind, Carroll

When
May 22, 5:35 PM CST
Where
Carroll County, Manning
Measured
69 kt (79 mph) estimated gust
Property damage
$10,000
Reported by
TRAINED SPOTTER
Coordinates
41.917, -93.850

Hail, Carroll

When
May 22, 5:42 PM CST
Where
Carroll County, 1 mi N of Templeton
Measured
0.88 in hail
Property damage
$1,000
Crop damage
$5,000
Reported by
TRAINED SPOTTER
Coordinates
41.883, -93.850

Hail, Carroll

When
May 22, 5:51 PM CST
Where
Carroll County, 6 mi NE of Carroll
Measured
1.75 in hail
Property damage
$5,000
Crop damage
$5,000
Reported by
TRAINED SPOTTER
Coordinates
41.883, -93.850

Hail, Boone

When
May 22, 5:58 PM CST
Where
Boone County, 2 mi N of Madrid
Measured
2.75 in hail
Property damage
$15,000
Crop damage
$5,000
Reported by
LAW ENFORCEMENT
Coordinates
42.033, -93.617

Hail, Boone

When
May 22, 5:59 PM CST
Where
Boone County, Madrid
Measured
0.88 in hail
Property damage
$1,000
Crop damage
$5,000
Reported by
NWS EMPLOYEE(OFF DUTY)
Coordinates
41.883, -93.850

Hail, Boone

When
May 22, 5:59 PM CST
Where
Boone County, Madrid
Measured
1.75 in hail
Property damage
$10,000
Crop damage
$3,000
Reported by
AMATEUR RADIO
Coordinates
42.033, -93.617

Hail, Story

When
May 22, 6:01 PM CST
Where
Story County, Ames
Measured
0.88 in hail
Property damage
$5,000
Crop damage
$3,000
Reported by
AMATEUR RADIO
Coordinates
41.933, -93.700

Hail, Boone

When
May 22, 6:02 PM CST
Where
Boone County, Madrid
Measured
2.75 in hail
Property damage
$25,000
Crop damage
$3,000
Reported by
BROADCAST MEDIA
Coordinates
41.433, -94.467

Hail, Story

When
May 22, 6:03 PM CST
Where
Story County, Ames
Measured
1 in hail
Property damage
$5,000
Crop damage
$3,000
Reported by
AMATEUR RADIO
Coordinates
41.900, -94.717

Hail, Story

When
May 22, 6:05 PM CST
Where
Story County, 1 mi SW of Kelley
Measured
1.75 in hail
Property damage
$5,000
Crop damage
$5,000
Reported by
EMERGENCY MANAGER
Coordinates
41.500, -94.233

Tornado, Adair

When
May 22, 6:07 PM CST to 6:24 PM CST
Where
Adair County, 9 mi N of Greenfield
Rating
F1
Path length
7.1 mi
Path width
100 yd
Property damage
$50,000
Crop damage
$10,000
Reported by
STORM CHASER
Coordinates
42.033, -93.617

Tornado touched down southwest of the town of Stuart and tracked northeast through mostly open countryside. The tornado did lift occasionally.

Hail, Carroll

When
May 22, 6:10 PM CST
Where
Carroll County, 3 mi NW of Coon Rapids
Measured
1.75 in hail
Property damage
$5,000
Crop damage
$5,000
Reported by
TRAINED SPOTTER
Coordinates
42.050, -93.633

Tornado, Madison

When
May 22, 6:11 PM CST
Where
Madison County, 5 mi W of Earlham
Rating
F0
Path length
0.3 mi
Path width
30 yd
Reported by
LAW ENFORCEMENT
Coordinates
41.867, -94.683

Brief touchdown in open field.

