Tornadoes · United States · Iowa · 2011

EF0 tornado, Brainard, Iowa, May 22, 2011

This EF0 tornado ran 1.4 miles across Fayette County on May 22, 2011, touching down at 4:01 PM CDT and reaching 50 yards wide. It killed nobody, and did $10,000 of property damage.

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
May 22, 2011
Touchdown
4:01 PM CDT (21:01 UTC)
Lifted
4:03 PM CDT (21:03 UTC)
On the ground
2 minutes
Path length
1.4 miles (2.2 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Property damage
$10,000
County
Fayette County
Touchdown point
42.963, -91.732
Lift-off point
42.966, -91.705
Record number
1105221501-01

What the Weather Service recorded

During the afternoon of May 22nd, severe thunderstorms developed along a cold front as it moved through northeast Iowa. These severe thunderstorms produced three confirmed tornadoes. The first tornado occurred in Howard County and was rated an EF2. The second (EF1) and third (EF0) tornadoes both occurred in Fayette County. Significant damage occurred between Chester (Howard County) and Lime Springs (Howard County) where several farms had buildings completely destroyed or significantly damaged. Three minor injuries occurred with the Howard County tornado. Around 850 customers were without power after the storms moved through in Howard County. Damages were estimated to be almost $700 thousand.

This was the second tornado to affect Fayette County. It was only in the ground for a couple of minutes as it crossed over County Road B64 between West Union and Elgin. For the short time the tornado was on the ground, it caused some roofing damage to a home and barn and snapped off several trees.

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.

The county was under a tornado watch, issued at 17:10 UTC and running to 22:30 UTC.

Issued (UTC)ExpiredProductOffice
17:10 UTC22:30 UTCTornado WatchARX
20:22 UTC21:00 UTCTornado WarningARX
21:19 UTC21:39 UTCSevere Thunderstorm WarningARX

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 20:00 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.

Davenport, (KDVN), 12:00Z

9.0 hours before the tornado, 180 km from the path. May 22, 2011.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2011-05-22Temperature 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 -72224, lifted condensation level 1775 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Davenport, at 12:00Z on 2011-05-22The 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 233 square meters per square second, 0 to 6 km bulk shear 40 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
0 J/kg
Mixed-layer CIN
-72224 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1775 m above ground
0-6 km bulk shear
40 kt
0-1 km bulk shear
34 kt
0-1 km storm-relative helicity
233 m²/s²
0-3 km storm-relative helicity
287 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.3 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 00:00Z

3.0 hours after it, 180 km from the path. May 23, 2011.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2011-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1935 joules per kilogram, CIN -18, lifted condensation level 935 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Davenport, at 00:00Z on 2011-05-23The 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 271 square meters per square second, 0 to 6 km bulk shear 46 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
1935 J/kg
Mixed-layer CIN
-18 J/kg
Surface CAPE
867 J/kg
Mixed-layer LCL
935 m above ground
0-6 km bulk shear
46 kt
0-1 km bulk shear
43 kt
0-1 km storm-relative helicity
271 m²/s²
0-3 km storm-relative helicity
364 m²/s²
Significant tornado parameter
3.4
Supercell composite
19.9
0-3 km lapse rate
5.3 K/km

Open this sounding in Storm Lab

The surface observations

Decorah (DEH), 35 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:15 UTC75.262.6180° 15 kt271000
19:35 UTC75.262.6170° 16 kt25999.3
19:55 UTC78.862.6170° 14 kt23998.6
20:15 UTC7762.6170° 15 kt30997.6
20:35 UTC78.862.6180° 17 kt28997.6
20:55 UTC75.264.4180° 20 kt31997.3-RA
21:15 UTC75.257.2190° 12 kt24998.3-DZ
21:35 UTC73.457.2200° 8 kt18999.3
21:55 UTC71.657.2210° 4 kt999
22:15 UTC73.457.2240° 5 kt999
22:35 UTC75.253.6270° 13 kt20999.3
22:55 UTC75.251.8240° 12 kt22999.3

