Tornadoes · United States · Oklahoma · 2019

Unrated tornado, Hollis to Gould, Oklahoma, May 20, 2019

From Hollis to Gould, this Unrated tornado ran 0.5 miles across Harmon County on May 20, 2019, touching down at 4:37 PM CDT and reaching 50 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 mph

    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. Unratedthis tornado

    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
Unrated
Date
May 20, 2019
Touchdown
4:37 PM CDT (21:37 UTC)
Lifted
4:38 PM CDT (21:38 UTC)
On the ground
1 minutes
Path length
0.5 miles (0.8 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Harmon County
Touchdown point
34.659, -99.957
Lift-off point
34.659, -99.957
Record number
1905201537-01

What the Weather Service recorded

An extremely unstable environment led to widespread severe weather across Texas and Oklahoma on the 20th into the morning of the 21st.

Multiple storm chasers observed a tornado estimated to be about 3 miles southwest of Hollis. No damage was reported.

An off-duty NWS employee observed a brief tornado estimated to be about 3 miles east-northeast of Hollis. No damage was reported.

Multiple storm chasers observed a brief tornado estimated to be about 2 miles north-northeast of Gould. No damage was reported.

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

The warnings

42 minutes of warning. NWS OUN issued a tornado warning for this county at 20:55 UTC, 42 minutes before the tornado touched down, in force until 21:45 UTC.

The county was under a tornado watch, issued at 18:37 UTC and running to 03:00 UTC.

Issued (UTC)ExpiredProductOffice
12:00 UTC18:00 UTCFlood WatchOUN
18:37 UTC03:00 UTCTornado WatchOUN
20:55 UTC21:45 UTCTornado WarningOUN
21:39 UTC22:15 UTCTornado WarningOUN
21:56 UTC22:13 UTCTornado WarningOUN
22:39 UTC23:30 UTCSevere Thunderstorm WarningOUN
22:46 UTC23:11 UTCTornado WarningOUN
23:21 UTC23:45 UTCSevere Thunderstorm WarningOUN
23:35 UTC02:30 UTCFlood AdvisoryOUN
00:04 UTC00:45 UTCSevere Thunderstorm WarningOUN

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 High Risk, with a 0.45 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 20:02 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.

Amarillo Airport, TX (KAMA), 12:00Z

9.6 hours before the tornado, 171 km from the path. May 20, 2019.

Skew-T log-pSkew-T log-p diagram, Amarillo Airport, TX at 12:00Z on 2019-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 812 joules per kilogram, CIN -146, lifted condensation level 637 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, Amarillo Airport, TX at 12:00Z on 2019-05-20The 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 404 square meters per square second, 0 to 6 km bulk shear 57 knots.1939587897Sfc1 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
812 J/kg
Mixed-layer CIN
-146 J/kg
Surface CAPE
31 J/kg
Mixed-layer LCL
637 m above ground
0-6 km bulk shear
57 kt
0-1 km bulk shear
34 kt
0-1 km storm-relative helicity
404 m²/s²
0-3 km storm-relative helicity
461 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.5
0-3 km lapse rate
4.3 K/km

Open this sounding in Storm Lab

Amarillo Airport, TX (KAMA), 00:00Z

2.4 hours after it, 171 km from the path. May 21, 2019.

Skew-T log-pSkew-T log-p diagram, Amarillo Airport, TX at 00:00Z on 2019-05-21Temperature 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 -70126, lifted condensation level 1290 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, Amarillo Airport, TX at 00:00Z on 2019-05-21The 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 63 square meters per square second, 0 to 6 km bulk shear 92 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
-70126 J/kg
Surface CAPE
1 J/kg
Mixed-layer LCL
1290 m above ground
0-6 km bulk shear
92 kt
0-1 km bulk shear
33 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
186 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.1 K/km

