Tornadoes · United States · Oklahoma · 2017

EF2 tornado, LeFlore County, Oklahoma, April 28, 2017

This EF2 tornado ran 8.1 miles across LeFlore County on April 28, 2017, touching down at 10:36 PM CDT and reaching 750 yards wide. It killed nobody, and did $150,000 of property damage.

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 mphthis tornado

    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
EF2
Date
April 28, 2017
Touchdown
10:36 PM CDT (03:36 UTC)
Lifted
10:51 PM CDT (03:51 UTC)
On the ground
15 minutes
Path length
8.1 miles (13.0 km)
Path width
750 yards (686 m)
Deaths
0
Injuries
0
Property damage
$150,000
County
LeFlore County
Touchdown point
35.102, -94.578
Lift-off point
35.215, -94.551
Record number
1704282136-01

The damage survey

38 damage points were recorded along this path by NWS TSA, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 115 mph.

  • 3 poles snapped from here to w
  • multiple vehicles moved/rolled, bulldozer moved, dump truck rolled
  • 8800 lb conex container moved 50 yards
  • two conex containers moved up to 50 yards, school bus rolled, tractors moved/rolled

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

The warnings

11 minutes of warning. NWS TSA issued a tornado warning for this county at 03:25 UTC, 11 minutes before the tornado touched down, in force until 04:00 UTC.

The county was under a severe thunderstorm watch, issued at 03:02 UTC and running to 08:49 UTC.

Issued (UTC)ExpiredProductOffice
00:00 UTC09:16 UTCFlash Flood WatchTSA
03:00 UTC03:45 UTCSevere Thunderstorm WarningTSA
03:02 UTC08:49 UTCSevere Thunderstorm WatchTSA
03:25 UTC04:00 UTCTornado WarningTSA
03:58 UTC04:20 UTCTornado WarningTSA
17:36 UTC23:30 UTCFlash Flood WarningTSA

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 00:51 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.

Springfield, MO (KSGF), 00:00Z

3.6 hours before the tornado, 205 km from the path. April 29, 2017.

Skew-T log-pSkew-T log-p diagram, Springfield, MO at 00:00Z on 2017-04-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 65 joules per kilogram, CIN -331, lifted condensation level 506 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, Springfield, MO at 00:00Z on 2017-04-29The 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 55 square meters per square second, 0 to 6 km bulk shear 74 knots.1939587897Sfc1 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
65 J/kg
Mixed-layer CIN
-331 J/kg
Surface CAPE
122 J/kg
Mixed-layer LCL
506 m above ground
0-6 km bulk shear
74 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.9 K/km

Open this sounding in Storm Lab

Springfield, MO (KSGF), 12:00Z

8.4 hours after it, 205 km from the path. April 29, 2017.

Skew-T log-pSkew-T log-p diagram, Springfield, MO at 12:00Z on 2017-04-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -77850, lifted condensation level 704 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Springfield, MO at 12:00Z on 2017-04-29The 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 318 square meters per square second, 0 to 6 km bulk shear 72 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
0 J/kg
Mixed-layer CIN
-77850 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
704 m above ground
0-6 km bulk shear
72 kt
0-1 km bulk shear
29 kt
0-1 km storm-relative helicity
318 m²/s²
0-3 km storm-relative helicity
413 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.6
0-3 km lapse rate
3.6 K/km

Open this sounding in Storm Lab

The surface observations

Robert S Kerr Airport/Poteau (RKR), 16 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
01:55 UTC71.8680° 0 kt1005.4
02:15 UTC71680° 0 kt1005.8
02:35 UTC71.2680° 0 kt1005.4
02:55 UTC71.86830° 4 kt1004.7TS
03:15 UTC7168.530° 8 kt1003.7-TSRA
03:35 UTC73.869.3170° 8 kt251005.4TS
03:55 UTC74.370.2190° 9 kt1004.7VCTS
04:15 UTC7470.20° 0 kt1004.1VCTS
04:35 UTC72.770.310° 4 kt1003.7
04:55 UTC71.269.8340° 5 kt1003.7BR
05:15 UTC72.3700° 0 kt1003.4
05:35 UTC75.471140° 11 kt141003.4

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

The radar

The Western Arkansas radar (KSRX), 24 km away, was scanning. The volume nearest the touchdown began at 03:36 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
03:41 UTCTORNADO4 Nw CameronLe Flore, OKDOPPLER RADAR INDICATED TORNADIC DEBRIS SIGNATURE FOR SEVERAL MINUTES. EMERGENCY MANAGEMENT CONDUCTED PRELIMINARY SURVEY. NWS SURVEY WILL BE CONDUCTED TODAY.
03:41 UTCTORNADO4 Nw CameronLe Flore, OKA TORNADO DESTROYED MOBILE HOMES...DAMAGED HOMES...DESTROYED OUTBUILDINGS...SNAPPED NUMEROUS TREES AND POWER POLES...UPROOTED NUMEROUS TRESS...AND ROLLED SEVERAL VEHICLES. BASED ON THIS DAMAGE...ESTIMATED MAXIMUM WIND WA
03:45 UTCHAIL 2.75PocolaLe Flore, OK
03:49 UTCHAIL 1.75PoteauLe Flore, OK
03:50 UTCHAIL 1PanamaLe Flore, OKNEAR HIGHWAY 271
03:50 UTCHAIL 1.75ArkomaLe Flore, OK
03:55 UTCTSTM WND DMG1 W CameronLe Flore, OKTREES AND POWER LINES DOWN WEST OF CAMERON.
04:05 UTCHAIL 0.75ArkomaLe Flore, OK
04:15 UTCTSTM WND DMG1 W CameronLe Flore, OKDAMAGE TO A MOBILE HOME WEST OF CAMERON.
04:15 UTCHAIL 0.75MoffettSequoyah, OK

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

This ground now

The live radar over the trackEvery 2017 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

The other tornadoes of April 28, 2017

1 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 2811:53 PM EDTEF1Oldham, KY1.3250$200,000

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.