Tornadoes · United States · Iowa · 2008

EF0 tornado, Dickens to Webb, Iowa, June 11, 2008

From Dickens to Webb, this EF0 tornado ran 0.4 miles across Clay County on June 11, 2008, touching down at 7:11 PM CDT and reaching 50 yards wide. It killed nobody.

The rating scale

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

  1. EF065 to 85 mphthis tornado

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

  2. EF186 to 110 mph

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

  3. EF2111 to 135 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. EF3136 to 165 mph

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

  5. EF4166 to 200 mph

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

  6. EF5over 200 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
EF0
Date
June 11, 2008
Touchdown
7:11 PM CDT (00:11 UTC)
Lifted
7:12 PM CDT (00:12 UTC)
On the ground
1 minutes
Path length
0.4 miles (0.7 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Clay County
Touchdown point
43.160, -95.020
Lift-off point
43.165, -95.015
Record number
0806111811-02

What the Weather Service recorded

Thunderstorms produced several tornadoes, along with large hail, damaging winds, and flash flooding in northwest Iowa during the late afternoon and early evening of June 11th.

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

23 minutes of warning. NWS FSD issued a tornado warning for this county at 23:48 UTC, 23 minutes before the tornado touched down, in force until 00:30 UTC.

The county was under a tornado watch, issued at 19:54 UTC and running to 01:50 UTC.

Issued (UTC)ExpiredProductOffice
10:16 UTC15:09 UTCSevere Thunderstorm WatchFSD
13:00 UTC06:49 UTCFlash Flood WatchFSD
16:00 UTC20:06 UTCWind AdvisoryFSD
19:54 UTC01:50 UTCTornado WatchFSD
23:28 UTC00:00 UTCTornado WarningFSD
23:48 UTC00:30 UTCTornado WarningFSD
00:20 UTC00:45 UTCTornado 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 Moderate Risk, with a 0.15 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 19:58 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.

Minneapolis, MN (KMPX), 00:00Z

0.2 hours before the tornado, 219 km from the path. June 12, 2008.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2008-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 47 joules per kilogram, CIN -333, lifted condensation level 523 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, Minneapolis, MN at 00:00Z on 2008-06-12The 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 574 square meters per square second, 0 to 6 km bulk shear 56 knots.19395878Sfc1 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
47 J/kg
Mixed-layer CIN
-333 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
523 m above ground
0-6 km bulk shear
56 kt
0-1 km bulk shear
40 kt
0-1 km storm-relative helicity
574 m²/s²
0-3 km storm-relative helicity
740 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0
0-3 km lapse rate
3.9 K/km

Open this sounding in Storm Lab

Minneapolis, MN (KMPX), 12:00Z

11.8 hours after it, 219 km from the path. June 12, 2008.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 2008-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -84111, lifted condensation level 965 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Minneapolis, MN at 12:00Z on 2008-06-12The 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 54 square meters per square second, 0 to 6 km bulk shear 80 knots.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
-84111 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
965 m above ground
0-6 km bulk shear
80 kt
0-1 km bulk shear
10 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
228 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.2 K/km

Open this sounding in Storm Lab

The surface observations

Spencer (SPW), 16 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
22:53 UTC7769170° 14 kt231000.7
23:16 UTC7769.8180° 8 kt1001VCTS
23:38 UTC75.269.8160° 11 kt1002+TSRA
23:49 UTC73.471.6150° 19 kt1001.4TSRA BR
23:53 UTC7571200° 25 kt361002.4+TSRA BR
23:58 UTC71.664.4220° 11 kt361000.7+TSRA
00:04 UTC71.666.2200° 16 kt191001.7-TSRA
00:32 UTC69.864.4210° 22 kt291002.7-TSRA
00:53 UTC6965290° 10 kt211002.4
01:12 UTC6864.4320° 7 kt1002.7
01:24 UTC6862.6310° 7 kt1003.7
01:53 UTC6763310° 8 kt1003.7-RA