Hail, Story

When
May 22, 6:11 PM CST
Where
Story County, Ames
Measured
1 in hail
Property damage
$3,000
Crop damage
$3,000
Reported by
TRAINED SPOTTER
Coordinates
41.883, -93.700

Hail, Story

When
May 22, 6:15 PM CST
Where
Story County, 1 mi NW of Ames
Measured
0.88 in hail
Property damage
$1,000
Crop damage
$3,000
Reported by
GENERAL PUBLIC
Coordinates
42.017, -93.617

Hail, Greene

When
May 22, 6:15 PM CST to 6:20 PM CST
Where
Greene County, 7 mi SSW of Scranton
Measured
2 in hail
Property damage
$10,000
Crop damage
$5,000
Reported by
GENERAL PUBLIC
Coordinates
41.767, -94.783

Hail, Carroll

When
May 22, 6:17 PM CST
Where
Carroll County, Coon Rapids
Measured
1.75 in hail
Property damage
$15,000
Crop damage
$5,000
Reported by
FIRE DEPT/RESCUE SQUAD
Coordinates
42.033, -93.617

Hail, Carroll

When
May 22, 6:17 PM CST
Where
Carroll County, 4 mi N of Coon Rapids
Measured
2.75 in hail
Property damage
$15,000
Crop damage
$5,000
Reported by
GENERAL PUBLIC
Coordinates
41.683, -94.700

Hail, Story

When
May 22, 6:18 PM CST
Where
Story County, 1 mi W of Slater
Measured
2.75 in hail
Property damage
$10,000
Crop damage
$5,000
Reported by
AMATEUR RADIO
Coordinates
42.033, -93.617

Hail, Story

When
May 22, 6:20 PM CST
Where
Story County, 1 mi S of Ames
Measured
0.88 in hail
Property damage
$3,000
Crop damage
$5,000
Reported by
TRAINED SPOTTER
Coordinates
42.033, -93.617

Hail, Story

When
May 22, 6:20 PM CST
Where
Story County, 1 mi NW of Slater
Measured
5.5 in hail
Property damage
$100,000
Crop damage
$10,000
Reported by
FIRE DEPT/RESCUE SQUAD
Coordinates
41.933, -94.600

Hail, Greene

When
May 22, 6:20 PM CST
Where
Greene County, 7 mi SSW of Scranton
Measured
2.5 in hail
Property damage
$15,000
Crop damage
$5,000
Reported by
GENERAL PUBLIC
Coordinates
41.717, -94.783

Hail, Story

When
May 22, 6:25 PM CST
Where
Story County, Ames
Measured
1 in hail
Property damage
$5,000
Crop damage
$3,000
Reported by
GENERAL PUBLIC
Coordinates
41.900, -94.783

Hail, Story

When
May 22, 6:26 PM CST
Where
Story County, Ames
Measured
1 in hail
Property damage
$5,000
Crop damage
$3,000
Reported by
TRAINED SPOTTER
Coordinates
41.867, -94.683

Hail, Story

When
May 22, 6:28 PM CST
Where
Story County, Ames
Measured
1.75 in hail
Property damage
$25,000
Crop damage
$3,000
Reported by
GENERAL PUBLIC
Coordinates
41.883, -93.417

Hail, Audubon

When
May 22, 6:30 PM CST
Where
Audubon County, 8 mi ENE of Audubon
Measured
1 in hail
Property damage
$5,000
Crop damage
$5,000
Reported by
TRAINED SPOTTER
Coordinates
41.683, -94.700

Hail, Guthrie

When
May 22, 6:30 PM CST
Where
Guthrie County, 10 mi W of Guthrie Center
Measured
0.88 in hail
Property damage
$1,000
Crop damage
$5,000
Reported by
TRAINED SPOTTER
Coordinates
41.567, -92.983

Hail, Guthrie

When
May 22, 6:30 PM CST
Where
Guthrie County, 7 mi S of Panora
Measured
3.5 in hail
Property damage
$15,000
Crop damage
$5,000
Reported by
NEWSPAPER
Coordinates
41.933, -94.950

Hail, Audubon

When
May 22, 6:35 PM CST
Where
Audubon County, 8 mi E of Audubon
Measured
1.75 in hail
Property damage
$10,000
Crop damage
$25,000
Reported by
TRAINED SPOTTER
Coordinates
41.583, -92.983

Hail, Carroll

When
May 22, 6:41 PM CST
Where
Carroll County, 2 mi E of Dedham
Measured
1.75 in hail
Property damage
$5,000
Crop damage
$5,000
Reported by
LAW ENFORCEMENT
Coordinates
41.517, -94.150

Hail, Carroll

When
May 22, 6:41 PM CST
Where
Carroll County, Coon Rapids
Measured
1.75 in hail
Property damage
$25,000
Crop damage
$5,000
Reported by
LAW ENFORCEMENT
Coordinates
41.617, -94.100

