Tornadoes · United States · Oklahoma · 2020

EF1 tornado, Cobb to Caddo, Oklahoma, April 22, 2020

From Cobb to Caddo, this EF1 tornado ran 1.2 miles across Bryan County on April 22, 2020, touching down at 5:52 PM CDT and reaching 30 yards wide. It killed nobody, and did $20,000 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 mphthis tornado

    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
EF1
Date
April 22, 2020
Touchdown
5:52 PM CDT (22:52 UTC)
Lifted
5:53 PM CDT (22:53 UTC)
On the ground
1 minutes
Path length
1.2 miles (1.9 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
Property damage
$20,000
County
Bryan County
Touchdown point
34.068, -96.221
Lift-off point
34.068, -96.242
Record number
2004221652-01

The damage survey

21 damage points were recorded along this path by NWS OUN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 104 mph.

  • 5 poles down. Inaccessible
  • Large branches broken off on close-range storm chaser video.

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

A dryline and upper level wave combined with strong shear to produce multiple tornadic supercells across southern Oklahoma on the 22nd.

This tornado touched down about 3 miles west-northwest of Armstrong and moved generally east for 5 miles damaging a number of homes, barns and trees.

A tornado was observed at close range by a storm chaser. The tornado was observed to break branches off a number of trees, and damage a building as it crossed Robinson Road, then cross over a pond.

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

The warnings

37 minutes of warning. NWS OUN issued a tornado warning for this county at 22:15 UTC, 37 minutes before the tornado touched down, in force until 23:00 UTC.

The county was under a tornado watch, issued at 19:34 UTC and running to 00:26 UTC.

Issued (UTC)ExpiredProductOffice
06:48 UTC09:20 UTCSevere Thunderstorm WatchOUN
06:50 UTC08:00 UTCSevere Thunderstorm WarningOUN
07:24 UTC08:15 UTCSevere Thunderstorm WarningOUN
08:12 UTC08:41 UTCSevere Thunderstorm WarningOUN
13:53 UTC19:34 UTCSevere Thunderstorm WatchOUN
15:41 UTC16:11 UTCSevere Thunderstorm WarningOUN
19:34 UTC00:26 UTCTornado WatchOUN
21:58 UTC22:45 UTCTornado WarningOUN
22:05 UTC22:45 UTCSevere Thunderstorm WarningOUN
22:15 UTC23:00 UTCTornado WarningOUN
22:39 UTC23:19 UTCTornado WarningOUN
22:45 UTC23:30 UTCTornado 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 Enhanced Risk, with a 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 19:37 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

10.9 hours before the tornado, 167 km from the path. April 22, 2020.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z on 2020-04-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 20 joules per kilogram, CIN -449, lifted condensation level 1138 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 2020-04-22The 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 375 square meters per square second, 0 to 6 km bulk shear 65 knots.1939587897117Sfc1 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
20 J/kg
Mixed-layer CIN
-449 J/kg
Surface CAPE
99 J/kg
Mixed-layer LCL
1138 m above ground
0-6 km bulk shear
65 kt
0-1 km bulk shear
28 kt
0-1 km storm-relative helicity
375 m²/s²
0-3 km storm-relative helicity
455 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5
0-3 km lapse rate
4.1 K/km

Open this sounding in Storm Lab

Norman, OK (KOUN), 00:00Z

1.1 hours after it, 167 km from the path. April 23, 2020.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2020-04-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 18 joules per kilogram, CIN -176, lifted condensation level 1051 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 2020-04-23The 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 -148 square meters per square second, 0 to 6 km bulk shear 49 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
18 J/kg
Mixed-layer CIN
-176 J/kg
Surface CAPE
1076 J/kg
Mixed-layer LCL
1051 m above ground
0-6 km bulk shear
49 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
-148 m²/s²
0-3 km storm-relative helicity
-24 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.3
0-3 km lapse rate
6.1 K/km

Open this sounding in Storm Lab

The radar

The Norman radar (KTLX), 170 km away, was scanning. The volume nearest the touchdown began at 22:50 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
21:51 UTCTORNADO4 Sw MadillMarshall, OKA BRIEF TORNADO DEVELOPED ABOUT 4 MILES SOUTHWEST OF MADILL.
21:53 UTCTORNADOMadillMarshall, OK*** 1 FATAL *** A DAMAGING TORNADO MOVED THROUGH MADILL, DAMAGING NUMEROUS HOMES, BUSINESSES AND INDUSTRIAL BUILDINGS. THE TORNADO CONTINUED TO APPROXIMATELY 505 PM DISSIPATING EAST OF TOWN.
22:12 UTCTORNADOLittle CityMarshall, OKA TORNADO WAS REPORTED NEAR LITTLE CITY.
22:15 UTCHAIL 2.75NidaJohnston, OKBASEBALL SIZE HAIL IN NIDA, OK AT 77 AND 22.
22:26 UTCTORNADO1 S BromideJohnston, OKA TORNADO DEVELOPED SOUTH OF BROMIDE AND MOVED EAST PASSING NEAR OR NORTH OF WAPANUCKA.
22:32 UTCTORNADO4 Wnw ArmstrongBryan, OKA LARGE TORNADO DEVELOPED WEST-NORTHWEST OF ARMSTRONG AND MOVED EAST PASSING NORTH AND NORTHEAST OF ARMSTRONG TO AT LEAST 538 PM. HOMES WERE DAMAGED IN THE LAKE DURANT AREA AND NEAR ARMSTRONG.
22:32 UTCTORNADO7 Sw LehighAtoka, OKA TORNADO DEVELOPED NEAR THE ATOKA-COAL COUNTY LINE ABOUT 7 MILES SOUTHWEST OF LEHIGH AND MOVED EAST DISSIPATING APPROXIMATELY 559 PM SOUTH OR SOUTH-SOUTHWEST OF LEHIGH.
22:53 UTCTORNADO5 Se CaddoBryan, OKA DAMAGING TORNADO WAS REPORTED SOUTHEAST OF CADDO.

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

This ground now

The live radar over the trackEvery 2020 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

The other tornadoes of April 22, 2020

19 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 224:17 PM CDTEF1Garvin, OK2.2600$200,000
April 224:23 PM CDTEF0Carter, OK0.120$2,000
April 224:24 PM CDTEF2Murray, OK4.7600
April 224:45 PM CDTUnratedMarshall, OK0.250
April 224:53 PM CDTEF2Marshall, OK4.340021$500,000
April 225:10 PM CDTEF0Marshall, OK1.450$20,000
April 225:26 PM CDTEF1Johnston, OK5.0100$100,000
April 225:32 PM CDTEF1Bryan, OK5.2500$100,000
April 225:35 PM CDTEF3Onalaska tornado, TX28.51,100333$5.0 million
April 225:59 PM CDTEF0Coal, OK0.130
April 226:35 PM CDTEF1Lamar, TX4.5510$5,000
April 226:51 PM CDTEF2Lamar, TX10.4810$75,000
April 227:28 PM CDTEF2Newton, TX to LA36.4600$475,000
April 229:09 PM CDTEF2Rapides Parish, LA8.4500$150,000
April 229:26 PM CDTEF2Rapides Parish, LA9.05501$1.0 million
April 229:27 PM CDTEF1Rapides Parish, LA3.9500$100,000
April 229:42 PM CDTEF1Rapides Parish, LA5.4200$150,000
April 2210:06 PM CDTEF1Avoyelles Parish, LA7.61,200$82,000
April 2210:17 PM CDTEF1Concordia Parish, LA4.0880$33,000

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.