Tornadoes · United States · Oklahoma · 2018

EF0 tornado, Davis to Wynnewood, Oklahoma, October 7, 2018

From Davis to Wynnewood, this EF0 tornado ran 1.0 miles across Murray and Garvin counties on October 7, 2018, touching down at 5:38 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
October 7, 2018
Touchdown
5:38 PM CDT (22:38 UTC)
Lifted
5:39 PM CDT (22:39 UTC)
On the ground
1 minutes
Path length
1.0 miles (1.6 km)
Path width
20 yards (18 m)
Deaths
0
Injuries
0
Counties
Murray and Garvin counties
Touchdown point
34.501, -97.166
Lift-off point
34.501, -97.166
Record number
1810071638-01

What the Weather Service recorded

A warm front lifted north through Oklahoma during the day on the 7th, producing numerous thunderstorms.

Numerous storm chasers and storm spotters observed a relatively weak tornado that formed just east of Interstate 35 west of Davis. The tornado moved northeast crossing State Highway 7 into Garvin County near NS328 Road. Other than some tree limb damage, no other damage was reported.

A tornado was observed touching down in Murray County west of Davis, then moving northeast crossing into Garvin County near NS328 Road. The tornado moved northeast for less than one-half mile before dissipating. No damage was observed except for a few tree limbs.

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

The warnings

32 minutes of warning. NWS OUN issued a tornado warning for this county at 22:06 UTC, 32 minutes before the tornado touched down, in force until 22:45 UTC.

Issued (UTC)ExpiredProductOffice
06:00 UTC09:00 UTCFlood AdvisoryOUN
09:33 UTC13:30 UTCFlash Flood WarningOUN
21:30 UTC19:29 UTCFlood WatchOUN
21:46 UTC22:30 UTCSevere Thunderstorm WarningOUN
22:06 UTC22:45 UTCTornado WarningOUN
22:15 UTC00:15 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 Marginal Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:57 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

10.6 hours before the tornado, 83 km from the path. October 7, 2018.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z on 2018-10-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1 joules per kilogram, CIN -299, lifted condensation level 690 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 12:00Z on 2018-10-07The 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 39 square meters per square second, 0 to 6 km bulk shear 31 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
1 J/kg
Mixed-layer CIN
-299 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
690 m above ground
0-6 km bulk shear
31 kt
0-1 km bulk shear
18 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.6 K/km

Open this sounding in Storm Lab

Norman, OK (KOUN), 00:00Z

1.4 hours after it, 83 km from the path. October 8, 2018.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2018-10-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 864 joules per kilogram, CIN -52, lifted condensation level 889 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 2018-10-08The 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 234 square meters per square second, 0 to 6 km bulk shear 37 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
864 J/kg
Mixed-layer CIN
-52 J/kg
Surface CAPE
2670 J/kg
Mixed-layer LCL
889 m above ground
0-6 km bulk shear
37 kt
0-1 km bulk shear
27 kt
0-1 km storm-relative helicity
234 m²/s²
0-3 km storm-relative helicity
274 m²/s²
Significant tornado parameter
0.8
Supercell composite
11.1
0-3 km lapse rate
5.9 K/km

Open this sounding in Storm Lab

The surface observations

Pauls Valley Municipal Airport (PVJ), 24 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:55 UTC77.271.8140° 6 kt1011.5
21:15 UTC77.472140° 7 kt1011.5
21:35 UTC77.272140° 7 kt1011.5
21:55 UTC77.471.8130° 6 kt1011.2
22:15 UTC76.572140° 5 kt1011.2-RA
22:35 UTC75.272.5140° 5 kt1011.2TS
22:55 UTC75.773140° 6 kt1011.2-RA
23:15 UTC7672.5140° 6 kt1011.2
23:35 UTC7672.7130° 4 kt1011.2
23:55 UTC75.472.7120° 4 kt1011.2
00:15 UTC74.872.7110° 5 kt1011.2
00:35 UTC75.272120° 8 kt1011.5

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

The radar

The Norman radar (KTLX), 93 km away, was scanning. The volume nearest the touchdown began at 22:37 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
22:38 UTCTORNADO2 Nw DavisMurray, OK

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

This ground now

The live radar over the trackEvery 2018 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

The other tornadoes of October 7, 2018

4 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
October 72:31 PM CDTUnratedCastro, TX8.7200
October 74:22 PM CDTEF0Kiowa, OK0.110
October 75:10 PM CDTEF0Kiowa, OK0.110
October 77:46 PM CDTEF0Osage, OK1.5225$50,000

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.