Tornadoes · United States · Missouri · 2011

EF0 tornado, Appleton City, Missouri, May 11, 2011

This EF0 tornado ran 2.7 miles across St. Clair County on May 11, 2011, touching down at 8:35 PM CDT and reaching 50 yards wide. It killed nobody, and did $8,000 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 11, 2011
Touchdown
8:35 PM CDT (01:35 UTC)
Lifted
8:38 PM CDT (01:38 UTC)
On the ground
3 minutes
Path length
2.7 miles (4.3 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Property damage
$8,000
County
St. Clair County
Touchdown point
38.188, -94.037
Lift-off point
38.209, -93.995
Record number
1105111935-01

What the Weather Service recorded

An upper level low over western Kansas combined with a cold front moved into the region and produced severe thunderstorms. Numerous severe storms and a few supercells produced very large hail and high wind gusts as the front moved through the region.

A National Weather Service storm survey determined that an EF-0 tornado touched down near the western edge of Appleton City and continued intermittently to near 2.5 miles northeast of town. The tornado downed several trees and caused minor shingle and roof damage to a few homes.

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.

The county was under a severe thunderstorm watch, issued at 21:04 UTC and running to 02:50 UTC.

Issued (UTC)ExpiredProductOffice
21:04 UTC02:50 UTCSevere Thunderstorm WatchSGF

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 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 00:49 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.

Springfield, MO (KSGF), 00:00Z

1.6 hours before the tornado, 146 km from the path. May 12, 2011.

Skew-T log-pSkew-T log-p diagram, Springfield, MO at 00:00Z on 2011-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 882 joules per kilogram, CIN -21, lifted condensation level 1502 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, Springfield, MO at 00:00Z on 2011-05-12The 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 45 square meters per square second, 0 to 6 km bulk shear 30 knots.193958Sfc1 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
882 J/kg
Mixed-layer CIN
-21 J/kg
Surface CAPE
1747 J/kg
Mixed-layer LCL
1502 m above ground
0-6 km bulk shear
30 kt
0-1 km bulk shear
10 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
29 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.0
0-3 km lapse rate
7.1 K/km

Open this sounding in Storm Lab

Springfield, MO (KSGF), 12:00Z

10.4 hours after it, 146 km from the path. May 12, 2011.

Skew-T log-pSkew-T log-p diagram, Springfield, MO at 12:00Z on 2011-05-12Temperature 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 -71254, lifted condensation level 1317 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, Springfield, MO at 12:00Z on 2011-05-12The 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 180 square meters per square second, 0 to 6 km bulk shear 23 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
0 J/kg
Mixed-layer CIN
-71254 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1317 m above ground
0-6 km bulk shear
23 kt
0-1 km bulk shear
33 kt
0-1 km storm-relative helicity
180 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.6 K/km

Open this sounding in Storm Lab

The surface observations

Clinton (GLY), 34 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
23:35 UTC82.469.8140° 7 kt1008.1HZ
23:55 UTC80.669.8160° 5 kt1008.1HZ
00:15 UTC80.669.8160° 6 kt1008.5
00:35 UTC80.669.8150° 5 kt1008.5HZ
00:55 UTC78.869.8150° 4 kt1008.8HZ
01:15 UTC78.868150° 4 kt1008.5
01:35 UTC78.866.2150° 6 kt1008.5
01:55 UTC78.866.2150° 7 kt1008.8
02:15 UTC78.866.2240° 22 kt291010.8
02:35 UTC69.862.6260° 12 kt251011.2
02:55 UTC66.262.6240° 6 kt1011.9RA
03:15 UTC64.464.4210° 5 kt1011.5-RA

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

The radar

The Pleasant Hill radar (KEAX), 71 km away, was scanning. The volume nearest the touchdown began at 01:35 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
01:25 UTCTSTM WND DMG5 E Rich HillBates, MOBARN ROOF BLOWN OFF AT PAPPONSVILLE AND MACHINERY INSIDE MOVED SEVERAL FEET
01:30 UTCNON-TSTM WND DMGEl Dorado SpringsCedar, MOSEVERAL LIMBS DOWN AND A TREE DOWN WITH THE OUTFLOW BOUNDARY PASSAGE. TIME APPROXIMATED.
01:35 UTCTSTM WND DMG1 Wnw Appleton CitySt. Clair, MOTREE DOWN ON POWER LINE AND A FEW LIMBS DOWN ACROSS 5TH STREET
01:35 UTCNON-TSTM WND DMGTabervilleSt. Clair, MOTREE DOWN ACROSS HIGHWAY H ASSOCIATED WITH OUTFLOW BOUNDARY PASSAGE.
02:03 UTCTSTM WND DMG7 E Rich HillBates, MOTREE UPROOTED DOWNED POWER LINES.
02:07 UTCNON-TSTM WND DMGCollinsSt. Clair, MOSEVERAL BRANCHES DOWN ASSOCIATED WITH THE OUTFLOW BOUNDARY PASSAGE.

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 MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

The other tornadoes of May 11, 2011

15 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 111:40 PM CDTEF0Adams, NE0.125$25,000
May 111:55 PM CDTEF0Tarrant, TX0.550$30,000
May 112:30 PM CDTEF0Cooke, TX1.675$18,000
May 112:50 PM CDTEF1Hamilton, NE2.3200$150,000
May 113:00 PM CDTEF1Polk, NE2.375$100,000
May 114:20 PM CDTEF0Taylor, IA0.230
May 114:38 PM CDTEF1Taylor, IA0.7440$5.0 million
May 114:45 PM CDTEF1Taylor, IA1.0400$10 million
May 114:58 PM CDTEF0Adams, IA0.430
May 116:11 PM CDTEF0Mayes, OK0.550$10,000
May 116:47 PM CDTEF1Delaware, OK1.5200$250,000
May 116:53 PM CDTEF0Sioux, IA0.550
May 117:07 PM CDTEF0Osceola, IA0.550
May 117:23 PM CDTEF0McDonald, MO0.875$10,000
May 118:21 PM CDTEF0Bates, MO8.550$500

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.