Tornadoes · United States · Kansas · 2018

EF0 tornado, Maple City to Dexter, Kansas, May 14, 2018

From Maple City to Dexter, this EF0 tornado ran 2.1 miles across Cowley County on May 14, 2018, touching down at 9:26 PM CDT and reaching 50 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 14, 2018
Touchdown
9:26 PM CDT (02:26 UTC)
Lifted
9:35 PM CDT (02:35 UTC)
On the ground
9 minutes
Path length
2.1 miles (3.4 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Cowley County
Touchdown point
37.041, -96.752
Lift-off point
37.071, -96.754
Record number
1805142026-01

The damage survey

21 damage points were recorded along this path by NWS ICT, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 120 mph.

  • tornado lifted in a field.
  • Touched down in open field.
  • Touched down in open country.
  • Tornado lifted in open field.

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

What the Weather Service recorded

Severe thunderstorms developed along and ahead of a quasi-stationary front that was draped across the area. One long-lived supercell produced a brief tornado northwest of Ark City before exiting into Oklahoma and becoming stationary. The supercell then moved north and produced multiple tornadoes as a large bow echo thunderstorm merged with the supercell in central Cowley County. This was quickly followed by several shorter-lived Quasi-Linear Convective System (QLCS) tornadoes north and east of Winfield.

Large electrical transmission lines were downed and a tree was completely uprooted.

Several large trees sustained damage along the path. It also caused damage to a barn.

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

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

The county was under a severe thunderstorm watch, issued at 18:22 UTC and running to 05:00 UTC.

Issued (UTC)ExpiredProductOffice
18:22 UTC05:00 UTCSevere Thunderstorm WatchICT
22:18 UTC23:15 UTCSevere Thunderstorm WarningICT
23:12 UTC00:00 UTCTornado WarningICT
23:37 UTC00:30 UTCTornado WarningICT
00:27 UTC01:00 UTCSevere Thunderstorm WarningICT
00:30 UTC01:15 UTCSevere Thunderstorm WarningICT
01:18 UTC01:45 UTCSevere Thunderstorm WarningICT
01:55 UTC03:00 UTCSevere Thunderstorm WarningICT
02:26 UTC03:30 UTCSevere Thunderstorm WarningICT
02:28 UTC03:30 UTCSevere Thunderstorm WarningICT
02:44 UTC03:15 UTCTornado WarningICT
02:56 UTC03:14 UTCTornado WarningICT
03:08 UTC04:15 UTCSevere Thunderstorm WarningICT
03:16 UTC03:34 UTCTornado WarningICT
03:31 UTC04:00 UTCSevere Thunderstorm WarningICT
05:15 UTC07:46 UTCFlood WarningICT

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 01:02 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

2.4 hours before the tornado, 212 km from the path. May 15, 2018.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2018-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2133 joules per kilogram, CIN -89, lifted condensation level 1290 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 2018-05-15The 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 42 square meters per square second, 0 to 6 km bulk shear 26 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
2133 J/kg
Mixed-layer CIN
-89 J/kg
Surface CAPE
2073 J/kg
Mixed-layer LCL
1290 m above ground
0-6 km bulk shear
26 kt
0-1 km bulk shear
6 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.1
0-3 km lapse rate
6.9 K/km

Open this sounding in Storm Lab

Norman, OK (KOUN), 12:00Z

9.6 hours after it, 212 km from the path. May 15, 2018.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z on 2018-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 31 joules per kilogram, CIN -367, lifted condensation level 1479 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 2018-05-15The 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 36 square meters per square second, 0 to 6 km bulk shear 21 knots.1939Sfc1 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
31 J/kg
Mixed-layer CIN
-367 J/kg
Surface CAPE
120 J/kg
Mixed-layer LCL
1479 m above ground
0-6 km bulk shear
21 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
223 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2
0-3 km lapse rate
5.2 K/km

Open this sounding in Storm Lab

The radar

The Wichita radar (KICT), 90 km away, was scanning. The volume nearest the touchdown began at 02:23 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
23:26 UTCHAIL 0.75WinfieldCowley, KSVIA SOCIAL MEDIA.
23:34 UTCFUNNEL CLOUD3 Ne Geuda SpringsCowley, KS
23:35 UTCTORNADO4 Ne Geuda SpringsCowley, KS
23:40 UTCTORNADO2 Nw Arkansas CityCowley, KS
23:47 UTCHAIL 1.52 N Arkansas CityCowley, KSVIA SKYWARN.
23:49 UTCHAIL 26 N Arkansas CityCowley, KSMPING.
23:50 UTCTSTM WND DMG2 N Arkansas CityCowley, KSPOWER POLES DOWNED ON 41ST ROAD.
23:52 UTCHAIL 2.53 N Arkansas CityCowley, KS
00:28 UTCHAIL 2.57 Ene Arkansas CityCowley, KSMPING
00:32 UTCHAIL 1.2510 E Arkansas CityCowley, KS
00:33 UTCHAIL 0.752 S RockCowley, KS
00:40 UTCHAIL 1.25RockCowley, KS
00:42 UTCHAIL 1.757 Ese Arkansas CityCowley, KS
00:42 UTCHAIL 210 Sw DexterCowley, KSMPING
00:44 UTCHAIL 14 Ssw UdallCowley, KS
00:45 UTCHAIL 1.752 W Maple CityCowley, KS
02:45 UTCTSTM WND GST 602 N Arkansas CityCowley, KS
02:51 UTCTORNADO3 Ene Maple CityCowley, KS
03:20 UTCTORNADO1 W Cedar ValeChautauqua, KSDELAYED REPORT PER CHAUTAUQUA COUNTY LAW ENFORCEMENT. TIME ESTIMATED FROM RADAR.
03:25 UTCTSTM WND DMGCedar ValeChautauqua, KSTREE DAMAGE IN TOWN ALONG WITH AWNING FROM CITY POOL BLOWN OFF.

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 KansasEvery tornado in Kansas since 1950Warnings in force in Kansas nowThe forecast where you are

The other tornadoes of May 14, 2018

11 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 145:34 AM EDTEF0Palm Beach, FL1.550
May 1410:35 AM EDTEF0Brevard, FL0.150$500
May 1412:25 PM EDTEF0Martin, FL0.150$8,000
May 146:35 PM CDTEF0Cowley, KS0.350
May 146:40 PM CDTEF0Cowley, KS0.150
May 149:45 PM CDTEF2Cowley, KS0.875
May 149:48 PM CDTEF1Cowley, KS4.275
May 149:53 PM CDTEF0Cowley, KS0.350
May 149:56 PM CDTEF1Cowley, KS2.350
May 1410:06 PM CDTEF0Cowley, KS1.650
May 1410:22 PM CDTEF0Chautauqua, KS0.550

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.