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

The radar

The Sioux Falls radar (KFSD), 146 km away, was scanning. The volume nearest the touchdown began at 00:11 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
22:50 UTCTORNADO 01 E PaullinaO'Brien, IATORNADO TOUCHDOWN
23:11 UTCHAIL 0.88PrimgharO'Brien, IA
23:15 UTCTORNADO 05 Nw SutherlandO'Brien, IAPOWER LINES DOWN...WIDESPREAD DEBRIS...MACHINE SHED DOWN
23:20 UTCTORNADO 04 Sw SutherlandO'Brien, IAHOOP BARN DAMAGED
23:55 UTCTORNADO3 Sw SpencerClay, IAEXTENSIVE DAMAGE TO FARM...POWER LINES DOWN
00:11 UTCTORNADO2 N DickensClay, IAPOLE BARN DOWN
00:25 UTCTORNADO2 Nne WebbClay, IARAIN WRAPPED
00:30 UTCFLASH FLOODStorm LakeBuena Vista, IASTREET FLOODING STARTED AT 730 PM AND IMPROVED AROUND 930 PM WITH SOME CARS STALLING IN THE WATER
00:30 UTCTSTM WND GST 03 E RembrandtBuena Vista, IA55 TO 60 MPH WITH BRANCHES DOWN
00:30 UTCTSTM WND GST 603 E RembrandtBuena Vista, IA55 TO 50 MPH WINDS WITH BRANCHES DOWN
00:43 UTCTSTM WND DMG1 Ssw WallingfordEmmet, IA16 TO 18 INCH DIAMETER TREE DOWN.
00:43 UTCTSTM WND DMG2 S WallingfordEmmet, IAPOSSIBLE TORNADO DAMAGE. 2 OUT-BUILDINGS DESTROYED.
01:18 UTCHEAVY RAIN 0LaurensPocahontas, IA1.5 TO 2 INCHES OF RAIN.
01:27 UTCTSTM WND DMG4 Ese ArmstrongKossuth, IA1 1/2 FOOT DIAMTER ASH TREE DOWN.
01:43 UTCTORNADO 04 Sw SutherlandO'Brien, IAHOOP BARN DAMAGED
02:00 UTCFLASH FLOOD1 S MallardPalo Alto, IAWATER REPORTED TO BE OVER HIGHWAY 4 SOUTH OF MALLARD.
02:03 UTCHEAVY RAIN 1.464 E ArmstrongKossuth, IA

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

This ground now

The live radar over the trackEvery 2008 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

The other tornadoes of June 11, 2008

41 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 115:51 AM CDTEF1Marshall, SD0.320
June 115:25 PM CDTEF0Lyon, IA0.850
June 115:29 PM CDTEF0Osceola, IA0.850
June 115:37 PM CDTEF0Woodbury, IA0.950
June 115:46 PM CDTEF1Nobles, MN3.8100$70,000
June 115:49 PM CDTEF0O'Brien, IA0.950
June 116:05 PM CDTEF1Murray, MN2.71001$100,000
June 116:06 PM CDTEF2O'Brien, IA5.7300$200,000
June 116:13 PM CDTEF0Barton, KS0.750
June 116:20 PM CDTEF1O'Brien, IA0.950$5,000
June 116:25 PM CDTEF1Burt, NE1.3440
June 116:27 PM CDTEF3Harrison, IA13.0440448
June 116:40 PM CDTEF2Clay, IA13.1100$300,000
June 116:45 PM CDTEF0Cottonwood, MN2.050$5,000
June 116:45 PM CDTEF1Barton, KS10.0100$65,000
June 116:59 PM CDTEF0Douglas, NE0.140
June 117:11 PM CDTEF0Ellsworth, KS0.750
June 117:20 PM CDTEF1Brown, MN0.625$300,000
June 117:20 PM CDTEF1Pottawattamie, IA2.440
June 117:20 PM CDTEF0Monona, IA0.360
June 117:21 PM CDTEF0Crawford, IA1.260
June 117:23 PM CDTEF0Pottawattamie, IA0.820
June 117:25 PM CDTEF0Clay, IA0.450
June 117:35 PM CDTEF0Barton, KS0.750
June 117:39 PM CDTEF0Cass, NE0.240
June 117:46 PM CDTEF0Brown, MN0.425$100,000
June 117:50 PM CDTEF1Cass, NE5.480
June 117:52 PM CDTEF1Brown, MN2.025$100,000
June 117:57 PM CDTEF0Barton, KS0.750
June 117:59 PM CDTEF0Shelby, IA0.460
June 118:05 PM CDTEF0Shelby, IA0.280
June 118:15 PM CDTEF0Ellsworth, KS0.850$10,000
June 118:38 PM CDTEF0Jefferson, NE0.240
June 118:48 PM CDTEF0Saline, KS1.675
June 119:06 PM CDTEF0Sibley, MN0.325
June 119:40 PM CDTEF3Saline, KS16.4225$2.6 million
June 1110:12 PM CDTEF3Dickinson, KS15.388013$20 million
June 1110:45 PM CDTEF0Dickinson, KS0.250
June 1110:48 PM CDTEF4Manhattan tornado, KS8.6440$66 million
June 1111:20 PM CDTEF0Pottawatomie, KS4.675
June 1111:46 PM CDTEF2Pottawatomie, KS17.33002

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.