Open this sounding in Storm Lab

The surface observations

Childress Municipal (CDS), 39 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:40 UTC160° 15 kt201001.4
19:45 UTC160° 19 kt1001.7
19:50 UTC160° 15 kt1001.4
19:53 UTC7969160° 18 kt271001.4
19:55 UTC160° 16 kt1001HZ
20:00 UTC160° 20 kt1000.7-RA
20:05 UTC160° 18 kt1001-RA
20:10 UTC160° 15 kt1000.3-RA
20:15 UTC160° 18 kt1000.7-RA
20:20 UTC170° 18 kt1000.7-RA
20:25 UTC170° 17 kt1001-RA
20:30 UTC170° 17 kt1000.7-RA
20:35 UTC170° 15 kt1001-RA
20:40 UTC180° 16 kt221000.7-RA BR
20:45 UTC 23 kt331000.7-RA
20:50 UTC170° 18 kt1000.7-RA BR
20:53 UTC7166180° 13 kt331001-RA
20:55 UTC180° 11 kt1001-RA
21:00 UTC200° 11 kt1000.7-RA BR
21:02 UTC7066180° 10 kt1000.3-TSRA BR
21:05 UTC150° 5 kt1000-RA
21:10 UTC150° 14 kt1000BR
21:13 UTC7469140° 11 kt16999.7TS HZ
21:15 UTC140° 9 kt999.7HZ
21:20 UTC130° 9 kt999.3HZ
21:23 UTC7567130° 11 kt999.3VCTS HZ
21:25 UTC130° 11 kt999.3HZ
21:30 UTC140° 11 kt999.3HZ
21:32 UTC7469130° 11 kt999HZ
21:35 UTC140° 10 kt999HZ
21:40 UTC140° 8 kt999HZ
21:41 UTC7569140° 8 kt999VCTS HZ
21:45 UTC130° 11 kt999HZ
21:50 UTC140° 10 kt999.3HZ
21:53 UTC7569140° 9 kt999HZ
21:55 UTC140° 9 kt999HZ
22:00 UTC140° 8 kt998.6HZ
22:01 UTC7469140° 8 kt999VCTS HZ
22:05 UTC150° 8 kt999.3HZ
22:10 UTC140° 10 kt999.7HZ
22:15 UTC140° 10 kt999.3HZ
22:20 UTC160° 7 kt999.7HZ
22:25 UTC7670170° 9 kt999.7HZ
22:25 UTC170° 9 kt999.7HZ
22:30 UTC160° 9 kt999HZ
22:32 UTC7670150° 9 kt999VCTS HZ
22:35 UTC130° 10 kt998.3HZ
22:40 UTC170° 4 kt998.6HZ
22:45 UTC 999HZ
22:50 UTC 10 kt999-RA
22:53 UTC696130° 7 kt999.3VCTS -RA
22:55 UTC 8 kt999.7-RA
23:00 UTC 18 kt1000.7
23:03 UTC6662350° 16 kt1001-TSRA
23:05 UTC 11 kt1001-RA
23:10 UTC 13 kt1000.3-RA
23:15 UTC 9 kt999.7
23:18 UTC656120° 8 kt1000VCTS
23:20 UTC50° 7 kt1000
23:25 UTC20° 7 kt1000.3
23:30 UTC360° 8 kt1000.3
23:35 UTC350° 4 kt1000.7

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

The radar

The Altus AFB radar (KFDR), 96 km away, was scanning. The volume nearest the touchdown began at 21:34 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
22:12 UTCTORNADO8 Sw MangumGreer, OK
23:00 UTCTSTM WND GST 583 W GouldHarmon, OK

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 OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

The other tornadoes of May 20, 2019

38 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 209:50 AM MSTEF0Coconino, AZ1.010
May 202:05 PM CDTUnratedDickens, TX1.030
May 203:00 PM CDTUnratedCottle, TX0.210
May 203:01 PM CDTEF0Cottle, TX1.920
May 203:29 PM CDTEF0Collingsworth, TX0.350
May 203:31 PM CDTUnratedKingfisher, OK0.540
May 203:43 PM CDTUnratedKingfisher, OK3.7150
May 203:46 PM CDTUnratedKingfisher, OK0.550
May 203:50 PM CDTEF1Logan, OK6.070$3,000
May 203:54 PM CDTUnratedLogan, OK1.040
May 204:08 PM CDTEF1Logan, OK0.340$1,000
May 204:14 PM CDTEF1Cherokee, KS2.2440$25,000
May 204:23 PM CDTEF1Noble, OK to KS, MO3.0100$75,000
May 204:23 PM CDTEF1Crawford, KS to MO10.71,200$1.1 million
May 204:36 PM CDTEF0Kingfisher, OK0.120
May 204:38 PM CDTEF0Kingfisher, OK0.120
May 204:45 PM CDTUnratedHarmon, OK0.330
May 204:55 PM CDTEF0Kingfisher, OK1.420
May 204:59 PM CDTUnratedHarmon, OK0.120
May 205:05 PM CDTEF1Noble, OK7.7100$75,000
May 205:09 PM CDTEF0Logan, OK0.350$1,000
May 205:12 PM CDTEF2Greer, OK11.01,200$300,000
May 205:23 PM CDTEF3Ector, TX5.8225$400,000
May 205:38 PM CDTUnratedNoble, OK0.230
May 205:38 PM CDTUnratedGreer, OK0.240
May 206:48 PM EDTEF0Lee, FL0.130$25,000
May 206:14 PM CDTUnratedKiowa, OK0.530
May 206:45 PM CDTUnratedJasper, MO0.250
May 206:47 PM CDTUnratedDickens, TX3.4300
May 206:52 PM CDTEF2Midland, TX6.61502$250,000
May 209:05 PM CDTEF0Tulsa, OK0.5100$2,000
May 209:08 PM CDTUnratedFisher, TX0.030
May 2010:01 PM CDTEF1Okmulgee, OK4.4450$25,000
May 2010:09 PM CDTEF0Wagoner, OK0.875
May 2010:29 PM CDTUnratedHaskell, TX0.030
May 2010:29 PM CDTEF2Cherokee, OK21.02,7001$950,000
May 2010:35 PM CDTEF1Mayes, OK3.61,100$10,000
May 2010:54 PM CDTEF1Delaware, OK6.9600$50,000

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.