Tornadoes · United States · Oklahoma · 2021

Unrated tornado, Anadarko to Chickasha Arpt, Oklahoma, October 10, 2021

From Anadarko to Chickasha Arpt, this Unrated tornado ran 1.8 miles across Grady and Caddo counties on October 10, 2021, touching down at 7:02 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
October 10, 2021
Touchdown
7:02 PM CDT (00:02 UTC)
Lifted
7:05 PM CDT (00:05 UTC)
On the ground
3 minutes
Path length
1.8 miles (2.9 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Counties
Grady and Caddo counties
Touchdown point
35.055, -98.112
Lift-off point
35.067, -98.083
Record number
2110101802-01

The damage survey

12 damage points were recorded along this path by NWS OUN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 110 mph.

  • Old building lost brick facade.
  • Fencing and some building damage.
  • EM report of damage to hangars at Anadarko airport.
  • from EM. Unsure of DOD. Approx location.

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 unseasonably warm and moist airmass was in place across the region ahead of a powerful upper wave moving out of the 4 corners region. This led to the development of numerous severe thunderstorms across Oklahoma and Texas during the afternoon and evening of the 10th. Several tornadoes were reported, along with hail larger than baseballs that impacted Norman, OK for the second time in six months, leading to millions of dollars in damages once again to homes, cars, and businesses.

Storm chasers initially observed a tornado develop southwest of Anadarko and move east-northeast. Damage was reported to a hangar at the Anadarko airport just south of town. The most significant damage was about 5 miles east of Anadarko where a roof was removed from a home. Although the tornado itself passed just south of Anadarko, the storm produced widespread wind damage within the town of Anadarko (see separate entry).

Storm chasers observed a tornado that developed about 3 miles southwest of Verden and moved east-northeast, crossing into Grady County about 1.5 miles south of Verden. No damage was reported along the path of this tornado and the path was estimated.

Storm chasers observed a tornado which initially developed in Caddo County approximately 3 miles southwest of Verden and moved east-northeast crossing into Grady County about 1.5 mile south of Verden and to a point approximately 1 mile south-southeast of Verden. The tornado path was estimated as no damage was reported along the tornado path. Despite no known damage from the tornado, the storm did produce wind damage in and north of the town of Verden (see separate entry for this wind damage).

A storm chaser observed a tornado estimated to be approximately 3 miles north of Chickasha. No damage was reported in the immediate area of the tornado, although the storm was producing wind damage about three miles farther north.

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

The warnings

9 minutes of warning. NWS OUN issued a tornado warning for this county at 23:53 UTC, 9 minutes before the tornado touched down, in force until 00:16 UTC.

The county was under a tornado watch, issued at 20:22 UTC and running to 01:26 UTC.

Issued (UTC)ExpiredProductOffice
20:22 UTC01:26 UTCTornado WatchOUN
23:05 UTC00:00 UTCSevere Thunderstorm WarningOUN
23:14 UTC00:00 UTCTornado WarningOUN
23:29 UTC02:30 UTCFlood AdvisoryOUN
23:53 UTC00:16 UTCTornado WarningOUN
23:57 UTC00:45 UTCSevere Thunderstorm WarningOUN
00:25 UTC02:12 UTCFlash Flood 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 Moderate Risk, with a 0.15 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 19:50 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

0.0 hours before the tornado, 66 km from the path. October 11, 2021.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2021-10-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1436 joules per kilogram, CIN -35, lifted condensation level 1199 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 2021-10-11The 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 187 square meters per square second, 0 to 6 km bulk shear 71 knots.1939587897117136Sfc1 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
1436 J/kg
Mixed-layer CIN
-35 J/kg
Surface CAPE
1752 J/kg
Mixed-layer LCL
1199 m above ground
0-6 km bulk shear
71 kt
0-1 km bulk shear
20 kt
0-1 km storm-relative helicity
187 m²/s²
0-3 km storm-relative helicity
255 m²/s²
Significant tornado parameter
1.9
Supercell composite
8.8
0-3 km lapse rate
6.2 K/km

