Tornadoes · United States · Colorado · 2021

EF0 tornado, Woodrow to Akron Arpt, Colorado, May 23, 2021

From Woodrow to Akron Arpt, this EF0 tornado ran 0.0 miles across Washington County on May 23, 2021, touching down at 3:14 PM MDT and reaching 25 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
May 23, 2021
Touchdown
3:14 PM MDT (21:14 UTC)
Lifted
3:15 PM MDT (21:15 UTC)
On the ground
1 minutes
Path length
0.0 miles (0.0 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
County
Washington County
Touchdown point
40.210, -103.300
Lift-off point
40.210, -103.300
Record number
2105231514-01

What the Weather Service recorded

Severe thunderstorms developed across Lincoln, Logan and Washington counties. The storms produced damaging thunderstorms wind gusts to 70 mph, hail up to 3 inches in diameter, and 7 brief tornadoes. Two the tornadoes in Logan County were rated EF1; they knocked down several power poles along State Highway 61 east of Sterling and near Proctor.

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

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

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

The warnings

19 minutes of warning. NWS BOU issued a tornado warning for this county at 20:55 UTC, 19 minutes before the tornado touched down, in force until 21:15 UTC.

The county was under a tornado watch, issued at 18:08 UTC and running to 01:35 UTC.

Issued (UTC)ExpiredProductOffice
18:08 UTC01:35 UTCTornado WatchBOU
19:47 UTC20:15 UTCTornado WarningBOU
20:13 UTC20:45 UTCTornado WarningBOU
20:44 UTC21:15 UTCSevere Thunderstorm WarningBOU
20:55 UTC21:15 UTCTornado WarningBOU
21:11 UTC21:45 UTCTornado WarningBOU
21:14 UTC22:00 UTCSevere Thunderstorm WarningBOU
22:06 UTC00:40 UTCFlood AdvisoryBOU
22:43 UTC23:00 UTCTornado WarningBOU
22:58 UTC23:15 UTCTornado WarningBOU
23:12 UTC00:56 UTCFlood AdvisoryBOU
23:13 UTC23:45 UTCSevere Thunderstorm WarningBOU
23:31 UTC23:45 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 Enhanced Risk, with a 0.10 chance of a tornado within 25 miles. The outlook in force was issued at 19:53 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

9.2 hours before the tornado, 38 km from the path. May 23, 2021.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2021-05-23Temperature 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 -87064, lifted condensation level 1106 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 2021-05-23The 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 73 square meters per square second, 0 to 6 km bulk shear 59 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
-87064 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1106 m above ground
0-6 km bulk shear
59 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
177 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

Denver, CO (KDNR), 00:00Z

2.8 hours after it, 38 km from the path. May 24, 2021.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2021-05-24Temperature 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 -78658, lifted condensation level 3282 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 2021-05-24The 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 34 square meters per square second, 0 to 6 km bulk shear 60 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
-78658 J/kg
Surface CAPE
17 J/kg
Mixed-layer LCL
3282 m above ground
0-6 km bulk shear
60 kt
0-1 km bulk shear
8 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
132 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
9.5 K/km

