Tornadoes · United States · Iowa · 2005

F0 tornado, Chatsworth to Ireton, Iowa, June 4, 2005

From Chatsworth to Ireton, this F0 tornado ran 0.1 miles across Sioux County on June 4, 2005, touching down at 10:22 PM CDT and reaching 50 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
June 4, 2005
Touchdown
10:22 PM CDT (03:22 UTC)
Path length
0.1 miles (0.2 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Sioux County
Touchdown point
42.970, -96.400
Lift-off point
42.970, -96.400
Record number
221

What the Weather Service recorded

A brief tornado caused no reported damage.

A brief tornado caused no reported damage.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

Issued (UTC)ExpiredProductOffice
02:49 UTC03:18 UTCTornado WarningFSD
03:14 UTC04:00 UTCSevere Thunderstorm WarningFSD
03:24 UTC04:12 UTCTornado WarningFSD
04:55 UTC08:00 UTCFlash Flood WarningFSD
05:02 UTC05:31 UTCSevere Thunderstorm WarningFSD

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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 00:55 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 air that afternoon

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Omaha, NE (KOAX), 00:00Z

3.4 hours before the tornado, 183 km from the path. June 5, 2005.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 2005-06-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1467 joules per kilogram, CIN -1, lifted condensation level 1297 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Omaha, NE at 00:00Z on 2005-06-05The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 21 square meters per square second, 0 to 6 km bulk shear 43 knots.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
1467 J/kg
Mixed-layer CIN
-1 J/kg
Surface CAPE
2360 J/kg
Mixed-layer LCL
1297 m above ground
0-6 km bulk shear
43 kt
0-1 km bulk shear
6 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
156 m²/s²
Significant tornado parameter
0.6
Supercell composite
6.1
0-3 km lapse rate
7.0 K/km

Open this sounding in Storm Lab

Omaha, NE (KOAX), 12:00Z

8.6 hours after it, 183 km from the path. June 5, 2005.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 12:00Z on 2005-06-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 7 joules per kilogram, CIN -262, lifted condensation level 840 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Omaha, NE at 12:00Z on 2005-06-05The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 11 square meters per square second, 0 to 6 km bulk shear 34 knots.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
7 J/kg
Mixed-layer CIN
-262 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
840 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
33 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.8 K/km

Open this sounding in Storm Lab

The surface observations

Le Mars (LRJ), 27 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
01:35 UTC69.866.20° 0 kt1001.4
01:40 UTC71680° 0 kt1001.4
01:55 UTC69.864.470° 3 kt1000.7
02:00 UTC70660° 0 kt1001.4
02:15 UTC69.866.2360° 3 kt1000.7
02:20 UTC71670° 0 kt1000.7
02:35 UTC69.866.2110° 3 kt1000.3
02:40 UTC71670° 0 kt1000.3
02:55 UTC71.666.2100° 4 kt1000.7
03:00 UTC72670° 0 kt1000.7
03:15 UTC71.666.2110° 4 kt1001.4
03:20 UTC726790° 4 kt1001.4
03:35 UTC69.866.2120° 3 kt1001.7
03:40 UTC7167110° 3 kt1001.7
03:55 UTC69.864.4130° 4 kt1001-RA
04:00 UTC7166110° 3 kt1001
04:15 UTC69.864.40° 0 kt1000.3
04:20 UTC70660° 0 kt1000.7
04:35 UTC6864.4140° 4 kt1000
04:40 UTC69650° 0 kt1000
04:55 UTC69.864.4160° 9 kt1000.3
05:00 UTC7065170° 6 kt1000.7
05:15 UTC6864.4170° 5 kt1000.3
05:20 UTC7065160° 7 kt1000

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

The radar

The Sioux Falls radar (KFSD), 74 km away, was scanning. The volume nearest the touchdown began at 03:23 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.

This ground now

The live radar over the trackEvery 2005 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

The other tornadoes of June 4, 2005

43 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 41:18 AM CDTF0Chautauqua, KS0.5110
June 41:43 AM CDTF0Montgomery, KS0.5110
June 46:35 AM CDTF0Cass, MO0.550
June 46:50 AM CDTF1Johnson, MO8.0752$1.1 million
June 412:30 PM MDTF0Keith, NE4.025
June 42:54 PM CDTF0Waushara, WI0.275
June 43:05 PM CDTF0Waushara, WI0.150
June 43:30 PM CDTF0McPherson, NE0.125
June 44:15 PM CDTF0McPherson, NE0.125
June 44:18 PM CDTF2Brown, KS3.0100$400,000
June 44:27 PM CDTF1Clark, WI17.050$600,000
June 44:27 PM CDTF0Marathon, WI1.275
June 44:39 PM CDTF0Marathon, WI1.3100
June 45:17 PM CDTF0Taylor, WI0.220$30,000
June 45:30 PM CDTF1Pottawatomie, KS0.5100$250,000
June 45:32 PM CDTF0Andrew, MO1.050
June 46:06 PM CDTF0Marathon, WI0.125
June 46:07 PM CDTF0Comanche, OK3.5150
June 46:20 PM CDTF0Marathon, WI0.125
June 46:45 PM CDTF0Stephens, OK0.120
June 46:48 PM CDTF1Gentry, MO0.5100
June 46:50 PM CDTF1Worth, MO15.0100$180,000
June 46:53 PM CDTF0Stephens, OK0.120
June 46:57 PM CDTF0Cowley, KS0.555
June 47:05 PM CDTF0Stephens, OK0.275$1,000
June 47:05 PM CDTF0Cowley, KS3.055
June 47:06 PM CDTF0Gentry, MO1.050
June 47:10 PM CDTF1Harrison, MO5.0100
June 47:13 PM CDTF0Osage, OK1.075$50,000
June 47:15 PM CDTF1Ringgold, IA1.050
June 47:38 PM CDTF0Archer, TX0.230
June 47:40 PM CDTF0Gentry, MO0.550
June 47:44 PM CDTF0Doniphan, KS1.050
June 47:46 PM CDTF0Buchanan, MO7.550$300,000
June 47:53 PM CDTF0Andrew, MO3.050
June 48:02 PM CDTF0Greenwood, KS0.5110
June 48:18 PM CDTF0Marathon, WI0.125
June 48:27 PM CDTF0Taylor, WI0.325$10,000
June 47:28 PM MDTF0Jefferson, ID0.230$10,000
June 48:54 PM CDTF0Daviess, MO0.550
June 49:45 PM CDTF0Union, SD0.150
June 49:50 PM CDTF0Plymouth, IA1.050
June 410:02 PM CDTF0Sioux, IA0.150

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.