Hail, Guthrie

When
May 22, 6:41 PM CST
Where
Guthrie County, 10 mi W of Guthrie Center
Measured
3 in hail
Property damage
$15,000
Crop damage
$10,000
Reported by
TRAINED SPOTTER
Coordinates
41.000, -93.783

Tornado, Story

When
May 22, 6:45 PM CST
Where
Story County, 1 mi W of Maxwell
Rating
F0
Path length
1.4 mi
Path width
50 yd
Property damage
$2,000
Crop damage
$2,000
Reported by
AMATEUR RADIO
Coordinates
42.036, -93.465 (the zone’s center; the record gives no point)

Intermittent tornado track in open fields.

Tornado, Dallas

When
May 22, 6:45 PM CST
Where
Dallas County, 4 mi E of Dexter
Rating
F0
Path length
0.2 mi
Path width
25 yd
Reported by
AMATEUR RADIO
Coordinates
41.717, -93.033

Brief touchdown in open field.

Tornado, Dallas

When
May 22, 6:55 PM CST to 7:01 PM CST
Where
Dallas County, 4 mi W of Adel
Rating
F1
Path length
5 mi
Path width
100 yd
Property damage
$2,000
Crop damage
$5,000
Reported by
LAW ENFORCEMENT
Coordinates
41.617, -94.000

Tornado tracked through open fields for the most part. It also lifted from time to time.

Flash Flood, Story

When
May 22, 6:58 PM CST to 11:15 PM CST
Where
Story County, Countywide
Property damage
$250,000
Crop damage
$50,000
Reported by
LAW ENFORCEMENT
Coordinates
41.933, -93.100

Tornado, Jasper

When
May 22, 7:06 PM CST
Where
Jasper County, 1 mi NE of Newton
Rating
F0
Path length
0.2 mi
Path width
25 yd
Reported by
LAW ENFORCEMENT
Coordinates
41.933, -93.267

Bief tornado touchdown in fields northeast of Newton.

Tornado, Dallas

When
May 22, 7:13 PM CST
Where
Dallas County, 5 mi W of Waukee
Rating
F0
Path length
0.5 mi
Path width
50 yd
Property damage
$1,000
Crop damage
$5,000
Reported by
TRAINED SPOTTER
Coordinates
41.917, -92.917

Tornado touched down in fields west of Waukee.

Thunderstorm Wind, Marshall

When
May 22, 7:15 PM CST
Where
Marshall County, Melbourne
Measured
80 kt (92 mph) estimated gust
Property damage
$25,000
Reported by
AMATEUR RADIO
Coordinates
41.733, -93.050

Thunderstorm Wind, Marshall

When
May 22, 7:19 PM CST
Where
Marshall County, 4 mi W of Rhodes
Measured
69 kt (79 mph) estimated gust
Property damage
$10,000
Reported by
LAW ENFORCEMENT
Coordinates
41.567, -94.183

Tornado, Marshall

When
May 22, 7:19 PM CST to 7:20 PM CST
Where
Marshall County, 2 mi SW of Ferguson
Rating
F0
Path length
0.5 mi
Path width
40 yd
Crop damage
$1,000
Reported by
AMATEUR RADIO
Coordinates
41.800, -92.917

Tornado touched down in fields between Ferguson and Collins.

Tornado, Jasper

When
May 22, 7:20 PM CST
Where
Jasper County, 2 mi N of Newton
Rating
F0
Path length
0.2 mi
Path width
25 yd
Reported by
TRAINED SPOTTER
Coordinates
41.700, -94.000

Brief touchdown in open fields.

Thunderstorm Wind, Dallas

When
May 22, 7:22 PM CST
Where
Dallas County, 1 mi SE of Redfield
Measured
61 kt (70 mph) estimated gust
Property damage
$5,000
Reported by
LAW ENFORCEMENT
Coordinates
41.817, -92.983

Tornado, Jasper

When
May 22, 7:23 PM CST
Where
Jasper County, 10 mi NE of Newton
Rating
F0
Path length
0.2 mi
Path width
25 yd
Reported by
LAW ENFORCEMENT
Coordinates
41.686, -93.054 (the zone’s center; the record gives no point)

Brief touchdown in open fields.