Open this sounding in Storm Lab

The surface observations

Akron/Washington Co (AKO), 8 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:15 UTC150° 24 kt301014.2
19:20 UTC150° 23 kt301014.2
19:25 UTC150° 22 kt281014.2
19:30 UTC150° 20 kt281013.9
19:35 UTC150° 20 kt271014.2
19:40 UTC160° 27 kt341013.9
19:45 UTC150° 24 kt351013.9
19:50 UTC140° 21 kt301013.5
19:53 UTC7159150° 26 kt361013.2
19:55 UTC150° 23 kt291013.2
20:00 UTC150° 22 kt1013.5
20:05 UTC150° 21 kt351013.2
20:15 UTC140° 22 kt301012.9
20:20 UTC140° 23 kt311013.2
20:25 UTC140° 24 kt331012.5
20:30 UTC140° 18 kt231012.9
20:35 UTC140° 20 kt301012.5
20:40 UTC140° 20 kt291012.2
20:50 UTC6857.2140° 24 kt331012.2VCTS
20:53 UTC6858130° 22 kt331011.9VCTS
20:55 UTC130° 20 kt281011.9
21:00 UTC120° 20 kt241011.2
21:05 UTC120° 23 kt331010.5
21:10 UTC120° 22 kt301010.2
21:13 UTC6858120° 29 kt401009.5TS
21:15 UTC120° 29 kt391009.8
21:20 UTC 23 kt291010.8
21:30 UTC100° 22 kt291010.8
21:35 UTC160° 21 kt321011.2
21:40 UTC 22 kt32
21:44 UTC6451240° 16 kt341013.2VCTS
21:45 UTC 15 kt
21:50 UTC 11 kt
21:53 UTC5949260° 12 kt241012.9VCTS
22:05 UTC 1012.5
22:09 UTC5749250° 6 kt161012.2TS
22:10 UTC 7 kt1012.2
22:15 UTC 5 kt1011.9-RA
22:20 UTC 21 kt261012.2-RA
22:25 UTC 20 kt261012.5
22:30 UTC 23 kt31+RA
22:30 UTC5650210° 24 kt371013.2+TSRA
22:32 UTC5350180° 20 kt371012.9+TSRA BR
22:35 UTC170° 26 kt1012.2+RA FG
22:40 UTC150° 20 kt301011.5+RA FG
22:41 UTC5249150° 21 kt421011.5+TSRA FG
22:45 UTC170° 391011.9+RA BR
22:46 UTC5451180° 28 kt401011.2+TSRA BR
22:50 UTC 23 kt1010.5+RA BR
22:53 UTC5552190° 19 kt401010.2-TSRA BR
22:55 UTC5753190° 24 kt391010.5-TSRA BR
22:55 UTC190° 351010.5-RA BR
23:00 UTC170° 341010.2-RA
23:05 UTC6648180° 26 kt491010.5TS
23:10 UTC 18 kt231010.2

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

The radar

The Denver radar (KFTG), 116 km away, was scanning. The volume nearest the touchdown began at 21:15 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
20:25 UTCTORNADO2 N Last ChanceWashington, COPRELIMINARY.
20:25 UTCTORNADO7 Sw MidwayWashington, COFACING WNW.
20:53 UTCTORNADO10 Ene WoodrowWashington, COBRIEF TOUCHDOWN - NOTED BY DUST SWIRL ON THE GROUND BENEATH A FUNNEL (NOT FULLY CONDENSED).
20:57 UTCTORNADO10 Ese GaryWashington, COMULTIPLE REPORTS FROM THE SPOTTERNETWORK, LAW ENFORCEMENT, TWITTER.
20:57 UTCTORNADO10 Ese GaryWashington, COON GROUND FOR ABOUT 5 MINUTES. MULTIPLE REPORTS FROM THE SPOTTERNETWORK, LAW ENFORCEMENT, TWITTER.
21:15 UTCTORNADO3 S Fremont ButteWashington, CO
21:58 UTCHAIL 13 E AtwoodLogan, CO
22:00 UTCTORNADO4 Ese SterlingLogan, COPOWER POLES DOWN ON HIGHWAY 61. LIKELY TORNADO DAMAGE. EXACT LOCATION AND TIME APPROXIMATE.
22:00 UTCTORNADO4 Ese SterlingLogan, COPOWER POLES DOWN ON HIGHWAY 61. LIKELY TORNADO DAMAGE. EXACT LOCATION AND TIME APPROXIMATE.
22:40 UTCTSTM WND GST 612 E SterlingLogan, COMESONET STATION I-76.
23:21 UTCTSTM WND GST 584 W PlatnerWashington, COCSU01 COAGMET STATION.
23:47 UTCTSTM WND GST 611 Sse YumaYuma, CO

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 May 23, 2021

11 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 232:00 PM MDTEF0Lincoln, CO0.025
May 232:24 PM MDTEF0Washington, CO0.025
May 232:52 PM MDTEF0Washington, CO0.725
May 233:49 PM MDTEF1Logan, CO0.150
May 233:50 PM MDTUnratedPerkins, SD2.110
May 233:55 PM MDTEF1Custer, SD6.620
May 233:58 PM MDTUnratedPerkins, SD4.310
May 234:04 PM MDTEF1Custer, SD5.910
May 234:19 PM MDTEF0Logan, CO0.025
May 234:29 PM MDTEF1Logan, CO0.150
May 234:45 PM MDTEF0Lincoln, CO0.525

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.