Tornadoes · United States · Colorado · 2023

EF0 tornado, Woodrow to Akron, Colorado, May 10, 2023

From Woodrow to Akron, this EF0 tornado ran 0.0 miles across Washington County on May 10, 2023, touching down at 6:38 PM MDT and reaching 20 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 10, 2023
Touchdown
6:38 PM MDT (00:38 UTC)
Lifted
6:39 PM MDT (00:39 UTC)
On the ground
1 minutes
Path length
0.0 miles (0.0 km)
Path width
20 yards (18 m)
Deaths
0
Injuries
0
County
Washington County
Touchdown point
40.070, -103.330
Lift-off point
40.070, -103.330
Record number
2305101838-01

The damage survey

3 damage points were recorded along this path by NWS BOU, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 97 mph.

  • Tornado spotted in open field.
  • Tornado dissipated over open field.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

What the Weather Service recorded

Numerous severe thunderstorms developed southwest of Denver and pushed north-northeast through the metro area. The storms produced extensive hail, ranging from quarter to tennis ball size. As the storms move northeast onto the plains, the hail increase in size from baseball to softball size. In addition, the storm produced several tornadoes as they move across Morgan and Washington counties. Southeast of Brush, an EF1 tornado touched down and caused extensive damage to a residence. Part of the roof was torn off the residence. The nearby barn had a portion of its roof ripped off the building. Some wood storage buildings were destroyed and trees on the property were uprooted. The two elderly residence in the home at the time were not injured. Several other weaker tornadoes touched down in Washington County but no damage was observed.

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

A tornado touched down in open country. No damage was reported.

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

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

A weak tornado touched down briefly 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

27 minutes of warning. NWS BOU issued a tornado warning for this county at 00:11 UTC, 27 minutes before the tornado touched down, in force until 00:45 UTC.

The county was under a tornado watch, issued at 19:57 UTC and running to 01:38 UTC.

Issued (UTC)ExpiredProductOffice
19:57 UTC01:38 UTCTornado WatchBOU
23:49 UTC00:15 UTCTornado WarningBOU
00:05 UTC00:45 UTCSevere Thunderstorm WarningBOU
00:11 UTC00:45 UTCTornado WarningBOU
00:12 UTC03:15 UTCFlood AdvisoryBOU
00:39 UTC01:15 UTCTornado WarningBOU
12:00 UTC18:00 UTCFlood WatchBOU

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 19:52 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.

N. Platte/Lee Bi, NE (KLBF), 00:00Z

0.6 hours before the tornado, 259 km from the path. May 11, 2023.

Skew-T log-pSkew-T log-p diagram, N. Platte/Lee Bi, NE at 00:00Z on 2023-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1736 joules per kilogram, CIN -13, lifted condensation level 900 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 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, N. Platte/Lee Bi, NE at 00:00Z on 2023-05-11The 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 92 square meters per square second, 0 to 6 km bulk shear 24 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
1736 J/kg
Mixed-layer CIN
-13 J/kg
Surface CAPE
2269 J/kg
Mixed-layer LCL
900 m above ground
0-6 km bulk shear
24 kt
0-1 km bulk shear
26 kt
0-1 km storm-relative helicity
92 m²/s²
0-3 km storm-relative helicity
141 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.8
0-3 km lapse rate
6.6 K/km

Open this sounding in Storm Lab

N. Platte/Lee Bi, NE (KLBF), 12:00Z

11.4 hours after it, 259 km from the path. May 11, 2023.

Skew-T log-pSkew-T log-p diagram, N. Platte/Lee Bi, NE at 12:00Z on 2023-05-11Temperature 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 -97014, lifted condensation level 962 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 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, N. Platte/Lee Bi, NE at 12:00Z on 2023-05-11The 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 12 square meters per square second, 0 to 6 km bulk shear 30 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
0 J/kg
Mixed-layer CIN
-97014 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
962 m above ground
0-6 km bulk shear
30 kt
0-1 km bulk shear
4 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
143 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.8 K/km

Open this sounding in Storm Lab

The surface observations

Akron/Washington Co (AKO), 15 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
23:15 UTC80° 16 kt1008.5
23:20 UTC70° 14 kt191008.5
23:25 UTC70° 21 kt291008.5
23:40 UTC 311007.8
00:15 UTC90° 35 kt431006.1-RA
00:19 UTC6155100° 32 kt501007.8-TSRA
00:20 UTC 361008.5-RA
00:25 UTC 411009.8RA BR
00:30 UTC 331010.2+RA
00:35 UTC 361008.8+RA
00:40 UTC 221009.5-RA
00:45 UTC180° 11 kt191010.2-RA
00:50 UTC 15 kt1011.9-RA
00:53 UTC5653 6 kt221012.2-TSRA BR
00:55 UTC260° 4 kt1012.5RA BR
00:58 UTC5453 6 kt161012.9+TSRA BR
01:00 UTC60° 8 kt1012.2+RA BR
01:00 UTC535160° 8 kt161012.2+TSRA BR
01:05 UTC300° 4 kt1012.2+RA BR
01:10 UTC 241012.5+RA BR
01:10 UTC5148250° 17 kt261012.5+TSRA BR
01:14 UTC5249310° 14 kt281012.2+TSRA BR
01:15 UTC 221012.5+RA BR
01:20 UTC290° 20 kt281012.9-RA BR
01:20 UTC5250290° 21 kt291012.9-TSRA BR
01:22 UTC5350290° 21 kt291012.9-TSRA BR
01:25 UTC320° 15 kt1012.9-RA BR
01:30 UTC 211012.9-RA BR
01:31 UTC5350300° 15 kt1012.9VCTS -RA BR
01:35 UTC300° 13 kt1012.9-RA
01:40 UTC 1012.9-RA
01:40 UTC5451290° 12 kt1012.9-RA
01:45 UTC300° 10 kt1013.2-RA
01:50 UTC290° 10 kt1013.2-RA
01:53 UTC5351290° 9 kt1013.2-RA
01:55 UTC290° 9 kt1013.2-RA
02:00 UTC290° 8 kt1013.2-RA
02:05 UTC290° 8 kt1012.9-RA
02:10 UTC 1013.2-RA BR
02:15 UTC 1012.9-RA
02:20 UTC320° 13 kt1012.9-RA
02:25 UTC310° 11 kt1012.9-RA
02:30 UTC 1012.5-RA

