Tornadoes · United States · Colorado · 2023
EF0 tornado, Woodrow to Akron, Colorado, May 10, 2023
From Woodrow to Akron, this EF0 tornado ran 4.2 miles across Washington County on May 10, 2023, touching down at 6:20 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.
EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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
- 6:20 PM MDT (00:20 UTC)
- Lifted
- 6:24 PM MDT (00:24 UTC)
- On the ground
- 4 minutes
- Path length
- 4.2 miles (6.7 km)
- Path width
- 20 yards (18 m)
- Deaths
- 0
- Injuries
- 0
- County
- Washington County
- Touchdown point
- 40.160, -103.420
- Lift-off point
- 40.220, -103.430
- Record number
- 2305101820-01
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
9 minutes of warning. NWS BOU issued a tornado warning for this county at 00:11 UTC, 9 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) | Expired | Product | Office |
|---|---|---|---|
| 19:57 UTC | 01:38 UTC | Tornado Watch | BOU |
| 23:49 UTC | 00:15 UTC | Tornado Warning | BOU |
| 00:05 UTC | 00:45 UTC | Severe Thunderstorm Warning | BOU |
| 00:11 UTC | 00:45 UTC | Tornado Warning | BOU |
| 00:12 UTC | 03:15 UTC | Flood Advisory | BOU |
| 00:39 UTC | 01:15 UTC | Tornado Warning | BOU |
| 12:00 UTC | 18:00 UTC | Flood Watch | BOU |
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
0.3 hours before the tornado, 260 km from the path. May 11, 2023.
- 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
N. Platte/Lee Bi, NE (KLBF), 12:00Z
11.7 hours after it, 260 km from the path. May 11, 2023.
- 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
The radar
The Denver radar (KFTG), 105 km away, was scanning. The volume nearest the touchdown began at 00:21 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) | Report | Where | County | Remark |
|---|---|---|---|---|
| 23:32 UTC | HAIL 1.5 | 3 Sse Adena | Adams, CO | DELAYED REPORT VIA SPOTTERNETWORK. |
| 23:32 UTC | HAIL 1.5 | 3 Sse Adena | Adams, CO | DELAYED REPORT VIA SPOTTERNETWORK. |
| 23:34 UTC | HAIL 2.75 | 3 Ene Woodrow | Morgan, CO | CORRECTS PREVIOUS HAIL REPORT FROM 3 ENE WOODROW. |
| 23:35 UTC | HAIL 1.75 | 2 Se Adena | Adams, CO | DELAYED REPORT VIA SPOTTERNETWORK. |
| 23:35 UTC | HAIL 1.75 | 2 Se Adena | Adams, CO | DELAYED REPORT VIA SPOTTERNETWORK. |
| 23:38 UTC | HAIL 2.5 | 2 Se Adena | Adams, CO | DELAYED REPORT VIA SPOTTERNETWORK. |
| 23:38 UTC | HAIL 2.5 | 2 Se Adena | Adams, CO | DELAYED REPORT VIA SPOTTERNETWORK. |
| 23:51 UTC | HAIL 3 | 2 Nne Woodrow | Morgan, CO | DELAYED REPORT VIA SPOTTERNETWORK. |
| 23:51 UTC | HAIL 3 | 2 Nne Woodrow | Morgan, CO | DELAYED REPORT VIA SPOTTERNETWORK. |
| 23:54 UTC | TORNADO | 7 Ene Gary | Washington, CO | APPROXIMATE LOCATION. TRAINED SPOTTERS REPORTED TORNADO ON THE GROUND. |
| 23:55 UTC | TORNADO | 9 Ene Woodrow | Washington, CO | WEAK TORNADO. |
| 00:10 UTC | HAIL 3 | 7 Wsw Akron | Washington, CO | |
| 00:13 UTC | HAIL 4 | 6 Ene Gary | Morgan, CO | |
| 00:14 UTC | HAIL 2.75 | 3 Ene Woodrow | Morgan, CO | |
| 00:18 UTC | TORNADO 1 | 8 Sse Midway | Washington, CO | LANDSPOUT BRIEFLY ON GROUND. |
| 00:18 UTC | TORNADO | 8 Sse Midway | Washington, CO | CORRECTS PREVIOUS TORNADO REPORT FROM 8 SSE MIDWAY. LANDSPOUT BRIEFLY ON GROUND. |
| 00:18 UTC | TORNADO | 8 Sse Midway | Washington, CO | CORRECTS PREVIOUS TORNADO REPORT FROM 8 SSE MIDWAY. LANDSPOUT BRIEFLY ON GROUND. |
| 00:19 UTC | TSTM WND GST 58 | Akron | Washington, CO | ASOS STATION KAKO AKRON. |
| 00:19 UTC | TSTM WND GST 58 | Akron | Washington, CO | ASOS STATION KAKO AKRON. |
| 00:20 UTC | HAIL 2 | 2.5 Ssw Hillrose | Morgan, CO | |
| 00:21 UTC | HAIL 2.5 | 2 Se Snyder | Morgan, CO | DELAYED REPORT VIA SPOTTERNETWORK. |
| 00:21 UTC | HAIL 2.5 | 2 Se Snyder | Morgan, CO | DELAYED REPORT VIA SPOTTERNETWORK. |
| 00:21 UTC | TORNADO | 2 W Midway | Washington, CO | |
| 00:23 UTC | TORNADO | 5 S Midway | Washington, CO | |
| 00:25 UTC | HAIL 2.75 | 6 Ssw Midway | Washington, CO | CORRECTS PREVIOUS HAIL REPORT FROM 6 SSW MIDWAY. |
| 00:25 UTC | HAIL 2.8 | 6 Ssw Midway | Washington, CO | |
| 00:30 UTC | TORNADO | 4 S Fremont Butte | Washington, CO | |
| 00:32 UTC | TORNADO | 6 Wsw Akron | Washington, CO | |
| 00:39 UTC | TORNADO | 9 Sw Akron | Washington, CO | WEAK 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.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| May 10 | 1:05 PM CDT | Unrated | Jefferson, AR | 0.1 | 25 | |||
| May 10 | 5:26 PM CDT | Unrated | Sheridan, KS | 0.9 | 100 | |||
| May 10 | 5:54 PM MDT | EF1 | Morgan, CO | 6.0 | 20 | $500,000 | ||
| May 10 | 5:54 PM MDT | EF0 | Washington, CO | 0.0 | 20 | |||
| May 10 | 6:29 PM MDT | EF0 | Washington, CO | 0.0 | 20 | |||
| May 10 | 6:31 PM MDT | EF0 | Washington, CO | 0.0 | 20 | |||
| May 10 | 6:38 PM MDT | EF0 | Washington, CO | 0.0 | 20 |
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.