Tornadoes · United States · Iowa · 2004

F0 tornado, Tama County, Iowa, May 22, 2004

This F0 tornado ran 0.3 miles across Tama County on May 22, 2004, touching down at 9:15 PM CDT and reaching 30 yards wide. It killed nobody.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. F040 to 72 mphthis tornado

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F173 to 112 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 mph

    Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

  4. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 mph

    Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

  7. Unrated

    The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

The record

Rating
F0
Date
May 22, 2004
Touchdown
9:15 PM CDT (02:15 UTC)
Path length
0.3 miles (0.5 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
County
Tama County
Touchdown point
42.080, -92.680
Lift-off point
42.080, -92.680
Record number
921

The warnings

34 minutes of warning. NWS DMX issued a tornado warning for this county at 01:41 UTC, 34 minutes before the tornado touched down, in force until 02:30 UTC.

Issued (UTC)ExpiredProductOffice
01:41 UTC02:30 UTCTornado WarningDMX
02:27 UTC03:30 UTCTornado WarningDMX
02:31 UTC17:15 UTCFlash Flood WarningDMX

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The forecast that day

The Storm Prediction Center had this point in a Moderate Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 20:01 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The surface observations

Marshalltown (MIW), 20 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
00:53 UTC696670° 16 kt1002.4VCTS
01:53 UTC6766190° 15 kt251004.7+TSRA BR
02:53 UTC656460° 22 kt1001.4-TSRA
03:53 UTC6261300° 8 kt1002.7TSRA BR

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Des Moines radar (KDMX), 95 km away, was scanning. The volume nearest the touchdown began at 02:16 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
01:06 UTCTORNADONe NewtonJasper, IATORNADO BRIEF TOUCHDOWN
01:15 UTCTSTM WND GST 92MelbourneMarshall, IA92 MPH WINDS MEASURED BETWEEN COLLINS AND MELBOURNE
01:19 UTCTSTM WND GST 80CollinsStory, IA80 MPH WINDS BETWEEN COLLINS AND RHODES
01:19 UTCTORNADOFergusonMarshall, IAREPORTED BY AMATEUR RADIO OPERATOR.
01:20 UTCTORNADO2 N NewtonJasper, IABRIEF TOUCHDOWN.
01:20 UTCTORNADOLaurelMarshall, IATORNADO 4 MI FROM LAUREL
01:23 UTCTORNADO10 Ne NewtonJasper, IATORNADO ON GROUND 10 MI NE OF NEWTON
01:35 UTCTORNADO4 S LaurelJasper, IATORNADO TOUCHDOWN
01:36 UTCTORNADO3 N BaxterMarshall, IAS62 HIGHWAY AT COUNTY LINE
01:38 UTCTORNADO1 N BaxterJasper, IA
01:40 UTCTORNADOMelbourneMarshall, IATORNADO DOWN
01:49 UTCTORNADOHaverhillMarshall, IA
01:58 UTCTORNADO1 S Le GrandMarshall, IATORNADO DOWN 1 MI SOUTH OF LE GRAND
02:15 UTCTORNADO1 S GarwinTama, IATORNADO DOWN 1 MI SO OF GARWIN
02:30 UTCFLASH FLOODMarshalltownMarshall, IAMOST OF TOWN OF MARSHALLTOWN IS FLOODED.
02:30 UTCTORNADO1 S GarwinTama, IATORNADO ON THE GROUND 1 MI SOUTH OF GARWIN
02:35 UTCTSTM WND DMG3 W Le GrandMarshall, IA2 AND 3 FOOT DIAMETER TREES ON HOMES 3 MI WEST OF LE GRAND OFF HIGHWAY 30.
03:06 UTCHAIL 1.75TraerTama, IATV9 SPOTTER REPORTS GOLF BALL SIZED HAIL AND FLOODING EAST SIDE OF TRAER NEAR HIGHWAY 8.
03:12 UTCHAIL 14 Ne TraerTama, IAQUARTER SIZED HAIL 4 MILES NE OF TRAER
04:05 UTCFLASH FLOODWaterlooBlack Hawk, IAEXTENSIVE STREET FLOODING AT LEAST CURB HIGH...DEEPER IN SOME LOCATIONS.
04:20 UTCFLASH FLOODWaterlooBlack Hawk, IAKNEE HIGH WATER ON FRANKLIN AVENUE.
04:20 UTCHEAVY RAIN 3.25EvansdaleBlack Hawk, IA3.25 INCHES OF RAIN SINCE 10 PM.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2004 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

