Tornadoes · United States · Colorado · 2019
EF0 tornado, Akron Arpt to Hyde, Colorado, August 11, 2019
From Akron Arpt to Hyde, this EF0 tornado ran 0.0 miles across Washington County on August 11, 2019, touching down at 4:09 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.
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
- August 11, 2019
- Touchdown
- 4:09 PM MDT (22:09 UTC)
- Lifted
- 4:10 PM MDT (22:10 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
- 40.165, -102.852
- Lift-off point
- 40.165, -102.852
- Record number
- 1908111609-01
The damage survey
5 damage points were recorded along this path by NWS BOU, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 70 mph.
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
Severe thunderstorm produced very large hail, damaging straight-line winds to around 65 mph and multiple tornadoes. Most of the damage occurred in Washington County where hail up to 4.5 inches in diameter was reported. The hail produced property and crop damage. In addition, six tornadoes touched down. One of the tornadoes snapped a few power lines near the Yuma County line.
A tornado touched down in an open field. No damage was observed.
A tornado touched down in an open field. No damage was observed.
A tornado touched down briefly in an open field. No damage was observed.
A tornado touched down in an open field. No damage was observed.
A tornado touched down and snapped a few power lines near the Yuma County line.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
29 minutes of warning. NWS BOU issued a tornado warning for this county at 21:40 UTC, 29 minutes before the tornado touched down, in force until 22:15 UTC.
The county was under a severe thunderstorm watch, issued at 19:25 UTC and running to 01:27 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 19:25 UTC | 01:27 UTC | Severe Thunderstorm Watch | BOU |
| 20:45 UTC | 21:15 UTC | Severe Thunderstorm Warning | BOU |
| 21:07 UTC | 21:45 UTC | Tornado Warning | BOU |
| 21:30 UTC | 22:00 UTC | Severe Thunderstorm Warning | BOU |
| 21:35 UTC | 22:00 UTC | Tornado Warning | BOU |
| 21:36 UTC | 22:27 UTC | Flood Advisory | BOU |
| 21:40 UTC | 22:15 UTC | Tornado Warning | BOU |
| 21:54 UTC | 22:30 UTC | Severe Thunderstorm Warning | BOU |
| 21:59 UTC | 22:30 UTC | Severe Thunderstorm Warning | BOU |
| 22:10 UTC | 22:30 UTC | Tornado Warning | 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 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:44 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
10.2 hours before the tornado, 46 km from the path. August 11, 2019.
- Mixed-layer CAPE
- 6 J/kg
- Mixed-layer CIN
- -342 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 1668 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km bulk shear
- 5 kt
- 0-1 km storm-relative helicity
- 4 m²/s²
- 0-3 km storm-relative helicity
- -68 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 5.9 K/km
Denver, CO (KDNR), 00:00Z
1.8 hours after it, 46 km from the path. August 12, 2019.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -179 J/kg
- Surface CAPE
- 169 J/kg
- Mixed-layer LCL
- 2259 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- -38 m²/s²
- 0-3 km storm-relative helicity
- -32 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
- 0-3 km lapse rate
- 7.7 K/km
The surface observations
Yuma (2V6), 14 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 20:14 UTC | 86 | 30.2 | 70° 12 kt | 16 | 1015.6 | |
| 20:34 UTC | 87.8 | 28.4 | 80° 12 kt | 18 | 1015.2 | |
| 20:54 UTC | 87.8 | 26.6 | 80° 17 kt | 1014.6 | ||
| 21:14 UTC | 87.8 | 26.6 | 70° 18 kt | 1014.2 | VCTS | |
| 21:29 UTC | 82.4 | 33.8 | 80° 13 kt | 19 | 1013.5 | |
| 21:49 UTC | 78.8 | 37.4 | 100° 10 kt | 15 | 1013.2 | VCTS |
| 22:14 UTC | 78.8 | 37.4 | 60° 16 kt | 1012.9 | ||
| 22:29 UTC | 75.2 | 33.8 | 50° 12 kt | 23 | 1013.5 | TS |