Open this sounding in Storm Lab

The surface observations

Chickasha Municipal Airport (CHK), 13 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
22:15 UTC83.765.5150° 9 kt1001
22:35 UTC84.266140° 12 kt171000
22:55 UTC8365.8120° 14 kt18998
23:15 UTC8266.2110° 12 kt997.6
23:35 UTC81.366.6110° 12 kt997.3VCTS
23:55 UTC80.866.790° 18 kt23994.9VCTS
00:15 UTC65.559.5310° 43 kt71998+TSRA
00:35 UTC6261.2360° 28 kt52999.3+TSRA BR
00:55 UTC60.860360° 19 kt241001+TSRA BR
01:15 UTC60.459.7350° 15 kt1001.4VCTSRA BR
01:35 UTC60.359.5330° 13 kt1002.4RA BR
01:55 UTC6059.4330° 16 kt1001.7

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

The radar

The Norman radar (KTLX), 80 km away, was scanning. The volume nearest the touchdown began at 00:02 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
23:13 UTCTORNADO9 E CoopertonKiowa, OKA TORNADO WAS OBSERVED NEAR SADDLE MOUNTAIN.
23:20 UTCTORNADO8 W BooneCaddo, OKMULTIPLE REPORTS OF AN OBSERVED TORNADO AND DAMAGE W OF BOONE AND SOUTH OF CARNEGIE/ALDEN NEAR STATE HIGHWAYS 58 AND 19.
23:36 UTCTSTM WND DMG7 Nw ApacheCaddo, OKMANY POWER POLES DOWNED.
23:40 UTCTSTM WND DMG5 Nnw ApacheCaddo, OKTREES DOWNED AND OUTBUILDINGS DAMAGED BY ESTIMATED 70 TO 80 MPH WINDS IN STORM REAR FLANK DOWNDRAFT.
23:45 UTCTORNADO4 Ssw AnadarkoCaddo, OK
00:00 UTCTSTM WND GST 624 Ene ApacheCaddo, OK
00:00 UTCTSTM WND GST 823 Nw ChickashaGrady, OK
00:02 UTCTORNADO2 S VerdenGrady, OK
00:13 UTCTSTM WND DMG4 Sse ChickashaGrady, OKTREE DAMAGE.
00:15 UTCTSTM WND GST 582 Sse ChickashaGrady, OK
00:15 UTCTSTM WND GST 704 Sw El RenoCanadian, OK
00:30 UTCTSTM WND DMGYukonCanadian, OKLARGE TREES BLOWN DOWN.
00:35 UTCTSTM WND GST 603 Nw ChickashaGrady, OK
00:40 UTCHAIL 1.52 Wnw DibbleMcclain, OK
00:40 UTCHAIL 1.754 Ne BlanchardMcclain, OK
00:48 UTCHAIL 1NewcastleMcclain, OKAT US-62 AND FOX LANE.
00:51 UTCHAIL 1GoldsbyMcclain, OK
00:57 UTCHAIL 1.753 Se GoldsbyMcclain, OK
01:05 UTCHAIL 22 Nw NormanCleveland, OK

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2021 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

The other tornadoes of October 10, 2021

18 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
October 105:59 PM CDTUnratedKiowa, OK0.120
October 106:10 PM CDTEF2Cook, MN4.0500
October 106:13 PM CDTEF1Kiowa, OK2.9200$30,000
October 106:20 PM CDTEF1Caddo, OK4.450$40,000
October 106:45 PM CDTEF2Caddo, OK8.1100$60,000
October 107:16 PM CDTUnratedGrady, OK0.250
October 108:21 PM CDTEF0Oklahoma, OK3.3250$20,000
October 108:41 PM CDTEF0Lincoln, OK1.130$5,000
October 108:41 PM CDTEF0Pottawatomie, OK1.650$10,000
October 108:54 PM CDTEF0Pottawatomie, OK1.650
October 109:26 PM CDTEF1Okfuskee, OK2.7300$150,000
October 109:26 PM CDTEF1Pontotoc, OK7.3300$100,000
October 109:42 PM CDTUnratedCreek, OK1.0100
October 1010:05 PM CDTEF0Okmulgee, OK2.2300$10,000
October 1010:30 PM CDTUnratedTulsa, OK0.7100
October 1010:45 PM CDTEF1Wagoner, OK3.4700$3.0 million
October 1011:30 PM CDTEF1Muskogee, OK13.7900$65,000
October 1012:10 AM CDTEF1Delaware, OK5.9200

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.