Tornadoes · United States · Oklahoma · 2019

EF2 tornado, Dale, Oklahoma, May 21, 2019

This EF2 tornado ran 2.6 miles across Pottawatomie County on May 21, 2019, touching down at 4:33 AM CDT and reaching 150 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 mphthis tornado

    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
EF2
Date
May 21, 2019
Touchdown
4:33 AM CDT (09:33 UTC)
Lifted
4:42 AM CDT (09:42 UTC)
On the ground
9 minutes
Path length
2.6 miles (4.2 km)
Path width
150 yards (137 m)
Deaths
0
Injuries
0
County
Pottawatomie County
Touchdown point
35.387, -97.028
Lift-off point
35.420, -97.014
Record number
1905210333-01

The damage survey

34 damage points were recorded along this path by NWS OUN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 127 mph.

  • Can observe path through trees across field to the east.
  • Clear narrow path crosses here. Shredded trees, which were also blocking road until they were moved. Path begins somewhere within a mile to the west, as no damage was observed on Choctaw Road.
  • lots of shredded trees. No damage observe3d on Peeply Road, so the tornado ended within 3/4 miles esat of here.
  • tree snapped to north. centerline just N of here

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

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

This QLCS tornado developed north of Interstate 40 about 1 mile east of Dale and moved north-northwest and then turned northeast to just west of Wolverine Road and Bethel Road. One mobile home was destroyed and several outbuildings were severely damaged on Westech Road near the beginning of the tornado path. Otherwise damage was generally to trees along the path.

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

The warnings

7 minutes of warning. NWS OUN issued a tornado warning for this county at 09:26 UTC, 7 minutes before the tornado touched down, in force until 10:00 UTC.

The county was under a tornado watch, issued at 03:19 UTC and running to 12:00 UTC.

Issued (UTC)ExpiredProductOffice
18:37 UTC03:00 UTCTornado WatchOUN
03:19 UTC12:00 UTCTornado WatchOUN
04:41 UTC05:18 UTCSevere Thunderstorm WarningOUN
07:55 UTC20:22 UTCFlood WarningOUN
09:24 UTC10:15 UTCSevere Thunderstorm WarningOUN
09:26 UTC10:00 UTCTornado WarningOUN
09:45 UTC10:30 UTCSevere Thunderstorm WarningOUN
11:34 UTC17:30 UTCFlood WarningOUN
17:06 UTC15:17 UTCFlood WarningOUN
23:37 UTC15:31 UTCFlood WarningOUN
02:46 UTC20:22 UTCFlood 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 Marginal Risk. The outlook in force was issued at 05:40 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.

Norman, OK (KOUN), 00:00Z

9.6 hours before the tornado, 40 km from the path. May 21, 2019.

Skew-T log-pSkew-T log-p diagram, Norman, OK 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 3095 joules per kilogram, CIN -2, lifted condensation level 733 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, Norman, OK 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 420 square meters per square second, 0 to 6 km bulk shear 65 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
3095 J/kg
Mixed-layer CIN
-2 J/kg
Surface CAPE
4175 J/kg
Mixed-layer LCL
733 m above ground
0-6 km bulk shear
65 kt
0-1 km bulk shear
42 kt
0-1 km storm-relative helicity
420 m²/s²
0-3 km storm-relative helicity
523 m²/s²
Significant tornado parameter
10.8
Supercell composite
43.6
0-3 km lapse rate
5.3 K/km

Open this sounding in Storm Lab

Norman, OK (KOUN), 12:00Z

2.4 hours after it, 40 km from the path. May 21, 2019.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z 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 -31721, lifted condensation level 742 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, Norman, OK at 12:00Z 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 -157 square meters per square second, 0 to 6 km bulk shear 66 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
0 J/kg
Mixed-layer CIN
-31721 J/kg
Surface CAPE
17 J/kg
Mixed-layer LCL
742 m above ground
0-6 km bulk shear
66 kt
0-1 km bulk shear
41 kt
0-1 km storm-relative helicity
-157 m²/s²
0-3 km storm-relative helicity
-324 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 radar

