Tornadoes · United States · Colorado · 2012

EF2 tornado, Lamar Arpt to Wiley, Colorado, April 27, 2012

From Lamar Arpt to Wiley, this EF2 tornado ran 2.0 miles across Prowers County on April 27, 2012, touching down at 1:49 AM MDT and reaching 200 yards wide. It killed nobody, and did $500,000 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 mph

    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 mphthis tornado

    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
EF2
Date
April 27, 2012
Touchdown
1:49 AM MDT (07:49 UTC)
Lifted
1:53 AM MDT (07:53 UTC)
On the ground
4 minutes
Path length
2.0 miles (3.2 km)
Path width
200 yards (183 m)
Deaths
0
Injuries
0
Property damage
$500,000
County
Prowers County
Touchdown point
37.991, -102.703
Lift-off point
38.022, -102.713
Record number
1204270149-01

What the Weather Service recorded

Five separate tornadoes occurred across Bent...Prowers...and Kiowa Counties...causing EF0 to EF2 damage. Eight people were injured...and one horse was killed. Four dwelling were destroyed...along with two mobile homes...one garage...and a metal building. A hog farm was destroyed...including 18 hog barns. Horse corrals were also damaged and destroyed. An electrical substation southeast of Lamar was damaged which contributed to a massive power outage in the Lamar area until the late afternoon hours. Two communication towers were also destroyed.

A hog farm was struck with 18 hog barns destroyed. There were no hogs on the farm at the time.

This long-track tornado began southeast of Lamar and damaged an electrical substation along county road EE. A power outage in the Lamar area lasted for over 12 hours. Two communication towers were downed...and four dwellings were destroyed.

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

The warnings

24 minutes of warning. NWS PUB issued a tornado warning for this county at 07:25 UTC, 24 minutes before the tornado touched down, in force until 08:15 UTC.

The county was under a severe thunderstorm watch, issued at 03:05 UTC and running to 10:00 UTC.

Issued (UTC)ExpiredProductOffice
20:42 UTC03:00 UTCSevere Thunderstorm WatchPUB
21:13 UTC21:42 UTCSevere Thunderstorm WarningPUB
21:31 UTC22:15 UTCSevere Thunderstorm WarningPUB
22:26 UTC22:43 UTCSevere Thunderstorm WarningPUB
22:42 UTC23:30 UTCSevere Thunderstorm WarningPUB
23:28 UTC00:00 UTCSevere Thunderstorm WarningPUB
00:36 UTC01:00 UTCSevere Thunderstorm WarningPUB
00:56 UTC01:45 UTCSevere Thunderstorm WarningPUB
01:30 UTC02:00 UTCSevere Thunderstorm WarningPUB
03:05 UTC10:00 UTCSevere Thunderstorm WatchPUB
07:09 UTC08:00 UTCSevere Thunderstorm WarningPUB
07:25 UTC08:15 UTCTornado WarningPUB
07:44 UTC08:03 UTCTornado WarningPUB
07:55 UTC08:45 UTCTornado WarningPUB
08:21 UTC08:34 UTCTornado WarningPUB
08:43 UTC09:15 UTCTornado WarningPUB

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 General Thunderstorms Risk. The outlook in force was issued at 05:36 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), 00:00Z

7.8 hours before the tornado, 212 km from the path. April 27, 2012.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2012-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 95 joules per kilogram, CIN -85, lifted condensation level 2538 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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, Denver, CO at 00:00Z on 2012-04-27The 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 42 square meters per square second, 0 to 6 km bulk shear 28 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
95 J/kg
Mixed-layer CIN
-85 J/kg
Surface CAPE
571 J/kg
Mixed-layer LCL
2538 m above ground
0-6 km bulk shear
28 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
175 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0
0-3 km lapse rate
8.7 K/km

Open this sounding in Storm Lab

Denver, CO (KDNR), 12:00Z

4.2 hours after it, 212 km from the path. April 27, 2012.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2012-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 145 joules per kilogram, CIN -1, lifted condensation level 557 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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, Denver, CO at 12:00Z on 2012-04-27The 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 -78 square meters per square second, 0 to 6 km bulk shear 8 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
145 J/kg
Mixed-layer CIN
-1 J/kg
Surface CAPE
363 J/kg
Mixed-layer LCL
557 m above ground
0-6 km bulk shear
8 kt
0-1 km bulk shear
11 kt
0-1 km storm-relative helicity
-78 m²/s²
0-3 km storm-relative helicity
-132 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.4
0-3 km lapse rate
6.4 K/km

Open this sounding in Storm Lab

The radar

The Pueblo radar (KPUX), 138 km away, was scanning. The volume nearest the touchdown began at 07:49 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
07:55 UTCFUNNEL CLOUD3 S LamarProwers, CO
07:58 UTCTORNADO3 Se LamarProwers, CODAMAGE TO AN ELECTRICAL SUBSTATION ALONG COUNTY ROAD EE. TIME APPROXIMATE.
08:40 UTCTORNADO10 Ne LamarProwers, COPUBLIC REPORT VIA PROWERS COUNTY COMMS...TIME APPROXIMATE

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

This ground now

The live radar over the trackEvery 2012 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

The other tornadoes of April 27, 2012

7 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 271:44 AM MDTEF2Bent, CO6.2300$25,000
April 271:58 AM MDTEF2Prowers, CO19.12007$500,000
April 272:35 AM MDTEF1Kiowa, CO2.21001$40,000
April 272:40 AM MDTEF2Kiowa, CO0.750$30,000
April 274:38 PM CDTEF0Cloud, KS2.0100
April 274:43 PM CDTEF0Phillips, KS4.440
April 275:59 PM CDTEF0Morris, KS0.010

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.