| 22:49 UTC | 77 | 35.6 | 20° 14 kt | 18 | 1013.5 | TS |
| 23:14 UTC | 73.4 | 35.6 | 40° 15 kt | 1012.5 | TS | |
| 23:34 UTC | 64.4 | 41 | 20° 20 kt | 27 | 1013.2 | TSRA |
| 23:54 UTC | 62.6 | 44.6 | 0° 0 kt | 1013.9 | -TSRA | |
| 00:09 UTC | 64.4 | 44.6 | 340° 3 kt | 1012.2 | VCTSRA |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Goodland radar (KGLD), 132 km away, was scanning. The volume nearest the touchdown began at 22:08 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 |
|---|---|---|---|---|
| 20:55 UTC | HAIL 1 | 6 Nw Akron | Washington, CO | |
| 21:00 UTC | HAIL 1.25 | 1 Nw Akron | Washington, CO | |
| 21:07 UTC | TORNADO | 3 Ne Akron | Washington, CO | |
| 21:07 UTC | TORNADO | 4 Ese Platner | Washington, CO | |
| 21:17 UTC | HAIL 1.5 | 1 N Akron | Washington, CO | AT THE AKRON AIRPORT |
| 21:26 UTC | TORNADO | 4 Nw Otis | Washington, CO | MULTIPLE REPORTS OF A TORNADO NORTHWEST OF OTIS. |
| 21:45 UTC | HAIL 0.75 | 7 Nne Yuma | Yuma, CO | LASTED 5 MINUTES. HAIL RANGED FROM HALF TO 3/4 INCHES IN DIAMETER. |
| 21:51 UTC | HAIL 2.5 | 3 W Otis | Washington, CO | |
| 21:55 UTC | HAIL 4 | Otis | Washington, CO | |
| 21:59 UTC | TORNADO | 3 E Otis | Washington, CO | |
| 22:00 UTC | HAIL 4.5 | Otis | Washington, CO | |
| 22:04 UTC | TORNADO | 7 S Clarkville | Yuma, CO | PUBLIC REPORTED POSSIBLE TORNADO ON THE GROUND. |
| 22:10 UTC | HAIL 1 | 10 Nw Wauneta | Yuma, CO | STILL ONGOING AS OF 4:25 PM MT. |
| 22:20 UTC | TORNADO | 6 Nw Yuma | Yuma, CO | PUBLIC REPORTED A TORNADO VIA TWITTER WITH A PICTURE. |
| 22:53 UTC | HAIL 2.5 | 9 N Yuma | Yuma, CO | TRAINED SPOTTER REPORTED 2.5 INCH HAIL 9 MILES N OF YUMA. |
| 22:53 UTC | TORNADO | 7 Wsw Wauneta | Yuma, CO | DELAYED REPORT. RELAYED BY YUMA COUNTY EMERGENCY MANAGER. PICTURES FORWARDED FROM PUBLIC SHOWING A TORNADO AND DAMAGE. TREES UPROOTED AND LIMBS BLOWN DOWN. |
| 22:55 UTC | HAIL 2.75 | 9 N Yuma | Yuma, CO | HAIL RANGED FROM GOLF BALL TO BASEBALL SIZE. SIGNIFICANT DAMAGE DONE TO WINDSHIELD. |
| 23:23 UTC | HAIL 1 | 7 Ese Clarkville | Yuma, CO | |
| 23:45 UTC | TSTM WND GST 80 | 4 N Wray | Yuma, CO | THERE IS SOME BLOWING DUST SEEN ON THE WEBCAM AT WRAY AS WELL WITH THIS STORM. |
| 00:00 UTC | TSTM WND DMG | 5 N Wray | Yuma, CO | REPORT VIA TWITTER. ONE DEAD TREE 2-3 FEET IN DIAMETER DOWN. SEVERAL OTHER LIVE TREES UP TO 1 FOOT IN DIAMETER DOWN. |
| 00:00 UTC | TSTM WND GST 75 | 5 N Wray | Yuma, CO | REPORT VIA TWITTER OF ESTIMATED 75 MPH WIND WITH GUSTS TO 85 MPH. SEVERAL TREES DOWN. |
| 00:15 UTC | TSTM WND GST 60 | 4 S Eckley | Yuma, CO | OCCURRED WITH QUARTER SIZE HAIL. |
| 00:15 UTC | HAIL 1 | 5 S Eckley | Yuma, CO | HAIL RANGED FROM NICKEL TO QUARTER IN SIZE. |
| 00:30 UTC | HAIL 1.5 | 5 Sw Wray | Yuma, CO | DELAYED REPORT: PUBLIC REPORTED VIA FACEBOOK COMMENT PING PONG BALL SIZED HAIL SW OF WRAY. TIME ESTIMATED BASED ON RADAR. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2019 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are
The other tornadoes of August 11, 2019
11 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| August 11 | 2:54 PM MDT | Unrated | Laramie, WY | 1.3 | 50 | |||
| August 11 | 3:04 PM MDT | EF0 | Washington, CO | 0.0 | 25 | |||
| August 11 | 3:26 PM MDT | EF0 | Washington, CO | 0.0 | 25 | |||
| August 11 | 3:59 PM MDT | EF0 | Washington, CO | 0.0 | 25 | |||
| August 11 | 4:03 PM MDT | EF0 | Washington, CO | 0.0 | 25 | |||
| August 11 | 4:04 PM MDT | Unrated | Yuma, CO | 0.0 | 50 | |||
| August 11 | 4:10 PM MDT | EF1 | Yuma, CO | 0.1 | 200 | |||
| August 11 | 4:59 PM MDT | EF1 | Yuma, CO | 1.6 | 100 | $70,000 | ||
| August 11 | 6:33 PM MDT | Unrated | Dundy, NE | 0.0 | 50 | |||
| August 11 | 7:47 PM CDT | EF1 | Cheyenne, KS | 1.2 | 175 | $50,000 | ||
| August 11 | 8:57 PM CDT | Unrated | Rawlins, KS | 0.9 | 50 |
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.