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.

  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
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)ExpiredProductOffice
19:25 UTC01:27 UTCSevere Thunderstorm WatchBOU
20:45 UTC21:15 UTCSevere Thunderstorm WarningBOU
21:07 UTC21:45 UTCTornado WarningBOU
21:30 UTC22:00 UTCSevere Thunderstorm WarningBOU
21:35 UTC22:00 UTCTornado WarningBOU
21:36 UTC22:27 UTCFlood AdvisoryBOU
21:40 UTC22:15 UTCTornado WarningBOU
21:54 UTC22:30 UTCSevere Thunderstorm WarningBOU
21:59 UTC22:30 UTCSevere Thunderstorm WarningBOU
22:10 UTC22:30 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 0.05 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.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2019-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 6 joules per kilogram, CIN -342, lifted condensation level 1668 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, Denver, CO at 12:00Z on 2019-08-11The 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 4 square meters per square second, 0 to 6 km bulk shear 21 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
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

Open this sounding in Storm Lab

Denver, CO (KDNR), 00:00Z

1.8 hours after it, 46 km from the path. August 12, 2019.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2019-08-12Temperature 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 -179, lifted condensation level 2259 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, Denver, CO at 00:00Z on 2019-08-12The 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 -38 square meters per square second, 0 to 6 km bulk shear 31 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
-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

Open this sounding in Storm Lab

The surface observations

Yuma (2V6), 14 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:14 UTC8630.270° 12 kt161015.6
20:34 UTC87.828.480° 12 kt181015.2
20:54 UTC87.826.680° 17 kt1014.6
21:14 UTC87.826.670° 18 kt1014.2VCTS
21:29 UTC82.433.880° 13 kt191013.5
21:49 UTC78.837.4100° 10 kt151013.2VCTS
22:14 UTC78.837.460° 16 kt1012.9
22:29 UTC75.233.850° 12 kt231013.5TS
22:49 UTC7735.620° 14 kt181013.5TS
23:14 UTC73.435.640° 15 kt1012.5TS
23:34 UTC64.44120° 20 kt271013.2TSRA
23:54 UTC62.644.60° 0 kt1013.9-TSRA
00:09 UTC64.444.6340° 3 kt1012.2VCTSRA

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)ReportWhereCountyRemark
20:55 UTCHAIL 16 Nw AkronWashington, CO
21:00 UTCHAIL 1.251 Nw AkronWashington, CO
21:07 UTCTORNADO3 Ne AkronWashington, CO
21:07 UTCTORNADO4 Ese PlatnerWashington, CO
21:17 UTCHAIL 1.51 N AkronWashington, COAT THE AKRON AIRPORT
21:26 UTCTORNADO4 Nw OtisWashington, COMULTIPLE REPORTS OF A TORNADO NORTHWEST OF OTIS.
21:45 UTCHAIL 0.757 Nne YumaYuma, COLASTED 5 MINUTES. HAIL RANGED FROM HALF TO 3/4 INCHES IN DIAMETER.
21:51 UTCHAIL 2.53 W OtisWashington, CO
21:55 UTCHAIL 4OtisWashington, CO
21:59 UTCTORNADO3 E OtisWashington, CO
22:00 UTCHAIL 4.5OtisWashington, CO
22:04 UTCTORNADO7 S ClarkvilleYuma, COPUBLIC REPORTED POSSIBLE TORNADO ON THE GROUND.
22:10 UTCHAIL 110 Nw WaunetaYuma, COSTILL ONGOING AS OF 4:25 PM MT.
22:20 UTCTORNADO6 Nw YumaYuma, COPUBLIC REPORTED A TORNADO VIA TWITTER WITH A PICTURE.
22:53 UTCHAIL 2.59 N YumaYuma, COTRAINED SPOTTER REPORTED 2.5 INCH HAIL 9 MILES N OF YUMA.
22:53 UTCTORNADO7 Wsw WaunetaYuma, CODELAYED REPORT. RELAYED BY YUMA COUNTY EMERGENCY MANAGER. PICTURES FORWARDED FROM PUBLIC SHOWING A TORNADO AND DAMAGE. TREES UPROOTED AND LIMBS BLOWN DOWN.
22:55 UTCHAIL 2.759 N YumaYuma, COHAIL RANGED FROM GOLF BALL TO BASEBALL SIZE. SIGNIFICANT DAMAGE DONE TO WINDSHIELD.
23:23 UTCHAIL 17 Ese ClarkvilleYuma, CO
23:45 UTCTSTM WND GST 804 N WrayYuma, COTHERE IS SOME BLOWING DUST SEEN ON THE WEBCAM AT WRAY AS WELL WITH THIS STORM.
00:00 UTCTSTM WND DMG5 N WrayYuma, COREPORT VIA TWITTER. ONE DEAD TREE 2-3 FEET IN DIAMETER DOWN. SEVERAL OTHER LIVE TREES UP TO 1 FOOT IN DIAMETER DOWN.
00:00 UTCTSTM WND GST 755 N WrayYuma, COREPORT VIA TWITTER OF ESTIMATED 75 MPH WIND WITH GUSTS TO 85 MPH. SEVERAL TREES DOWN.
00:15 UTCTSTM WND GST 604 S EckleyYuma, COOCCURRED WITH QUARTER SIZE HAIL.
00:15 UTCHAIL 15 S EckleyYuma, COHAIL RANGED FROM NICKEL TO QUARTER IN SIZE.
00:30 UTCHAIL 1.55 Sw WrayYuma, CODELAYED 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.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 112:54 PM MDTUnratedLaramie, WY1.350
August 113:04 PM MDTEF0Washington, CO0.025
August 113:26 PM MDTEF0Washington, CO0.025
August 113:59 PM MDTEF0Washington, CO0.025
August 114:03 PM MDTEF0Washington, CO0.025
August 114:04 PM MDTUnratedYuma, CO0.050
August 114:10 PM MDTEF1Yuma, CO0.1200
August 114:59 PM MDTEF1Yuma, CO1.6100$70,000
August 116:33 PM MDTUnratedDundy, NE0.050
August 117:47 PM CDTEF1Cheyenne, KS1.2175$50,000
August 118:57 PM CDTUnratedRawlins, KS0.950

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.