Tornadoes · United States · Oklahoma · 2021

EF0 tornado, Loyal, Oklahoma, May 27, 2021

This EF0 tornado ran 0.1 miles across Kingfisher County on May 27, 2021, touching down at 1:16 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 27, 2021
Touchdown
1:16 PM CDT (18:16 UTC)
Path length
0.1 miles (0.2 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
County
Kingfisher County
Touchdown point
35.972, -98.063
Lift-off point
35.972, -98.063
Record number
2105271216-01

What the Weather Service recorded

Thunderstorms developed during the evening hours of the 16th along a residual outflow boundary near the Red River, producing scattered reports of severe wind and hail, along with one tornado report. Storms continued into the early morning hours of the 17th.

Storm chasers observed a brief tornado 3.2 miles east of Loyal that occurred in a field about 50 yards north of County Road EW720. No damage was observed.

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

The warnings

2 minutes of warning. NWS OUN issued a tornado warning for this county at 18:14 UTC, 2 minutes before the tornado touched down, in force until 19:00 UTC.

The county was under a tornado watch, issued at 16:58 UTC and running to 00:38 UTC.

Issued (UTC)ExpiredProductOffice
16:58 UTC00:38 UTCTornado WatchOUN
17:14 UTC18:00 UTCSevere Thunderstorm WarningOUN
17:29 UTC18:15 UTCSevere Thunderstorm WarningOUN
17:39 UTC20:45 UTCFlood AdvisoryOUN
17:51 UTC18:30 UTCSevere Thunderstorm WarningOUN
17:58 UTC18:45 UTCSevere Thunderstorm WarningOUN
18:00 UTC01:02 UTCFlood WatchOUN
18:14 UTC19:00 UTCTornado WarningOUN
18:29 UTC19:15 UTCSevere Thunderstorm WarningOUN
18:41 UTC22:45 UTCFlash Flood WarningOUN
18:47 UTC19:30 UTCSevere Thunderstorm WarningOUN
19:15 UTC19:44 UTCSevere Thunderstorm WarningOUN
19:51 UTC23:00 UTCFlood AdvisoryOUN
19:51 UTC20:30 UTCSevere Thunderstorm WarningOUN
20:27 UTC20:40 UTCSevere Thunderstorm WarningOUN
20:34 UTC20:59 UTCSevere Thunderstorm WarningOUN
20:39 UTC22:52 UTCFlash Flood WarningOUN
21:03 UTC21:30 UTCSevere Thunderstorm WarningOUN
21:15 UTC22:00 UTCSevere Thunderstorm WarningOUN
21:53 UTC22:30 UTCSevere Thunderstorm WarningOUN
21:56 UTC22:45 UTCSevere Thunderstorm WarningOUN
21:56 UTC00:35 UTCFlood AdvisoryOUN
22:25 UTC01:30 UTCFlash Flood WarningOUN
22:47 UTC00:33 UTCFlash Flood WarningOUN
22:52 UTC23:30 UTCSevere Thunderstorm WarningOUN
01:26 UTC04:30 UTCFlood AdvisoryOUN
01:42 UTC01:39 UTCFlood AdvisoryOUN

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 Enhanced Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 16:10 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

6.3 hours before the tornado, 103 km from the path. May 27, 2021.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z on 2021-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2431 joules per kilogram, CIN -121, lifted condensation level 765 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 12:00Z on 2021-05-27The 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 264 square meters per square second, 0 to 6 km bulk shear 43 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
2431 J/kg
Mixed-layer CIN
-121 J/kg
Surface CAPE
2734 J/kg
Mixed-layer LCL
765 m above ground
0-6 km bulk shear
43 kt
0-1 km bulk shear
22 kt
0-1 km storm-relative helicity
264 m²/s²
0-3 km storm-relative helicity
360 m²/s²
Significant tornado parameter
1.5
Supercell composite
7.5
0-3 km lapse rate
5.3 K/km

Open this sounding in Storm Lab

The radar

The Vance AFB radar (KVNX), 86 km away, was scanning. The volume nearest the touchdown began at 18:15 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
18:30 UTCTSTM WND DMGDoverKingfisher, OKDAMAGE TO A MOBILE HOME.
19:06 UTCTSTM WND GST 70CrescentLogan, OKESTIMATED WIND GUST.
19:15 UTCTSTM WND DMGGuthrieLogan, OKLARGE TREE LIMBS DOWNED OVER ROADWAY.
19:25 UTCFLASH FLOODKingfisherKingfisher, OKROUGHLY A FOOT OF WATER OVER ROADWAYS IN KINGFISHER.
19:36 UTCFLASH FLOOD3 Nw KingfisherKingfisher, OKWATER RUNNING OVER MULTIPLE ROADWAYS.
19:36 UTCHAIL 1.75GuthrieLogan, OKTWITTER PHOTO. TIME IS RADAR ESTIMATE.
19:45 UTCFLASH FLOODKingfisherKingfisher, OKVIDEO OF A CAR STRANDED IN ONE TO TWO FEET OF WATER NEAR CENTER OF TOWN.
20:18 UTCHAIL 1.755 S RingwoodMajor, OKFROM NWSCHAT.

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 May 27, 2021

5 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 2711:51 AM CDTEF1Polk, MO0.150$300,000
May 2712:08 PM CDTEF1Polk, MO1.250$75,000
May 273:29 PM CDTUnratedClay, IL0.210
May 273:43 PM CDTEF0Clay, IL2.850$45,000
May 277:13 PM CDTEF1McIntosh, OK3.0500$25,000

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.