The Norman radar (KTLX), 25 km away, was scanning. The volume nearest the touchdown began at 09:32 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
06:39 UTCFLASH FLOOD1 Ene WarwickLincoln, OKWATER AND DEBRIS ON ROADWAY AT HIGHWAY 66. THE HIGHWAY WAS CLOSED BY ODOT.
08:30 UTCTSTM WND GST 601 W NewcastleMcclain, OK
08:34 UTCFLASH FLOOD6 W KendrickLincoln, OKHIGHWAY 18 CLOSED AT 840 ROAD. BRIDGE COMPLETELY UNDERWATER.
08:45 UTCTORNADO3 Se GoldsbyMcclain, OKAN EF1 TORNADO MOVED FROM 3 MILES SE OF GOLDSBY TO 1 MILE NORTH-NORTHWEST OF NOBLE IN CLEVELAND COUNTY FROM 3:45 TO 3:50 AM.
08:55 UTCTSTM WND GST 622 Nw NormanCleveland, OK
08:57 UTCTORNADO5 E NormanCleveland, OKAN EF1 TORNADO MOVED NORTH-NORTHEAST THEN NORTHWEST FROM ALAMEDA STREET BETWEEN 48TH AND 60TH AVENUES NE TO NORTHWEST OF TECUMSEH ROAD AND 60TH AVENUE NE.
09:13 UTCTORNADO5 Sse Stanley Draper LaCleveland, OKA BRIEF EF0 TORNADO DAMAGED TREES NEAR 84TH AVENUE NE AND FRANKLIN ROAD.
09:22 UTCTORNADO4 Nw StellaCleveland, OKAN EF1 TORNADO MOVED EAST FOR 1.4 MILES FROM SOUTHWEST OF SE 104TH STREET AND INDIAN MERIDIAN ROAD.
09:32 UTCTORNADO1 E DalePottawatomie, OKCAMPER FLIPPED OVER, HOME DAMAGED, TREES DAMAGED.
09:50 UTCTORNADO3 Ene AydelottePottawatomie, OKAN EF0 TORNADO MOVED NORTH AND NORTHEAST FROM JUST SOUTH OF THE LINCOLN-POTTAWATOMIE COUNTY LINE INTO LINCOLN COUNTY DISSIPATING ABOUT 3 MILES EAST-SOUTHEAST OF MEEKER.
12:15 UTCFLOODNormanCleveland, OKA FEW ROADS ARE CLOSED IN NORMAN DUE TO HIGH WATER.

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 21, 2019

30 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 213:45 AM CDTEF1McClain, OK3.8250$31,000
May 213:57 AM CDTEF1Cleveland, OK4.150$6,000
May 214:13 AM CDTEF0Cleveland, OK0.320$3,000
May 214:22 AM CDTEF1Cleveland, OK1.430
May 214:50 AM CDTEF0Lincoln, OK2.330$7,000
May 216:08 AM CDTEF1Creek, OK1.675
May 216:25 AM CDTUnratedMarshall, OK0.520
May 216:29 AM CDTEF0Tulsa, OK0.475
May 216:31 AM CDTEF1Tulsa, OK2.35501$125,000
May 216:37 AM CDTEF1Tulsa, OK0.775
May 216:48 AM CDTEF0Tulsa, OK0.6100
May 217:03 AM CDTEF1Atoka, OK1.6100$7,000
May 211:06 PM CDTEF0Greene, MO1.2100$41,000
May 212:48 PM CDTEF1Webster, MO7.1100$35,000
May 213:17 PM CDTEF1Wright, MO23.8200$5.0 million
May 214:18 PM CDTEF1Phelps, MO5.9800
May 214:32 PM CDTEF1Dickinson, KS7.5100
May 214:50 PM CDTEF0Rooks, KS0.250
May 214:52 PM CDTUnratedDickinson, KS17.7150
May 215:05 PM CDTEF1Callaway, MO0.6250
May 215:58 PM CDTEF1Franklin, MO5.9250
May 216:10 PM CDTEF0Shawnee, KS12.650
May 216:38 PM CDTEF2Jackson, KS17.175
May 217:01 PM CDTEF0Monroe, IL0.350
May 217:06 PM CDTEF0Nemaha, KS3.050
May 217:08 PM CDTEF1Atchison, KS5.430
May 217:20 PM CDTEF3Nemaha, KS5.9300
May 217:31 PM CDTUnratedRichardson, NE0.050
May 217:43 PM CDTUnratedRichardson, NE1.750
May 217:55 PM CDTEF0Nemaha, NE0.850

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.