Tornadoes · United States · Oklahoma · 2023

EF0 tornado, Chickasha Arpt, Oklahoma, May 13, 2023

This EF0 tornado ran 0.1 miles across Grady County on May 13, 2023, touching down at 3:18 PM CDT and reaching 20 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 13, 2023
Touchdown
3:18 PM CDT (20:18 UTC)
Path length
0.1 miles (0.2 km)
Path width
20 yards (18 m)
Deaths
0
Injuries
0
County
Grady County
Touchdown point
35.057, -97.979
Lift-off point
35.057, -97.979
Record number
2305131418-01

The damage survey

8 damage points were recorded along this path by NWS OUN, in the Damage Assessment Toolkit the survey teams carry. The highest wind the damage implies is 96 mph.

  • from EM. Tin from somewhere wrapped around sign. Wrapped around sign from south.
  • Likely source of tin farther north. Photo from EM may be this barn collapsed.
  • EM decription: roof damage
  • EM description: broken windows, porch pillars, and barn

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

Some severe and flood hazard, associated with convection from the 12th, lingered into the early morning hours of the 13th. By the afternoon, a few scattered storms developed in the vicinity of a remnant mesoscale convective vortex (MCV) as it translated across southwest into north-central Oklahoma. This convection produced a few reports of wind damage, large hail, and a brief (weak) tornado across portions of central Oklahoma.

Storm chasers observed a tornado estimated to have been just south of the Chickasha airport. No damage is known to have occurred.

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.

Issued (UTC)ExpiredProductOffice
03:39 UTC07:00 UTCSevere Thunderstorm WatchOUN
19:55 UTC20:45 UTCSevere Thunderstorm WarningOUN
20:33 UTC22:30 UTCFlood AdvisoryOUN
20:38 UTC21:30 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, with a 0.02 chance of a tornado within 25 miles. 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.

Norman, OK (KOUN), 12:00Z

8.3 hours before the tornado, 56 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

Norman, OK (KOUN), 00:00Z

3.7 hours after it, 56 km from the path. May 14, 2023.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2023-05-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 364 joules per kilogram, CIN -39, lifted condensation level 1102 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 2023-05-14The 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 -7 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
364 J/kg
Mixed-layer CIN
-39 J/kg
Surface CAPE
1336 J/kg
Mixed-layer LCL
1102 m above ground
0-6 km bulk shear
35 kt
0-1 km bulk shear
14 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
75 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.1
0-3 km lapse rate
7.0 K/km

Open this sounding in Storm Lab

The radar

The Norman radar (KTLX), 71 km away, was scanning. The volume nearest the touchdown began at 20:19 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
21:45 UTCTSTM WND GST 661 Nw BethanyOklahoma, OKPWA.

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 13, 2023

20 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 134:06 AM CDTEF1Cameron, TX0.5200111$500,000
May 131:21 PM CDTUnratedBuena Vista, IA0.010
May 131:22 PM CDTEF0Warren, IA1.140$2,000
May 131:36 PM CDTUnratedSac, IA0.330
May 131:50 PM CDTUnratedBuena Vista, IA1.075
May 131:16 PM MDTUnratedMcKinley, NM0.520
May 132:37 PM CDTUnratedMacon, IL0.510
May 133:23 PM CDTUnratedMarion, IA0.530
May 133:29 PM CDTEF0Marion, IA0.550$10,000
May 133:52 PM CDTEF0Marion, IA0.740$1,000
May 134:15 PM CDTUnratedPocahontas, IA1.230
May 134:17 PM CDTEF0Buena Vista, IA2.075
May 134:51 PM CDTUnratedCalhoun, IA0.630
May 135:18 PM CDTUnratedGreene, IA0.440
May 136:20 PM CDTUnratedMarion, IA0.330
May 136:22 PM CDTEF0Calhoun, IA1.450$20,000
May 136:26 PM CDTUnratedPocahontas, IA0.540
May 136:52 PM CDTUnratedPocahontas, IA0.530
May 136:52 PM CDTEF0Marion, IA0.950$2,000
May 137:22 PM CDTUnratedPocahontas, IA0.630

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.