Tornadoes · United States · Missouri · 2011

EF0 tornado, Westboro, Missouri, June 19, 2011

This EF0 tornado ran 0.5 miles across Atchison County on June 19, 2011, touching down at 10:07 PM CDT and reaching 40 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 19, 2011
Touchdown
10:07 PM CDT (03:07 UTC)
Lifted
10:08 PM CDT (03:08 UTC)
On the ground
1 minutes
Path length
0.5 miles (0.9 km)
Path width
40 yards (37 m)
Deaths
0
Injuries
0
County
Atchison County
Touchdown point
40.560, -95.380
Lift-off point
40.562, -95.370
Record number
1106192107-01

What the Weather Service recorded

An upper level storm system, moved across extreme northern Missouri, during the evening hours of June, 19, 2011. One weak tornado was observed in Atchison County Missouri.

At 2107CST an EF0 tornado touched down 3.8 miles west-northwest of Westboro. The tornado traveled about a half mile, and then lifted at 2108CST, 3.4 miles northwest of Westboro. The tornado was in an open field and did not cause any damage.

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

The warnings

26 minutes of warning. NWS EAX issued a tornado warning for this county at 02:41 UTC, 26 minutes before the tornado touched down, in force until 03:15 UTC.

The county was under a tornado watch, issued at 23:52 UTC and running to 07:00 UTC.

Issued (UTC)ExpiredProductOffice
12:10 UTC18:00 UTCFlash Flood WarningEAX
17:47 UTC17:30 UTCFlash Flood WarningEAX
23:52 UTC07:00 UTCTornado WatchEAX
02:41 UTC03:15 UTCTornado WarningEAX
03:11 UTC03:45 UTCTornado WarningEAX
20:10 UTC01:32 UTCTornado WatchEAX

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 01:01 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 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

3.1 hours before the tornado, 119 km from the path. June 20, 2011.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 2011-06-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2452 joules per kilogram, CIN -12, lifted condensation level 1426 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 00:00Z on 2011-06-20The 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 -15 square meters per square second, 0 to 6 km bulk shear 39 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
2452 J/kg
Mixed-layer CIN
-12 J/kg
Surface CAPE
3671 J/kg
Mixed-layer LCL
1426 m above ground
0-6 km bulk shear
39 kt
0-1 km bulk shear
9 kt
0-1 km storm-relative helicity
-15 m²/s²
0-3 km storm-relative helicity
106 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.2
0-3 km lapse rate
7.1 K/km

Open this sounding in Storm Lab

Omaha, NE (KOAX), 12:00Z

8.9 hours after it, 119 km from the path. June 20, 2011.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 12:00Z on 2011-06-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 104 joules per kilogram, CIN -396, lifted condensation level 1450 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 2011-06-20The 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 -142 square meters per square second, 0 to 6 km bulk shear 51 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
104 J/kg
Mixed-layer CIN
-396 J/kg
Surface CAPE
48 J/kg
Mixed-layer LCL
1450 m above ground
0-6 km bulk shear
51 kt
0-1 km bulk shear
9 kt
0-1 km storm-relative helicity
-142 m²/s²
0-3 km storm-relative helicity
188 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.5
0-3 km lapse rate
4.5 K/km

Open this sounding in Storm Lab

The radar

The Omaha radar (KOAX), 119 km away, was scanning. The volume nearest the touchdown began at 03:06 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
03:07 UTCTORNADO8 N TarkioAtchison, MOTORNADO NORTH OF TARKIO HEADING EAST NEAR 59 HWY

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 June 19, 2011

13 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 191:57 AM CDTEF0Crawford, MO1.360
June 191:58 AM CDTEF2Crawford, MO2.8803$150,000
June 193:48 AM CDTEF1Perry, IL3.22501$550,000
June 196:31 AM CDTEF0Perry, IN0.265
June 196:39 AM CDTEF2Breckinridge, KY1.060$50,000
June 196:43 AM CDTEF0Breckinridge, KY0.160$5,000
June 193:00 PM CDTEF0Winnebago, IA0.230
June 193:55 PM CDTEF0Dodge, WI0.120
June 195:44 PM MDTEF0Dundy, NE1.550$35,000
June 195:59 PM MDTEF0Sedgwick, CO0.150
June 196:01 PM MDTEF0Dundy, NE1.950
June 198:12 PM CDTEF0Morris, KS0.125
June 198:20 PM CDTEF0Red Willow, NE2.575

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.