Tornado, Dallas

When
May 22, 7:27 PM CST
Where
Dallas County, 2 mi NW of Dallas Center
Rating
F0
Path length
0.2 mi
Path width
25 yd
Reported by
LAW ENFORCEMENT
Coordinates
41.833, -93.150

Brief tornado touchdown in open fileds.

Tornado, Jasper

When
May 22, 7:35 PM CST
Where
Jasper County, 8 mi W of Newburg
Rating
F0
Path length
0.2 mi
Path width
25 yd
Reported by
LAW ENFORCEMENT
Coordinates
41.686, -93.054 (the zone’s center; the record gives no point)

Brief tornado touchdown in open fields.

Flash Flood, Dallas

When
May 22, 7:36 PM CST to May 23, 2:00 AM CST
Where
Dallas County, Countywide
Property damage
$250,000
Crop damage
$50,000
Reported by
LAW ENFORCEMENT
Coordinates
41.933, -93.100

Tornado, Jasper

When
May 22, 7:36 PM CST to 7:38 PM CST
Where
Jasper County, 2 mi N of Baxter
Rating
F0
Path length
1.5 mi
Path width
40 yd
Property damage
$5,000
Crop damage
$2,000
Reported by
AMATEUR RADIO
Coordinates
41.783, -94.533

Intermitttent track across open country.

Flash Flood, Polk

When
May 22, 7:39 PM CST to 11:15 PM CST
Where
Polk County, North Portion
Property damage
$100,000
Crop damage
$50,000
Reported by
EMERGENCY MANAGER
Coordinates
41.817, -93.650

Tornado, Marshall

When
May 22, 7:40 PM CST to 7:58 PM CST
Where
Marshall County, Melbourne
Rating
F1
Path length
17 mi
Path width
100 yd
Property damage
$10,000
Crop damage
$5,000
Reported by
LAW ENFORCEMENT
Coordinates
42.083, -92.683

Most of track of tornado was in open countryside. No real significant damage occurred.

Hail, Guthrie

When
May 22, 7:41 PM CST
Where
Guthrie County, Yale
Measured
1 in hail
Property damage
$3,000
Crop damage
$5,000
Reported by
TRAINED SPOTTER
Coordinates
41.684, -94.501 (the zone’s center; the record gives no point)

Lightning, Story

When
May 22, 8:00 PM CST
Where
Story County, Nevada
Injuries
2 direct, 0 indirect
Reported by
EMERGENCY MANAGER
Coordinates
41.900, -93.700

Tornado, Polk

When
May 22, 8:06 PM CST to 8:12 PM CST
Where
Polk County, 2 mi W of Alleman
Rating
F0
Path length
2 mi
Path width
50 yd
Reported by
BROADCAST MEDIA
Coordinates
42.000, -92.850

Intermittent touchdown in fields west of Alleman.

Tornado, Tama

When
May 22, 8:15 PM CST
Where
Tama County, 1 mi S of Garwin
Rating
F0
Path length
0.3 mi
Path width
30 yd
Crop damage
$1,000
Reported by
LAW ENFORCEMENT
Coordinates
42.080, -92.532 (the zone’s center; the record gives no point)

Touchdown in open fields south of Garwin.

Flash Flood, Marshall

When
May 22, 8:30 PM CST to 11:15 PM CST
Where
Marshall County, Countywide
Property damage
$250,000
Crop damage
$50,000
Reported by
LAW ENFORCEMENT
Coordinates
42.036, -92.999 (the zone’s center; the record gives no point)

Thunderstorm Wind, Marshall

When
May 22, 8:35 PM CST
Where
Marshall County, 3 mi W of Le Grand
Measured
61 kt (70 mph) estimated gust
Property damage
$10,000
Reported by
TRAINED SPOTTER
Coordinates
41.300, -95.083

Flash Flood, Boone

When
May 22, 8:36 PM CST to 11:15 PM CST
Where
Boone County, Countywide
Property damage
$200,000
Crop damage
$50,000
Reported by
LAW ENFORCEMENT
Coordinates
42.200, -92.467

Flash Flood, Audubon

When
May 22, 8:50 PM CST to 11:15 PM CST
Where
Audubon County, Countywide
Property damage
$150,000
Crop damage
$50,000
Reported by
LAW ENFORCEMENT
Coordinates
41.400, -95.167