The other tornadoes of May 22, 2004

64 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 223:58 PM EDTF0Saginaw, MI2.550
May 224:02 PM EDTF0Saginaw, MI0.230
May 222:10 PM MDTF0Goshen, WY0.225
May 224:35 PM EDTF0Shiawassee, MI0.120
May 224:45 PM EDTF1Tuscola, MI1.050$10,000
May 225:10 PM EDTF0Sanilac, MI1.050$20,000
May 223:20 PM MDTF0Logan, CO0.150
May 225:22 PM CDTF0McPherson, NE0.220
May 225:28 PM CDTF0Furnas, NE0.150$10,000
May 225:35 PM CDTF1Furnas, NE3.0400$300,000
May 225:40 PM CDTF0Logan, NE0.110
May 225:40 PM CDTF0Logan, NE2.020
May 225:49 PM CDTF0Harlan, NE0.250$150,000
May 226:04 PM CDTF0Harlan, NE0.2100
May 226:10 PM CDTF0Colfax, NE0.550
May 226:11 PM CDTF0Harlan, NE0.275
May 226:34 PM CDTF1Custer, NE0.220$40,000
May 226:36 PM CDTF0Franklin, NE0.150$10,000
May 226:46 PM CDTF0Webster, NE3.5125$250,000
May 226:50 PM CDTF1Custer, NE0.530$50,000
May 226:53 PM CDTF0Thayer, NE0.275
May 227:00 PM CDTF2Thayer, NE8.0800$2.5 million
May 227:07 PM CDTF1Adair, IA7.1100$50,000
May 227:10 PM CDTF1Adams, NE7.0150$1.0 million
May 227:11 PM CDTF0Madison, IA0.330
May 227:12 PM CDTF0Custer, NE0.210
May 227:13 PM CDTF0Lincoln, NE0.110
May 227:15 PM CDTF1Dodge, NE2.0200
May 227:17 PM CDTF0Custer, NE0.110
May 227:19 PM CDTF2Adams, NE23.0700$5.0 million
May 227:24 PM CDTF0Thayer, NE1.050
May 227:26 PM CDTF1Fillmore, NE2.5100$100,000
May 227:29 PM CDTF1Clay, NE0.225
May 227:30 PM CDTF4Hallam tornado, NE54.04,400138$160 million
May 227:32 PM CDTF1Fillmore, NE2.0150$100,000
May 227:34 PM CDTF0York, NE0.275$40,000
May 227:35 PM CDTF0Jefferson, NE2.080
May 227:45 PM CDTF0Story, IA1.450$2,000
May 227:45 PM CDTF0Dallas, IA0.225
May 227:55 PM CDTF1Dallas, IA5.0100$2,000
May 228:06 PM CDTF0Jasper, IA0.225
May 228:13 PM CDTF0Dallas, IA0.550$1,000
May 228:19 PM CDTF0Harrison, IA0.260
May 228:19 PM CDTF0Marshall, IA0.540
May 228:20 PM CDTF0Jasper, IA0.225
May 228:23 PM CDTF0Jasper, IA0.225
May 228:27 PM CDTF0Dallas, IA0.225
May 228:35 PM CDTF0Jasper, IA0.225
May 228:36 PM CDTF0Jasper, IA1.540$10,000
May 228:40 PM CDTF1Marshall, IA17.0100$10,000
May 228:42 PM CDTF0Republic, KS0.150$10,000
May 228:44 PM CDTF2Republic, KS2.0100$90,000
May 228:45 PM CDTF0Shelby, IA2.0200
May 228:53 PM CDTF1Thayer, NE10.0400$1.0 million
May 228:56 PM CDTF0Republic, KS0.150
May 228:59 PM CDTF0Republic, KS0.150
May 229:06 PM CDTF0Polk, IA2.050
May 229:25 PM CDTF0Thayer, NE6.0200$250,000
May 229:30 PM CDTF1Jefferson, NE3.0100
May 229:40 PM CDTF1Cass, NE1.5150

All 65 of them

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.