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

The radar

The La Crosse radar (KARX), 104 km away, was scanning. The volume nearest the touchdown began at 21:01 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
19:50 UTCHAIL 1TripoliBremer, IA
20:13 UTCFUNNEL CLOUD2 Se TripoliBremer, IAFUNNEL CLOUD REACHED ABOUT 3/4 OF THE WAY TO THE GROUND BEFORE RETREATING INTO THE WALL CLOUD.
20:15 UTCHAIL 1TripoliBremer, IA
20:25 UTCFUNNEL CLOUD4 N OelweinFayette, IAPEA-SIZED HAIL AS WELL.
20:25 UTCHAIL 2SumnerBremer, IAUTILITY WORKERS REPORT. EAST SIDE OF SUMNER.
20:26 UTCHAIL 12 W SumnerBremer, IA
20:37 UTCTORNADORandaliaFayette, IASTORM SURVEY CONDUCTED 5/24. TORNADO BEGAN 3 MILES EAST OF SUMNER...ABOUT A HALF MILE NORTH OF INTERSECTION OF HWY 93 AND U AVENUE. CONTINUED EAST NORTHEAST FOR ABOUT 8 MILES...PASSING JUST NORTH OF RANDALIA AND ENDING 2
20:47 UTCTORNADO4 Wnw MaynardFayette, IAEM REPORTS POSSIBLE TORNADO TRACK WITH DOWNED TREES AND DAMAGED FARMS.
21:01 UTCHAIL 2West UnionFayette, IADELAYED REPORT
21:01 UTCTORNADO5 E West UnionFayette, IASTORM SURVEY CONDUCTED 5/24. TORNADO TOUCHED DOWN 5 MILES EAST OF WEST UNION NEAR INTERSECTION OF HWY B64 AND G AVENUE. PATH CONTINUED EAST NORTHEAST FOR ABOUT 1 MILE BEFORE LIFTING 2 MILES SOUTHWEST OF CLERMONT AT 403 P
21:05 UTCHAIL 0.5FayetteFayette, IA
21:17 UTCHAIL 1.5ElginFayette, IA
21:42 UTCFUNNEL CLOUDWadenaFayette, IA
21:53 UTCHAIL 1.753 Ese BrainardFayette, IA

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

This ground now

The live radar over the trackEvery 2011 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

The other tornadoes of May 22, 2011

47 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 222:13 PM CDTEF1Hennepin, MN13.6880148$167 million
May 222:33 PM CDTEF1Price, WI to IA, MN3.3600$4,000
May 222:33 PM CDTEF2Howard, IA to MN28.72503$775,000
May 222:38 PM CDTEF0Lafayette, MO0.340$500
May 222:40 PM CDTEF2Iowa, IA3.975$250,000
May 222:52 PM CDTEF0Anoka, MN0.230$50,000
May 222:54 PM CDTEF0Iowa, IA2.025$10,000
May 223:13 PM CDTEF0Bremer, IA0.130
May 223:16 PM CDTEF0Washington, MN2.675$50,000
May 223:25 PM CDTEF0Lafayette, MO0.150
May 223:37 PM CDTEF1Fayette, IA7.970$175,000
May 223:58 PM CDTEF0Lafayette, MO0.150$3,000
May 224:00 PM CDTEF1Barron, WI2.0300$200,000
May 224:05 PM CDTEF2Houston, MN to WI13.8150$15 million
May 224:10 PM CDTEF0Labette, KS0.350
May 224:37 PM CDTEF1Jasper, IN0.333$25,000
May 224:47 PM CDTEF1La Crosse, WI8.2125$920,000
May 224:50 PM CDTEF1Saline, MO3.575$230,000
May 225:15 PM CDTEF2Monroe, WI64.58001$7.7 million
May 225:34 PM CDTEF5Joplin tornado, MO21.61,6001581150$2.8 billion
May 225:39 PM CDTEF0Price, WI1.1350$1,000
May 225:52 PM CDTEF0Price, WI1.1400
May 226:01 PM CDTEF0Price, WI2.1350$5,000
May 226:10 PM CDTEF2Newton, MO14.1800$1.0 million
May 226:20 PM CDTEF0Jack, TX0.050
May 226:25 PM CDTEF1Ogle, IL29.1200$150,000
May 226:26 PM CDTEF0Price, WI0.8275
May 226:28 PM CDTEF1Ogle, IL1.7200$50,000
May 226:33 PM CDTEF2Delaware, OK6.7800$1.0 million
May 226:40 PM CDTEF1Ogle, IL0.5100$50,000
May 226:42 PM CDTEF1Wagoner, OK3.5300
May 226:52 PM CDTEF3Delaware, OK to MO17.91,5504$2.0 million
May 226:55 PM CDTEF1Winnebago, IL2.750
May 226:59 PM CDTEF1Winnebago, IL0.950$15,000
May 227:10 PM CDTEF2Stone, MO15.7200$1.1 million
May 227:27 PM CDTEF1Cherokee, OK3.0250$70,000
May 227:33 PM CDTEF0Green Lake, WI0.430$1,000
May 227:47 PM CDTEF0Green Lake, WI4.250$5,000
May 227:50 PM CDTEF0Cherokee, OK0.150
May 228:13 PM CDTEF1Delaware, OK4.7400$25,000
May 228:14 PM CDTEF2Adair, OK4.5200$250,000
May 228:29 PM CDTEF0Delaware, OK1.0100
May 228:30 PM CDTEF2Delaware, OK2.935012$400,000
May 228:36 PM CDTEF1Delaware, OK1.7150
May 228:41 PM CDTEF0Renville, ND0.125
May 228:44 PM CDTEF1Delaware, OK0.5100
May 228:54 PM CDTEF1Benton, AR2.8450$25,000

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.