Tornadoes · United States · Oklahoma · 2023

EF0 tornado, Tonkawa, Oklahoma, May 12, 2023

This EF0 tornado ran 0.3 miles across Kay County on May 12, 2023, touching down at 8:06 PM CDT and reaching 10 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
May 12, 2023
Touchdown
8:06 PM CDT (01:06 UTC)
Lifted
8:07 PM CDT (01:07 UTC)
On the ground
1 minutes
Path length
0.3 miles (0.5 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
County
Kay County
Touchdown point
36.660, -97.335
Lift-off point
36.660, -97.335
Record number
2305121906-01

What the Weather Service recorded

Scattered strong to severe thunderstorms developed from border-to-border in the forecast area, along a cold front that extended from the West Texas Plains into Missouri River Valley. Supportive magnitudes of instability and wind shear allowed for all severe hazards to be observed. In addition to large hail and damaging winds with the strongest storms, a well-documented tornado occurred near Tonkawa in Kay County, OK.

A number of spotters and chasers observed this tornado estimated to be about 2 miles southwest of Tonkawa. Some light tree damage was reported.

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

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

The county was under a severe thunderstorm watch, issued at 20:42 UTC and running to 07:00 UTC.

Issued (UTC)ExpiredProductOffice
20:42 UTC07:00 UTCSevere Thunderstorm WatchOUN
22:58 UTC23:45 UTCSevere Thunderstorm WarningOUN
23:36 UTC00:15 UTCSevere Thunderstorm WarningOUN
00:11 UTC01:00 UTCSevere Thunderstorm WarningOUN
00:38 UTC03:45 UTCFlood AdvisoryOUN
00:55 UTC01:45 UTCSevere Thunderstorm WarningOUN
01:07 UTC01:30 UTCTornado WarningOUN
01:08 UTC04:15 UTCFlood AdvisoryOUN
01:16 UTC01:45 UTCTornado WarningOUN
01:25 UTC02:00 UTCTornado WarningOUN
01:29 UTC01:51 UTCSevere Thunderstorm WarningOUN
01:57 UTC02:16 UTCTornado WarningOUN
02:17 UTC03:00 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 Marginal Risk. The outlook in force was issued at 01:01 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

1.1 hours before the tornado, 160 km from the path. May 13, 2023.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2023-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 3755 joules per kilogram, CIN -20, lifted condensation level 1086 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 2023-05-13The 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 62 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
3755 J/kg
Mixed-layer CIN
-20 J/kg
Surface CAPE
4980 J/kg
Mixed-layer LCL
1086 m above ground
0-6 km bulk shear
31 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
62 m²/s²
0-3 km storm-relative helicity
98 m²/s²
Significant tornado parameter
1.0
Supercell composite
6.5
0-3 km lapse rate
6.6 K/km

Open this sounding in Storm Lab

Norman, OK (KOUN), 12:00Z

10.9 hours after it, 160 km from the path. May 13, 2023.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z on 2023-05-13Temperature 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 -87187, lifted condensation level 1899 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 2023-05-13The 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 -168 square meters per square second, 0 to 6 km bulk shear 35 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
-87187 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1899 m above ground
0-6 km bulk shear
35 kt
0-1 km bulk shear
19 kt
0-1 km storm-relative helicity
-168 m²/s²
0-3 km storm-relative helicity
-77 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 surface observations

Blackwell (BKN), 10 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
23:15 UTC89.666.2180° 9 kt151009.1
23:35 UTC84.266.2130° 17 kt221009.5
23:55 UTC80.664.4130° 15 kt231010.2
00:15 UTC7766.290° 10 kt171010.5
00:35 UTC78.864.4120° 12 kt181010.5
00:55 UTC78.866.280° 10 kt1010.2
01:15 UTC78.864.4 4 kt121010.2
01:55 UTC78.857.290° 6 kt151010.2
02:15 UTC73.460.8150° 5 kt1010.2
02:35 UTC73.460.8160° 6 kt1010.2
02:55 UTC73.462.6180° 7 kt1010.5

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

The radar

The Vance AFB radar (KVNX), 71 km away, was scanning. The volume nearest the touchdown began at 01:07 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
23:10 UTCHAIL 1.75Ponca CityKay, OKPHOTO VIA TWITTER.
23:15 UTCHAIL 13 Nne Ponca CityKay, OKREPORT FROM MPING: QUARTER (1.00 IN.).
23:42 UTCHAIL 21 E Ponca CityKay, OKPHOTO VIA TWITTER.
23:51 UTCHAIL 17 Se BlackwellKay, OKREPORT FROM MPING: QUARTER (1.00 IN.).
01:03 UTCHAIL 1.75TonkawaKay, OK
01:07 UTCTORNADO3 Sw TonkawaKay, OKVIA TWITTER/NWSCHAT.
01:24 UTCHAIL 2TonkawaKay, OK
03:50 UTCTSTM WND DMGPawneePawnee, OKDELAYED REPORT. DAMAGE TO TREES AND A METAL CARPORT NEAR PAWNEE FROM FRIDAY NIGHT. PHOTOS AND OTHER INFORMATION RELAYED BY BROADCAST MEDIA.

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

The other tornadoes of May 12, 2023

32 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 1212:34 PM CDTEF1Custer, NE4.0100
May 1212:39 PM CDTUnratedLogan, NE0.110
May 1212:42 PM CDTUnratedCuster, NE0.11
May 1212:47 PM CDTUnratedCuster, NE0.110
May 122:25 PM CDTEF1Greeley, NE13.6200$300,000
May 123:11 PM CDTEF1Wheeler, NE3.450
May 123:25 PM CDTUnratedWheeler, NE0.150
May 123:55 PM CDTUnratedPlatte, NE0.150
May 123:55 PM CDTEF2Wheeler, NE7.375
May 124:00 PM CDTUnratedCuster, NE0.110
May 124:09 PM CDTEF1Boone, NE1.3150
May 124:22 PM CDTUnratedMadison, NE0.150
May 124:33 PM CDTEF1Pawnee, NE3.080
May 124:53 PM CDTEF1Stanton, NE8.9200
May 125:01 PM CDTEF1Madison, NE3.150
May 125:15 PM CDTEF2Dodge, NE5.5800
May 125:17 PM CDTEF1Stanton, NE5.0150
May 125:34 PM CDTEF1Stanton, NE2.8200
May 125:39 PM CDTEF1Stanton, NE5.1300
May 125:42 PM CDTEF0Dodge, NE2.5300
May 125:46 PM CDTEF2Dodge, NE10.41,600
May 126:14 PM CDTEF1Burt, NE1.1100
May 126:14 PM CDTEF0Wayne, NE0.320
May 126:20 PM CDTEF2Burt, NE11.31,1502
May 126:34 PM CDTEF0Wayne, NE0.720
May 127:03 PM CDTEF2Brown, KS1.5500
May 127:11 PM CDTEF1Jackson, KS3.650
May 127:18 PM CDTEF0Brown, KS to NE2.350
May 127:23 PM CDTUnratedBurt, NE0.450
May 127:38 PM CDTUnratedJackson, KS0.010
May 127:43 PM CDTUnratedBurt, NE0.520
May 127:49 PM CDTUnratedJackson, KS0.010

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.