Tornadoes · United States · Oklahoma · 2019

Unrated tornado, Buffalo, Oklahoma, May 23, 2019

This Unrated tornado ran 0.5 miles across Harper County on May 23, 2019, touching down at 9:32 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 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 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. Unratedthis tornado

    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
Unrated
Date
May 23, 2019
Touchdown
9:32 PM CDT (02:32 UTC)
Lifted
9:33 PM CDT (02:33 UTC)
On the ground
1 minutes
Path length
0.5 miles (0.8 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Harper County
Touchdown point
36.830, -99.720
Lift-off point
36.830, -99.720
Record number
1905232032-01

The damage survey

1 damage points were recorded along this path by NWS OUN, in the Damage Assessment Toolkit the survey teams carry. The highest wind the damage implies is 74 mph.

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

Isolated supercells that developed in the Texas Panhandle and moved into far northwestern Oklahoma with tornadoes and wind reported on the 23rd.

An Oklahoma City television storm chaser observed a tornado estimated to be about 5 miles west of Buffalo. No damage was reported.

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

The warnings

28 minutes of warning. NWS OUN issued a tornado warning for this county at 02:04 UTC, 28 minutes before the tornado touched down, in force until 02:45 UTC.

The county was under a tornado watch, issued at 20:11 UTC and running to 02:54 UTC.

Issued (UTC)ExpiredProductOffice
20:11 UTC02:54 UTCTornado WatchOUN
01:15 UTC02:00 UTCSevere Thunderstorm WarningOUN
01:30 UTC02:15 UTCTornado WarningOUN
02:04 UTC02:45 UTCTornado WarningOUN
02:34 UTC03:15 UTCTornado WarningOUN
02:38 UTC03:30 UTCSevere Thunderstorm WarningOUN
02:43 UTC03:15 UTCTornado WarningOUN
02:54 UTC07:00 UTCTornado WatchOUN
03:11 UTC06:15 UTCFlood AdvisoryOUN
03:31 UTC04:15 UTCSevere Thunderstorm WarningOUN
03:42 UTC03:59 UTCTornado WarningOUN
04:45 UTC05:30 UTCSevere Thunderstorm WarningOUN
06:19 UTC07:00 UTCSevere Thunderstorm WarningOUN
07:16 UTC14:15 UTCFlood WarningOUN
18:32 UTC19:15 UTCSevere Thunderstorm WarningOUN
19:05 UTC19:28 UTCSevere Thunderstorm WarningOUN
19:19 UTC00:14 UTCTornado WatchOUN

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 01:04 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.

Dodge City, (KDDC), 12:00Z

9.5 hours after it, 106 km from the path. May 24, 2019.

Skew-T log-pSkew-T log-p diagram, Dodge City, at 12:00Z on 2019-05-24Temperature 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 -81763, lifted condensation level 2066 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Dodge City, at 12:00Z on 2019-05-24The 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 13 square meters per square second, 0 to 6 km bulk shear 76 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
0 J/kg
Mixed-layer CIN
-81763 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
2066 m above ground
0-6 km bulk shear
76 kt
0-1 km bulk shear
3 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
237 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
2.9 K/km

Open this sounding in Storm Lab

The surface observations

West Woodward (WWR), 47 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
00:35 UTC71.664.4140° 18 kt221011.9
00:55 UTC73.464.4140° 16 kt231011.9-RA
01:15 UTC71.664.4140° 15 kt211012.2
01:35 UTC71.664.4140° 13 kt201011.9
01:55 UTC71.664.4130° 15 kt241011.9VCTS
02:15 UTC71.664.4120° 12 kt1012.5TS
02:35 UTC71.664.4140° 11 kt141013.2
02:55 UTC71.664.4130° 14 kt1012.9
03:15 UTC71.662.6140° 16 kt221013.2
03:35 UTC71.662.6140° 18 kt241012.9
03:55 UTC71.662.6140° 18 kt251013.2
04:15 UTC71.662.6150° 17 kt201013.5

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

The radar

The Dodge City radar (KDDC), 106 km away, was scanning. The volume nearest the touchdown began at 02:33 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
01:51 UTCTORNADO6 E SlapoutBeaver, OK
01:52 UTCTORNADO7 Sw LaverneHarper, OK

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

This ground now

The live radar over the trackEvery 2019 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

The other tornadoes of May 23, 2019

18 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 231:10 AM CDTEF1Piatt, IL1.3200
May 231:49 AM CDTEF1Laclede, MO11.1440$155,000
May 232:06 AM CDTEF1Vermilion, IL1.6200
May 238:15 AM CDTEF0Clay, IL0.720
May 233:27 PM EDTEF1Howard, MD5.51501
May 235:15 PM EDTEF1Grant, IN0.150
May 235:01 PM CDTEF0Randall, TX0.650
May 235:13 PM CDTEF0Armstrong, TX0.750
May 235:15 PM CDTEF0Randall, TX0.350
May 235:28 PM CDTUnratedTerry, TX0.110
May 236:14 PM CDTEF1Roberts, TX9.150
May 236:59 PM CDTEF2Roberts, TX17.5900
May 237:07 PM CDTEF0Roberts, TX0.020
May 239:14 PM EDTEF0Cambria, PA1.6300$10,000
May 238:26 PM CDTEF3Lipscomb, TX to OK15.71,500$170,000
May 238:43 PM CDTEF0Lipscomb, TX4.575
May 239:43 PM CDTUnratedHarper, OK0.575
May 2310:42 PM CDTEF1Harper, OK2.0150$20,000

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.