Tornadoes · United States · Colorado · 2011

EF0 tornado, Wild Horse, Colorado, June 18, 2011

This EF0 tornado ran 0.3 miles across Cheyenne County on June 18, 2011, touching down at 3:52 PM MDT and reaching 10 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 18, 2011
Touchdown
3:52 PM MDT (21:52 UTC)
Lifted
3:53 PM MDT (21:53 UTC)
On the ground
1 minutes
Path length
0.3 miles (0.5 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
County
Cheyenne County
Touchdown point
38.914, -102.950
Lift-off point
38.914, -102.950
Record number
1106181552-01

What the Weather Service recorded

A supercell thunderstorm, embedded in a line of storms, moved southeast across Cheyenne County during the afternoon producing a tornado, wind damage and hail up to baseball size. The storms eventually moved into western Kansas and produced another brief tornado and marginally severe wind and hail before weakening.

The tornado remained over open fields with no known damage.

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

The warnings

36 minutes of warning. NWS GLD issued a tornado warning for this county at 21:16 UTC, 36 minutes before the tornado touched down, in force until 22:00 UTC.

The county was under a severe thunderstorm watch, issued at 18:37 UTC and running to 02:00 UTC.

Issued (UTC)ExpiredProductOffice
18:37 UTC02:00 UTCSevere Thunderstorm WatchGLD
21:08 UTC22:15 UTCSevere Thunderstorm WarningGLD
21:16 UTC22:00 UTCTornado WarningGLD
21:57 UTC22:45 UTCTornado WarningGLD
22:28 UTC23:15 UTCTornado WarningGLD
23:13 UTC00:00 UTCTornado WarningGLD

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 21:16 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.

Denver, CO (KDNR), 12:00Z

9.9 hours before the tornado, 109 km from the path. June 18, 2011.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2011-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 110 joules per kilogram, CIN -160, lifted condensation level 1171 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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, Denver, CO at 12:00Z on 2011-06-18The 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 55 square meters per square second, 0 to 6 km bulk shear 34 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
110 J/kg
Mixed-layer CIN
-160 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1171 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
10 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.2 K/km

Open this sounding in Storm Lab

Denver, CO (KDNR), 00:00Z

2.1 hours after it, 109 km from the path. June 19, 2011.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2011-06-19Temperature 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 -71269, lifted condensation level 3912 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 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, Denver, CO at 00:00Z on 2011-06-19The 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 -30 square meters per square second, 0 to 6 km bulk shear 63 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
-71269 J/kg
Surface CAPE
15 J/kg
Mixed-layer LCL
3912 m above ground
0-6 km bulk shear
63 kt
0-1 km bulk shear
4 kt
0-1 km storm-relative helicity
-30 m²/s²
0-3 km storm-relative helicity
112 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
9.6 K/km

Open this sounding in Storm Lab

The surface observations

Burlington (ITR), 68 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:53 UTC80500° 6 kt1012.9
20:53 UTC7949120° 6 kt1012.5
21:53 UTC7752330° 5 kt1012.2
22:18 UTC60.853.6350° 25 kt351013.5+RA
22:23 UTC60.853.6360° 21 kt321013.9-RA
22:53 UTC6052140° 20 kt1011.5-RA

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

The radar

The Pueblo radar (KPUX), 118 km away, was scanning. The volume nearest the touchdown began at 21:49 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
21:34 UTCFUNNEL CLOUD11 N Wild HorseCheyenne, CO
21:40 UTCHAIL 1.7513 Nnw Wild HorseCheyenne, CO
21:50 UTCTSTM WND DMG6 N Wild HorseCheyenne, CO5 AND 9 INCH LIMBS TORN FROM TREES. 10 FT. LONG EMPTY STOCK TANK BLOWN 1/8 MILE. 10 FT. LONG METAL FEEDER DAMAGED AND BLOWN 1/16 MILE. ESTIMATED TIME OF REPORT FROM RADAR AND NEARBY STORM REPORTS.
21:52 UTCTORNADO5 Nne Wild HorseCheyenne, COVIA STORM CHASER VIDEO
22:10 UTCHAIL 1.7511 Nne Wild HorseCheyenne, CO
22:12 UTCHAIL 1.259 N Kit CarsonCheyenne, CO
22:13 UTCHAIL 19 Nne Kit CarsonCheyenne, CO
22:17 UTCHAIL 1.59 Nne Kit CarsonCheyenne, CO
22:23 UTCFUNNEL CLOUD10 Nne Kit CarsonCheyenne, COTHROUGH FIRE DEPARTMENT
22:29 UTCTORNADO3 Se Kit CarsonCheyenne, CO
22:30 UTCTSTM WND DMGKit CarsonCheyenne, CO5 TO 6 INCH DIAMETER TREE LIMBS DOWN AROUND TOWN. TIME APPROXIMATE.
22:30 UTCTORNADO2 W FirstviewCheyenne, CO
22:31 UTCTORNADO9 Se Kit CarsonCheyenne, CO
23:00 UTCFUNNEL CLOUD4 S Cheyenne WellsCheyenne, CO
23:05 UTCHAIL 44 S Cheyenne WellsCheyenne, CO
23:10 UTCHAIL 0.885 W Kit CarsonCheyenne, CO
23:22 UTCTSTM WND GST 758 S Cheyenne WellsCheyenne, CODIME TO QUARTER SIZE HAIL FALLING ALSO
23:34 UTCTSTM WND DMG9 Se Kit CarsonCheyenne, COPOWER POLE SNAPPED OFF AT BASE

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 ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

The other tornadoes of June 18, 2011

10 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 182:00 PM MDTEF0Scotts Bluff, NE0.025
June 184:24 PM MDTEF0Cheyenne, CO0.310
June 187:29 PM CDTEF0Osage, OK0.150
June 187:40 PM CDTEF0Gove, KS0.310
June 188:09 PM CDTEF0Osage, OK0.150
June 188:10 PM CDTEF0Osage, OK2.975
June 189:13 PM CDTEF0Washington, OK0.150
June 1811:35 PM CDTEF1Dade, MO10.9200
June 1811:40 PM CDTEF1Dade, MO6.0100$5,000
June 1812:03 AM CDTEF0Greene, MO2.8100$30,000

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.