Tornadoes · United States · Oklahoma · 2021

Unrated tornado, Bray to Lake Fuqua Dam, Oklahoma, November 10, 2021

From Bray to Lake Fuqua Dam, this Unrated tornado ran 4.0 miles across Stephens County on November 10, 2021, touching down at 6:35 PM CST and reaching 100 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
November 10, 2021
Touchdown
6:35 PM CST (00:35 UTC)
Lifted
6:48 PM CST (00:48 UTC)
On the ground
13 minutes
Path length
4.0 miles (6.4 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
County
Stephens County
Touchdown point
34.610, -97.760
Lift-off point
34.580, -97.700
Record number
2111101835-01

What the Weather Service recorded

An unseasonably warm and moist airmass in place ahead of a cold front led to numerous thunderstorms developing across Oklahoma into western north Texas during the afternoon and evening of the 10th. Storms initially produced numerous large hail reports, with a couple high wind gusts and a tornado reported as well across southern Oklahoma.

Storm chasers, including off-duty employees from the NWS Weather Decision Training Division, observed a tornado in northeastern Stephens County. The tornado moved through rural areas and no damage was reported to the NWS or local agencies, and the tornado path is estimated.

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 21:29 UTC and running to 02:29 UTC.

Issued (UTC)ExpiredProductOffice
21:29 UTC02:29 UTCSevere Thunderstorm WatchOUN
23:53 UTC00:10 UTCSevere Thunderstorm WarningOUN
00:20 UTC01:00 UTCSevere Thunderstorm WarningOUN
00:40 UTC01:07 UTCTornado 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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:59 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

0.6 hours before the tornado, 76 km from the path. November 11, 2021.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2021-11-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 964 joules per kilogram, CIN -28, lifted condensation level 884 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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 2021-11-11The 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 186 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
964 J/kg
Mixed-layer CIN
-28 J/kg
Surface CAPE
1559 J/kg
Mixed-layer LCL
884 m above ground
0-6 km bulk shear
35 kt
0-1 km bulk shear
23 kt
0-1 km storm-relative helicity
186 m²/s²
0-3 km storm-relative helicity
206 m²/s²
Significant tornado parameter
0.6
Supercell composite
4.4
0-3 km lapse rate
6.2 K/km

Open this sounding in Storm Lab

The surface observations

Halliburton Field Airport/Duncan (DUC), 25 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
22:35 UTC7161180° 11 kt1008.1
22:55 UTC69.861170° 11 kt1008.1
23:15 UTC68.460.6170° 9 kt1008.1
23:35 UTC67.861170° 9 kt1008.1
23:55 UTC66.460.6170° 5 kt1008.1
00:15 UTC66.461.2210° 7 kt1008.5
00:35 UTC67.5610° 0 kt1008.8VCTS
00:55 UTC67.361.2300° 12 kt1009.5
01:15 UTC6960.6300° 9 kt1009.5
01:35 UTC6857.6320° 11 kt1009.5
01:55 UTC6656320° 9 kt1009.8
02:15 UTC64.254.7320° 10 kt1010.2

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

The radar

The Norman radar (KTLX), 92 km away, was scanning. The volume nearest the touchdown began at 00:33 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
23:53 UTCHAIL 13 S Rush SpringsGrady, OK
00:23 UTCHAIL 14 Ne BrayStephens, OKDIMES AND QUARTERS. TIME ESTIMATED BASED ON RADAR.
00:39 UTCTORNADO4 Se BrayStephens, 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 November 10, 2021

3 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
November 107:14 PM CSTEF0Tulsa, OK0.5150$25,000
November 107:26 PM CSTEF0Wagoner, OK0.4100$75,000
November 107:29 PM CSTEF0Rogers, OK0.380

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.