Tornadoes · United States · Oklahoma · 2015

EF0 tornado, Moorewood, Oklahoma, April 8, 2015

This EF0 tornado ran 0.2 miles across Custer County on April 8, 2015, touching down at 8:58 PM CDT and reaching 30 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
April 8, 2015
Touchdown
8:58 PM CDT (01:58 UTC)
Path length
0.2 miles (0.3 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
County
Custer County
Touchdown point
35.653, -99.312
Lift-off point
35.653, -99.312
Record number
1504081958-01

What the Weather Service recorded

A warm front/dryline triple point was present across far northwestern Oklahoma during the daylight hours. As a weak shortwave moved across the Southern Plains, strong flow aloft overspread the region. Daytime heating and the influence of the upper wave lifted the cap, allowing for scattered severe thunderstorm development.

Spotters reported a brief tornado touchdown about 4 miles northeast of Hammon. No damage is known to have occurred with this tornado.

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

The warnings

0 minutes of warning. NWS OUN issued a tornado warning for this county at 01:58 UTC, 0 minutes before the tornado touched down, in force until 02:45 UTC.

The county was under a tornado watch, issued at 20:37 UTC and running to 04:02 UTC.

Issued (UTC)ExpiredProductOffice
18:00 UTC09:43 UTCFire Weather WatchOUN
20:37 UTC04:02 UTCTornado WatchOUN
21:46 UTC22:09 UTCSevere Thunderstorm WarningOUN
01:11 UTC02:00 UTCSevere Thunderstorm WarningOUN
01:53 UTC02:45 UTCSevere Thunderstorm WarningOUN
01:58 UTC02:45 UTCTornado WarningOUN
02:42 UTC03:12 UTCSevere Thunderstorm 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 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 00:58 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

2.0 hours before the tornado, 180 km from the path. April 9, 2015.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2015-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 427 joules per kilogram, CIN -258, lifted condensation level 1139 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 2015-04-09The 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 251 square meters per square second, 0 to 6 km bulk shear 51 knots.19395878Sfc1 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
427 J/kg
Mixed-layer CIN
-258 J/kg
Surface CAPE
2148 J/kg
Mixed-layer LCL
1139 m above ground
0-6 km bulk shear
51 kt
0-1 km bulk shear
33 kt
0-1 km storm-relative helicity
251 m²/s²
0-3 km storm-relative helicity
302 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3
0-3 km lapse rate
5.9 K/km

Open this sounding in Storm Lab

Norman, OK (KOUN), 12:00Z

10.0 hours after it, 180 km from the path. April 9, 2015.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z on 2015-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1639 joules per kilogram, CIN -44, lifted condensation level 600 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 2015-04-09The 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 396 square meters per square second, 0 to 6 km bulk shear 34 knots.19395878Sfc1 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
1639 J/kg
Mixed-layer CIN
-44 J/kg
Surface CAPE
2322 J/kg
Mixed-layer LCL
600 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
46 kt
0-1 km storm-relative helicity
396 m²/s²
0-3 km storm-relative helicity
520 m²/s²
Significant tornado parameter
3.4
Supercell composite
21.8
0-3 km lapse rate
5.2 K/km

Open this sounding in Storm Lab

The surface observations

Elk City (ELK), 26 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
00:15 UTC71.660.8170° 14 kt261004.4
00:35 UTC71.660.8170° 16 kt271004.1
00:55 UTC71.659160° 16 kt211004.1
01:15 UTC71.660.8150° 12 kt221004.1
01:35 UTC71.659150° 19 kt261004.1VCTS
01:55 UTC69.859170° 13 kt261004.4VCTS
02:15 UTC69.85950° 4 kt161006.1TS
02:35 UTC69.860.8160° 7 kt1006.1VCTS
02:55 UTC6860.8140° 14 kt191005.4
03:15 UTC6860.8150° 12 kt201006.1
03:35 UTC6862.6170° 9 kt1006.1
03:55 UTC6862.6170° 11 kt151005.8

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

The radar

The Altus AFB radar (KFDR), 147 km away, was scanning. The volume nearest the touchdown began at 01:59 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
23:20 UTCHAIL 17 Ne CamargoDewey, OK
23:50 UTCHAIL 11 E CestosDewey, OK
00:47 UTCHAIL 11 N SweetwaterRoger Mills, OK
01:05 UTCHAIL 2.75DempseyRoger Mills, OKREPORTS OF BROKEN CAR WINDOWS.
01:05 UTCHAIL 2.75DempseyRoger Mills, OK
01:07 UTCTSTM WND GST 707 Ne SweetwaterRoger Mills, OK3 N OF GRIMES
01:20 UTCTSTM WND GST 757 Se CheyenneRoger Mills, OK
01:21 UTCHAIL 1.5CheyenneRoger Mills, OK
01:25 UTCHAIL 24 S CheyenneRoger Mills, OK
01:27 UTCTSTM WND GST 755 E CheyenneRoger Mills, OK
01:27 UTCHAIL 35 E CheyenneRoger Mills, OK
01:40 UTCHAIL 32 N HammonRoger Mills, OK
01:54 UTCHAIL 1.752 E HammonCuster, OK
01:56 UTCHAIL 13 N HammonRoger Mills, OK
02:02 UTCTORNADO4 Ne HammonCuster, OKBRIEF TORNADO
02:36 UTCHAIL 1.54 S PutnamCuster, OK
02:45 UTCTSTM WND GST 658 Nw ThomasDewey, OK
02:45 UTCHAIL 1.758 Nw ThomasDewey, OK
02:55 UTCHAIL 1.755 Sw OakwoodDewey, 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 April 8, 2015

6 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 83:30 PM CDTEF1Washington, MO4.1300
April 86:24 PM CDTEF0Comanche, KS1.975
April 86:49 PM CDTEF0Barber, KS16.2250
April 88:15 PM CDTEF0Barber, KS0.650
April 88:32 PM CDTEF0Sedgwick, KS3.175
April 88:43 PM CDTEF0Kingman, KS0.775

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.