Tornadoes · United States · Colorado · 2021

EF0 tornado, Karval, Colorado, April 27, 2021

This EF0 tornado ran 0.0 miles across Lincoln County on April 27, 2021, touching down at 3:57 PM MDT and reaching 50 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
April 27, 2021
Touchdown
3:57 PM MDT (21:57 UTC)
Lifted
3:58 PM MDT (21:58 UTC)
On the ground
1 minutes
Path length
0.0 miles (0.0 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Lincoln County
Touchdown point
38.640, -103.250
Lift-off point
38.640, -103.250
Record number
2104271557-01

What the Weather Service recorded

Severe thunderstorms developed across portions of Adams, Elbert, and Lincoln counties. Hail from quarter to ping pong ball size was observed. Near Limon and Messex, the hail completely covered the roadways. Two tornados also touched down briefly in Lincoln County but no damage was observed. Very heavy rain developed across the northeast plains. The heavy rain caused small stream flooding across southeast Logan and southwestern Phillips counties. The heavy rain and flooding forced the closure of State Highway 59, south of Haxtun. Storm totals ranged from 2 to 6 inches of rainfall.

A tornado briefly touched down in an open field. No damage was observed.

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

The warnings

16 minutes of warning. NWS BOU issued a tornado warning for this county at 21:41 UTC, 16 minutes before the tornado touched down, in force until 22:15 UTC.

The county was under a severe thunderstorm watch, issued at 17:45 UTC and running to 23:21 UTC.

Issued (UTC)ExpiredProductOffice
17:45 UTC23:21 UTCSevere Thunderstorm WatchBOU
20:23 UTC21:15 UTCSevere Thunderstorm WarningBOU
20:49 UTC21:30 UTCSevere Thunderstorm WarningBOU
21:28 UTC22:15 UTCSevere Thunderstorm WarningBOU
21:41 UTC22:15 UTCTornado WarningBOU
22:12 UTC22:45 UTCSevere Thunderstorm WarningBOU
22:36 UTC23:00 UTCTornado WarningBOU

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 Marginal Risk. The outlook in force was issued at 19:49 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.

Denver, CO (KDNR), 12:00Z

10.0 hours before the tornado, 137 km from the path. April 27, 2021.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2021-04-27Temperature 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 -82987, lifted condensation level 3214 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 12:00Z on 2021-04-27The 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 51 square meters per square second, 0 to 6 km bulk shear 67 knots.1939587897117Sfc1 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
-82987 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
3214 m above ground
0-6 km bulk shear
67 kt
0-1 km bulk shear
10 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
7.1 K/km

Open this sounding in Storm Lab

Denver, CO (KDNR), 00:00Z

2.0 hours after it, 137 km from the path. April 28, 2021.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2021-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 26 joules per kilogram, CIN -21, lifted condensation level 1024 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 00:00Z on 2021-04-28The 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 -2 square meters per square second, 0 to 6 km bulk shear 42 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
26 J/kg
Mixed-layer CIN
-21 J/kg
Surface CAPE
327 J/kg
Mixed-layer LCL
1024 m above ground
0-6 km bulk shear
42 kt
0-1 km bulk shear
1 kt
0-1 km storm-relative helicity
-2 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.0
0-3 km lapse rate
8.2 K/km

Open this sounding in Storm Lab

The surface observations

La Junta Municipal (LHX), 70 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:00 UTC 7 kt1003.7
20:05 UTC90° 8 kt1003.7
20:10 UTC80° 9 kt161003.4
20:15 UTC0° 0 kt1003.4
20:20 UTC0° 0 kt1003.4
20:25 UTC 1003.4
20:30 UTC80° 11 kt1003.4
20:35 UTC60° 8 kt1003
20:40 UTC70° 11 kt211003
20:45 UTC20° 9 kt1003
20:50 UTC40° 13 kt1003
20:53 UTC734020° 8 kt191003
20:55 UTC10° 11 kt1003
21:00 UTC30° 9 kt151003
21:05 UTC60° 10 kt1002.7
21:10 UTC50° 8 kt1002.7
21:15 UTC40° 5 kt1002.7
21:20 UTC40° 4 kt1002.7
21:25 UTC50° 2 kt1002.7
21:30 UTC110° 4 kt1002.7
21:35 UTC0° 0 kt1003
21:40 UTC250° 9 kt1003
21:50 UTC 16 kt271003
21:53 UTC7724.1190° 19 kt271003
21:55 UTC 16 kt221003
22:00 UTC200° 7 kt1003
22:05 UTC210° 7 kt1003
22:10 UTC120° 4 kt1002.7
22:15 UTC300° 11 kt1002.7
22:20 UTC310° 9 kt1002.7
22:25 UTC320° 4 kt1002.7
22:30 UTC 1002.7
22:35 UTC300° 14 kt1002.7
22:40 UTC300° 13 kt1003
22:45 UTC300° 8 kt1003
22:50 UTC290° 10 kt181003
22:53 UTC7724.1290° 11 kt191003
22:55 UTC300° 17 kt301003.4
23:00 UTC340° 331004.1
23:10 UTC6839340° 24 kt351004.4
23:10 UTC330° 301004.4
23:15 UTC340° 27 kt321004.4
23:20 UTC340° 22 kt271004.7
23:25 UTC330° 22 kt301004.7
23:35 UTC340° 19 kt1004.7
23:40 UTC340° 19 kt231004.7
23:45 UTC340° 21 kt261005.1
23:50 UTC340° 18 kt221004.7
23:53 UTC7138330° 18 kt291004.7
23:55 UTC330° 22 kt281005.1