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

The radar

The Denver radar (KFTG), 108 km away, was scanning. The volume nearest the touchdown began at 00:40 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
23:32 UTCHAIL 1.53 Sse AdenaAdams, CODELAYED REPORT VIA SPOTTERNETWORK.
23:32 UTCHAIL 1.53 Sse AdenaAdams, CODELAYED REPORT VIA SPOTTERNETWORK.
23:34 UTCHAIL 2.753 Ene WoodrowMorgan, COCORRECTS PREVIOUS HAIL REPORT FROM 3 ENE WOODROW.
23:35 UTCHAIL 1.752 Se AdenaAdams, CODELAYED REPORT VIA SPOTTERNETWORK.
23:35 UTCHAIL 1.752 Se AdenaAdams, CODELAYED REPORT VIA SPOTTERNETWORK.
23:38 UTCHAIL 2.52 Se AdenaAdams, CODELAYED REPORT VIA SPOTTERNETWORK.
23:38 UTCHAIL 2.52 Se AdenaAdams, CODELAYED REPORT VIA SPOTTERNETWORK.
23:51 UTCHAIL 32 Nne WoodrowMorgan, CODELAYED REPORT VIA SPOTTERNETWORK.
23:51 UTCHAIL 32 Nne WoodrowMorgan, CODELAYED REPORT VIA SPOTTERNETWORK.
23:54 UTCTORNADO7 Ene GaryWashington, COAPPROXIMATE LOCATION. TRAINED SPOTTERS REPORTED TORNADO ON THE GROUND.
23:55 UTCTORNADO9 Ene WoodrowWashington, COWEAK TORNADO.
00:10 UTCHAIL 37 Wsw AkronWashington, CO
00:13 UTCHAIL 46 Ene GaryMorgan, CO
00:14 UTCHAIL 2.753 Ene WoodrowMorgan, CO
00:18 UTCTORNADO 18 Sse MidwayWashington, COLANDSPOUT BRIEFLY ON GROUND.
00:18 UTCTORNADO8 Sse MidwayWashington, COCORRECTS PREVIOUS TORNADO REPORT FROM 8 SSE MIDWAY. LANDSPOUT BRIEFLY ON GROUND.
00:18 UTCTORNADO8 Sse MidwayWashington, COCORRECTS PREVIOUS TORNADO REPORT FROM 8 SSE MIDWAY. LANDSPOUT BRIEFLY ON GROUND.
00:19 UTCTSTM WND GST 58AkronWashington, COASOS STATION KAKO AKRON.
00:19 UTCTSTM WND GST 58AkronWashington, COASOS STATION KAKO AKRON.
00:20 UTCHAIL 22.5 Ssw HillroseMorgan, CO
00:21 UTCHAIL 2.52 Se SnyderMorgan, CODELAYED REPORT VIA SPOTTERNETWORK.
00:21 UTCHAIL 2.52 Se SnyderMorgan, CODELAYED REPORT VIA SPOTTERNETWORK.
00:21 UTCTORNADO2 W MidwayWashington, CO
00:23 UTCTORNADO5 S MidwayWashington, CO
00:25 UTCHAIL 2.756 Ssw MidwayWashington, COCORRECTS PREVIOUS HAIL REPORT FROM 6 SSW MIDWAY.
00:25 UTCHAIL 2.86 Ssw MidwayWashington, CO
00:30 UTCTORNADO4 S Fremont ButteWashington, CO
00:32 UTCTORNADO6 Wsw AkronWashington, CO
00:39 UTCTORNADO9 Sw AkronWashington, COWEAK TORNADO.

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

This ground now

The live radar over the trackEvery 2023 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

The other tornadoes of May 10, 2023

7 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 101:05 PM CDTUnratedJefferson, AR0.125
May 105:26 PM CDTUnratedSheridan, KS0.9100
May 105:54 PM MDTEF1Morgan, CO6.020$500,000
May 105:54 PM MDTEF0Washington, CO0.020
May 106:20 PM MDTEF0Washington, CO4.220
May 106:29 PM MDTEF0Washington, CO0.020
May 106:31 PM MDTEF0Washington, CO0.020

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.