Thunderstorm Wind, Tama

When
May 22, 8:50 PM CST
Where
Tama County, Garwin
Measured
57 kt (66 mph) estimated gust
Property damage
$10,000
Reported by
NEWSPAPER
Coordinates
41.900, -95.067

Thunderstorm Wind, Cass

When
May 22, 8:56 PM CST
Where
Cass County, Lewis
Measured
50 kt (58 mph) estimated gust
Property damage
$1,000
Reported by
TRAINED SPOTTER
Coordinates
42.233, -92.417

Hail, Tama

When
May 22, 9:06 PM CST
Where
Tama County, Traer
Measured
1.75 in hail
Property damage
$15,000
Crop damage
$5,000
Reported by
BROADCAST MEDIA
Coordinates
41.817, -93.617

Thunderstorm Wind, Cass

When
May 22, 9:08 PM CST
Where
Cass County, 8 mi W of Atlantic
Measured
54 kt (62 mph) estimated gust
Property damage
$5,000
Reported by
EMERGENCY MANAGER
Coordinates
41.300, -95.133

Hail, Tama

When
May 22, 9:12 PM CST
Where
Tama County, 4 mi NE of Traer
Measured
1 in hail
Property damage
$3,000
Crop damage
$5,000
Reported by
TRAINED SPOTTER
Coordinates
41.400, -95.017

Hail, Polk

When
May 22, 9:15 PM CST
Where
Polk County, Alleman
Measured
0.88 in hail
Property damage
$2,000
Crop damage
$5,000
Reported by
TRAINED SPOTTER
Coordinates
41.283, -94.883

Thunderstorm Wind, Cass

When
May 22, 9:30 PM CST
Where
Cass County, 3 mi W of Lewis
Measured
74 kt (85 mph) estimated gust
Property damage
$100,000
Crop damage
$2,000
Reported by
EMERGENCY MANAGER
Coordinates
41.317, -95.067

Thunderstorm Wind, Cass

When
May 22, 9:30 PM CST
Where
Cass County, Atlantic
Measured
69 kt (79 mph) estimated gust
Property damage
$15,000
Reported by
TRAINED SPOTTER
Coordinates
41.400, -95.017

Thunderstorm Wind, Cass

When
May 22, 9:39 PM CST
Where
Cass County, 1 mi N of Cumberland
Measured
52 kt (60 mph) estimated gust
Property damage
$2,000
Reported by
EMERGENCY MANAGER
Coordinates
41.400, -94.833

Thunderstorm Wind, Cass

When
May 22, 9:45 PM CST
Where
Cass County, 1 mi NE of Lewis
Measured
52 kt (60 mph) estimated gust
Property damage
$1,000
Reported by
EMERGENCY MANAGER
Coordinates
41.267, -94.917

Thunderstorm Wind, Cass

When
May 22, 9:50 PM CST
Where
Cass County, Atlantic
Measured
61 kt (70 mph) estimated gust
Property damage
$10,000
Reported by
TRAINED SPOTTER
Coordinates
41.450, -94.767

Hail, Cass

When
May 22, 9:57 PM CST
Where
Cass County, 5 mi SW of Anita
Measured
1 in hail
Property damage
$2,000
Crop damage
$5,000
Reported by
EMERGENCY MANAGER
Coordinates
41.433, -94.767

Thunderstorm Wind, Cass

When
May 22, 10:00 PM CST
Where
Cass County, 2 mi W of Cumberland
Measured
57 kt (66 mph) estimated gust
Property damage
$10,000
Reported by
TRAINED SPOTTER
Coordinates
41.300, -94.467

Thunderstorm Wind, Cass

When
May 22, 10:00 PM CST
Where
Cass County, Anita
Measured
69 kt (79 mph) estimated gust
Property damage
$50,000
Reported by
BROADCAST MEDIA
Coordinates
41.332, -94.928 (the zone’s center; the record gives no point)

Thunderstorm Wind, Adams

When
May 22, 10:00 PM CST to May 23, 10:00 PM CST
Where
Adams County, 5 mi W of Corning
Measured
65 kt (75 mph) estimated gust
Injuries
2 direct, 0 indirect
Property damage
$50,000
Reported by
EMERGENCY MANAGER
Coordinates
40.800, -94.733

