Tornadoes · United States · Oklahoma · 2015

EF0 tornado, Byars, Oklahoma, December 26, 2015

This EF0 tornado ran 0.1 miles across McClain County on December 26, 2015, touching down at 1:57 PM CST 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
December 26, 2015
Touchdown
1:57 PM CST (19:57 UTC)
Path length
0.1 miles (0.2 km)
Path width
20 yards (18 m)
Deaths
0
Injuries
0
County
McClain County
Touchdown point
34.940, -96.960
Lift-off point
34.940, -96.960
Record number
1512261357-01

What the Weather Service recorded

With abundant moisture in place and strong cold front moving south on the 26th, numerous storms developed across the central and southern parts of Oklahoma and parts of western north Texas. Several of these storms became severe, a few became tornadic, and heavy rains caused some flash flooding.

A brief weak tornado was reported.

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

The warnings

30 minutes of warning. NWS OUN issued a tornado warning for this county at 19:27 UTC, 30 minutes before the tornado touched down, in force until 20:00 UTC.

Issued (UTC)ExpiredProductOffice
06:00 UTC12:00 UTCFlash Flood WatchOUN
17:11 UTC18:00 UTCSevere Thunderstorm WarningOUN
18:22 UTC21:15 UTCFlash Flood WarningOUN
19:27 UTC20:00 UTCTornado WarningOUN
19:55 UTC20:05 UTCTornado WarningOUN
23:08 UTC23:45 UTCFlood AdvisoryOUN
00:00 UTC22:31 UTCWinter Storm WatchOUN
00:00 UTC15:22 UTCWinter Storm 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 16:31 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

8.0 hours before the tornado, 51 km from the path. December 26, 2015.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z on 2015-12-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 608 joules per kilogram, CIN -27, lifted condensation level 537 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 2015-12-26The 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 276 square meters per square second, 0 to 6 km bulk shear 66 knots.1939587897117Sfc1 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
608 J/kg
Mixed-layer CIN
-27 J/kg
Surface CAPE
384 J/kg
Mixed-layer LCL
537 m above ground
0-6 km bulk shear
66 kt
0-1 km bulk shear
33 kt
0-1 km storm-relative helicity
276 m²/s²
0-3 km storm-relative helicity
313 m²/s²
Significant tornado parameter
1.0
Supercell composite
5.4
0-3 km lapse rate
5.5 K/km

Open this sounding in Storm Lab

Norman, OK (KOUN), 00:00Z

4.0 hours after it, 51 km from the path. December 27, 2015.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2015-12-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 7 joules per kilogram, CIN 0, lifted condensation level 433 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 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 2015-12-27The 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 298 square meters per square second, 0 to 6 km bulk shear 77 knots.1939587897117Sfc1 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
7 J/kg
Mixed-layer CIN
0 J/kg
Surface CAPE
9 J/kg
Mixed-layer LCL
433 m above ground
0-6 km bulk shear
77 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
298 m²/s²
0-3 km storm-relative helicity
416 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4
0-3 km lapse rate
1.2 K/km

Open this sounding in Storm Lab

The surface observations

Ada_municipal_airport (ADH), 30 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
18:15 UTC64.464.4170° 10 kt201007.5-TSRA
18:35 UTC64.464.4150° 9 kt1007.1VCTS
18:55 UTC64.464.4150° 9 kt1006.4
19:15 UTC64.464.4150° 7 kt1005.8VCTS BR
19:35 UTC64.464.4160° 3 kt1005.4+VCTSRA
19:55 UTC66.266.2150° 8 kt1005.1VCTS BR
20:15 UTC6868160° 9 kt1005.1-VCTSRA
20:35 UTC69.868190° 10 kt1005.1TS
20:55 UTC69.868190° 8 kt1005.1-VCTSRA
21:15 UTC69.868190° 8 kt1004.7-VCTSRA
21:35 UTC6868190° 11 kt221004.4+TSRA
21:55 UTC6864.4230° 10 kt161004.7-VCTSRA

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

The radar

The Norman radar (KTLX), 52 km away, was scanning. The volume nearest the touchdown began at 19:54 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
18:37 UTCFLASH FLOODNormanCleveland, OK6 TO 12 INCHES OF WATER REPORTED AT HIGHWAY 35NB AND HIGHWAY 9 EXIT.
19:57 UTCTORNADO7 Ne ByarsMcclain, OK

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

This ground now

The live radar over the trackEvery 2015 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

The other tornadoes of December 26, 2015

12 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
December 262:03 PM CSTEF0Hill, TX2.850
December 262:44 PM CSTEF0Henderson, TX0.940
December 263:38 PM CSTEF0Rains, TX0.775
December 265:10 PM CSTEF0Hill, TX1.680
December 265:33 PM CSTEF0Hopkins, TX0.425
December 265:43 PM CSTEF0Ellis, TX1.650
December 266:01 PM CSTEF3Ellis, TX8.512546$9.7 million
December 266:46 PM CSTEF4Garland–Rowlett tornado, TX13.055010468$27 million
December 267:00 PM CSTEF0Ellis, TX5.1150$40,000
December 267:09 PM CSTEF2Collin, TX5.33002119$1.4 million
December 267:17 PM CSTEF1Collin, TX4.5300$1.5 million
December 267:33 PM CSTEF1Collin, TX5.210012$600,000

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.