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

The radar

The Pueblo radar (KPUX), 83 km away, was scanning. The volume nearest the touchdown began at 21:55 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
20:33 UTCTORNADO4 Se KutchLincoln, CODELAYED REPORT. A BRIEF TORNADO OCCURRED A FEW MILES WEST OF THE CO94/71 INTERSECTION JUST AFTER 2:30 PM, CONFIRMED BY STORM CHASER PHOTOS AND VIDEOS. LOCATION ESTIMATED BY RADAR.
20:47 UTCHAIL 13 W Punkin CenterLincoln, COSPOTTER NETWORK, NWS CHAT.
20:49 UTCHAIL 1.53 W Punkin CenterLincoln, COCORRECTS PREVIOUS HAIL REPORT FROM 3 W PUNKIN CENTER. SPOTTER NETWORK, NWS CHAT.
20:49 UTCHAIL 1.53 W Punkin CenterLincoln, COSPOTTER NETWORK, NWS CHAT.
21:23 UTCHAIL 110 Wsw HugoLincoln, COLI113.
21:28 UTCHAIL 14 Sse HugoLincoln, COLI216, HAIL COVERED GROUND TO 0.5-1.0 INCHES.
21:58 UTCTORNADO15 Ene Wild Horse PointLincoln, COSEVERAL TRAINED SPOTTERS REPORTED A TORNADO. LOCATION ESTIMATED BY RADAR.
22:10 UTCTORNADO14 Ssw Wild HorseCheyenne, COCORRECTS PREVIOUS TORNADO REPORT FROM 14 SSW WILD HORSE. DELAYED REPORT. CHEYENNE COUNTY SHERIFF REPORTED 3 TORNADOES WITH WALL CLOUDS. ADDITIONAL REPORTS RECEIVED FROM SPOTTERS LOOKING AT STORM FROM A LOCATION NORTH OF
22:10 UTCTORNADO14 Ssw Wild HorseCheyenne, CODELAYED REPORT. CHEYENNE COUNTY SHERIFF REPORTED 3 TORNADOES WITH WALL CLOUDS.
22:28 UTCHAIL 0.8815 S FlaglerKit Carson, COPEA TO NICKEL SIZED HAIL.
22:33 UTCTORNADO10 S Wild HorseCheyenne, CODELAYED REPORT. TORNADOES VIEWED ON LIVE CHASER STREAM.
22:56 UTCTORNADO2 W Kit CarsonCheyenne, CODELAYED REPORT VIA SOCIAL MEDIA. VIDEO OF A TORNADO CROSSED US-40.
23:03 UTCTSTM WND GST 603 Se Kit CarsonCheyenne, COTRAINED SPOTTER REPORTED 60 MPH WINDS THAT LASTED 2 MINUTES IN DURATION.

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

This ground now

The live radar over the trackEvery 2021 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

The other tornadoes of April 27, 2021

13 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 272:32 PM MDTEF0Lincoln, CO0.050
April 273:49 PM CDTEF3Knox, TX8.4400$70,000
April 274:08 PM MDTUnratedCheyenne, CO0.850
April 274:08 PM MDTUnratedCheyenne, CO2.0100
April 274:15 PM MDTUnratedCheyenne, CO2.075
April 274:16 PM MDTUnratedCheyenne, CO4.0300
April 274:28 PM MDTUnratedCheyenne, CO1.3100
April 274:54 PM MDTUnratedCheyenne, CO4.550
April 275:27 PM MDTUnratedCheyenne, CO1.975
April 277:15 PM CDTEF0Tillman, OK0.120
April 277:19 PM CDTUnratedWilbarger, TX0.230
April 277:47 PM CDTEF0Scurry, TX2.650
April 2712:00 AM CDTEF1Garvin, OK4.5150$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.