Thunderstorm Wind, Adams

When
May 22, 10:00 PM CST
Where
Adams County, 9 mi N of Corning
Measured
69 kt (79 mph) estimated gust
Property damage
$50,000
Reported by
EMERGENCY MANAGER
Coordinates
41.029, -94.699 (the zone’s center; the record gives no point)

Thunderstorm Wind, Adams

When
May 22, 10:00 PM CST
Where
Adams County, 11 mi N of Corning
Measured
65 kt (75 mph) estimated gust
Property damage
$25,000
Reported by
EMERGENCY MANAGER
Coordinates
41.683, -94.450

Thunderstorm Wind, Taylor

When
May 22, 10:00 PM CST
Where
Taylor County, 5 mi W of Sharpsburg
Measured
65 kt (75 mph) estimated gust
Property damage
$50,000
Reported by
EMERGENCY MANAGER
Coordinates
41.517, -93.100

Thunderstorm Wind, Cass

When
May 22, 10:01 PM CST
Where
Cass County, 1 mi S of Anita
Measured
69 kt (79 mph) estimated gust
Property damage
$50,000
Reported by
EMERGENCY MANAGER
Coordinates
41.300, -94.467

Thunderstorm Wind, Adair

When
May 22, 10:05 PM CST
Where
Adair County, Greenfield
Measured
57 kt (66 mph) estimated gust
Property damage
$10,000
Reported by
EMERGENCY MANAGER
Coordinates
41.133, -94.633

Flash Flood, Black Hawk

When
May 22, 10:05 PM CST to May 23, 1:15 AM CST
Where
Black Hawk County, Waterloo
Property damage
$75,000
Reported by
EMERGENCY MANAGER
Coordinates
41.367, -94.367

Thunderstorm Wind, Adair

When
May 22, 10:12 PM CST
Where
Adair County, Greenfield
Measured
52 kt (60 mph) estimated gust
Property damage
$5,000
Reported by
EMERGENCY MANAGER
Coordinates
41.267, -94.017

Thunderstorm Wind, Adams

When
May 22, 10:13 PM CST
Where
Adams County, 7 mi N of Prescott
Measured
61 kt (70 mph) estimated gust
Property damage
$25,000
Reported by
LAW ENFORCEMENT
Coordinates
41.500, -94.650

Thunderstorm Wind, Guthrie

When
May 22, 10:20 PM CST
Where
Guthrie County, 3 mi E of Guthrie Center
Measured
61 kt (70 mph) estimated gust
Property damage
$15,000
Reported by
EMERGENCY MANAGER
Coordinates
41.933, -94.600

Thunderstorm Wind, Adair

When
May 22, 10:27 PM CST
Where
Adair County, 7 mi NE of Greenfield
Measured
53 kt (61 mph) estimated gust
Property damage
$5,000
Reported by
AMATEUR RADIO
Coordinates
40.717, -94.367

Thunderstorm Wind, Madison

When
May 22, 10:30 PM CST
Where
Madison County, 5 mi S of Winterset
Measured
87 kt (100 mph) estimated gust
Property damage
$75,000
Crop damage
$10,000
Reported by
LAW ENFORCEMENT
Coordinates
40.900, -94.550

Thunderstorm Wind, Clarke

When
May 22, 10:30 PM CST
Where
Clarke County, 2 mi S of Osceola
Measured
67 kt (77 mph) measured gust
Property damage
$10,000
Reported by
NEWSPAPER
Coordinates
42.000, -93.983

Tornado, Adair

When
May 22, 10:33 PM CST
Where
Adair County, Adair
Rating
F0
Path length
0.2 mi
Path width
30 yd
Reported by
LAW ENFORCEMENT
Coordinates
41.283, -93.867

Brief touchdown in open area near Adair.

Thunderstorm Wind, Ringgold

When
May 22, 10:37 PM CST
Where
Ringgold County, 7 mi W of Mt Ayr
Measured
65 kt (75 mph) estimated gust
Property damage
$10,000
Reported by
TRAINED SPOTTER
Coordinates
41.617, -94.017

Thunderstorm Wind, Taylor

When
May 22, 10:39 PM CST
Where
Taylor County, 1 mi N of Lenox
Measured
61 kt (70 mph) estimated gust
Property damage
$25,000
Reported by
EMERGENCY MANAGER
Coordinates
41.550, -93.783

Thunderstorm Wind, Madison

When
May 22, 10:45 PM CST
Where
Madison County, 3 mi W of St Charles
Measured
92 kt (106 mph) measured gust
Property damage
$40,000
Crop damage
$10,000
Reported by
TRAINED SPOTTER
Coordinates
41.417, -93.650

Thunderstorm Wind, Dallas

When
May 22, 10:47 PM CST
Where
Dallas County, Adel
Measured
52 kt (60 mph) estimated gust
Property damage
$5,000
Reported by
EMERGENCY MANAGER
Coordinates
41.350, -93.800

Thunderstorm Wind, Polk

When
May 22, 10:50 PM CST
Where
Polk County, 6 mi S of Clive
Measured
57 kt (66 mph) estimated gust
Property damage
$5,000
Reported by
BROADCAST MEDIA
Coordinates
41.250, -94.783

Thunderstorm Wind, Warren

When
May 22, 11:01 PM CST
Where
Warren County, 1 mi ENE of Spring Hill
Measured
61 kt (70 mph) estimated gust
Property damage
$5,000
Reported by
AMATEUR RADIO
Coordinates
41.517, -93.100

Tornado, Warren

When
May 22, 11:02 PM CST to 11:11 PM CST
Where
Warren County, 1 mi S of Bevington
Rating
F1
Path length
7 mi
Path width
250 yd
Property damage
$100,000
Crop damage
$5,000
Reported by
FIRE DEPT/RESCUE SQUAD
Coordinates
41.417, -93.017

Tornado spun up in a well organized bow echo and tracked across northern Warren County.

Thunderstorm Wind, Cass

When
May 22, 11:15 PM CST
Where
Cass County, Massena
Measured
61 kt (70 mph) estimated gust
Property damage
$10,000
Reported by
TRAINED SPOTTER
Coordinates
41.332, -94.928 (the zone’s center; the record gives no point)

Thunderstorm Wind, Jasper

When
May 22, 11:20 PM CST
Where
Jasper County, Monroe
Measured
61 kt (70 mph) estimated gust
Property damage
$25,000
Crop damage
$1,000
Reported by
FIRE DEPT/RESCUE SQUAD
Coordinates
41.917, -94.683

Thunderstorm Wind, Jasper

When
May 22, 11:25 PM CST
Where
Jasper County, Monroe
Measured
61 kt (70 mph) estimated gust
Property damage
$10,000
Reported by
BROADCAST MEDIA
Coordinates
40.983, -94.833

Thunderstorm Wind, Jasper

When
May 22, 11:30 PM CST
Where
Jasper County, 2 mi SE of Reasnor
Measured
65 kt (75 mph) estimated gust
Property damage
$10,000
Reported by
TRAINED SPOTTER
Coordinates
42.100, -92.683

Thunderstorm Wind, Jasper

When
May 22, 11:30 PM CST
Where
Jasper County, 2 mi E of Reasnor
Measured
61 kt (70 mph) estimated gust
Property damage
$5,000
Reported by
TRAINED SPOTTER
Coordinates
41.600, -94.533

Thunderstorm Wind, Marion

When
May 22, 11:50 PM CST
Where
Marion County, 4 mi W of Pella
Measured
61 kt (70 mph) estimated gust
Property damage
$25,000
Reported by
EMERGENCY MANAGER
Coordinates
41.117, -94.733

Flash Flood, Webster

When
May 23, 2:00 AM CST to 5:00 AM CST
Where
Webster County, Ft Dodge
Measured
50
Property damage
$5,000
Reported by
TRAINED SPOTTER
Coordinates
41.150, -94.733

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.
Lightning
A lightning strike that killed, injured or caused damage.

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

The same day elsewhere

More

Every storm in Iowa in 2004Every state in 2004This day in weather historyThe tornado archive for Iowa, 2004Warnings 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: 5394340, 5394341, 5394342, 5394395, 5394396, 5394397, 5394398, 5394399, 5394400, 5394401, 5394402, 5394403, 5394404, 5394405, 5394406, 5394407, 5394739, 5394408, 5394740, 5394409, 5394410, 5394738, 5394741, 5394411, 5394412, 5394413, 5394742, 5394743, 5394750, 5394744, 5394414, 5394415, 5394745, 5394416, 5394417, 5394418, 5394419, 5394420, 5394527, 5394528, and more.