Tornadoes · United States · Oklahoma · 2020

EF1 tornado, Row to Grove Arpt, Oklahoma, May 25, 2020

From Row to Grove Arpt, this EF1 tornado ran 0.3 miles across Delaware County on May 25, 2020, touching down at 7:45 PM CDT and reaching 75 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 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
May 25, 2020
Touchdown
7:45 PM CDT (00:45 UTC)
Lifted
7:46 PM CDT (00:46 UTC)
On the ground
1 minutes
Path length
0.3 miles (0.5 km)
Path width
75 yards (69 m)
Deaths
0
Injuries
0
County
Delaware County
Touchdown point
36.338, -94.632
Lift-off point
36.342, -94.634
Record number
2005251845-01

The damage survey

10 damage points were recorded along this path by NWS TSA, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 90 mph.

  • Damage seems to coincide with brief tornado photographed by KOTV chaser.
  • about 8 trees uprooted in this area

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

Thunderstorms developed during the afternoon of the 25th across southeastern Oklahoma, to the north of an upper level disturbance approaching the area from eastern Texas. The atmosphere had become moderately unstable ahead of the thunderstorms, and the low level wind shear had become strong. The combination of instability and wind shear promoted the development of supercell thunderstorms, which formed ahead of a squall line. The supercells produced multiple tornadoes, along with damaging wind.||These thunderstorms also produced widespread two to four inches of rain across much of eastern Oklahoma. This rainfall occurred following several days of rain, which resulted in five-day totals of four to eight inches across portions of eastern Oklahoma. Moderate flooding of the Neosho River near Commerce, and the Poteau River near Panama, resulted from this widespread heavy rain.

This tornado snapped large tree limbs, and was observed by storm chasers. Based on this damage, maximum estimated wind in the tornado was 70 to 80 mph.

This tornado uprooted trees. It likely had a longer path length, but occurred in a heavily-wooded area that was mostly inaccessible by road. Based on this damage, maximum estimated wind in the tornado was 85 to 95 mph.

This tornado snapped large tree limbs as it crossed several county roads. Based on this damage, maximum estimated wind in the tornado was 70 to 80 mph.

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

The warnings

45 minutes of warning. NWS TSA issued a tornado warning for this county at 00:00 UTC, 45 minutes before the tornado touched down, in force until 00:45 UTC.

The county was under a tornado watch, issued at 23:15 UTC and running to 02:51 UTC.

Issued (UTC)ExpiredProductOffice
18:00 UTC08:52 UTCFlash Flood WatchTSA
23:15 UTC02:51 UTCTornado WatchTSA
00:00 UTC00:45 UTCTornado WarningTSA
00:10 UTC00:45 UTCSevere Thunderstorm WarningTSA
00:40 UTC01:30 UTCTornado WarningTSA
00:45 UTC01:45 UTCSevere Thunderstorm WarningTSA
01:11 UTC02:00 UTCTornado WarningTSA
01:13 UTC04:15 UTCFlood AdvisoryTSA
01:38 UTC02:12 UTCSevere Thunderstorm WarningTSA
03:03 UTC09:00 UTCFlood WarningTSA
07:49 UTC19:17 UTCFlood AdvisoryTSA
07:49 UTC14:16 UTCFlood AdvisoryTSA
09:13 UTC15:15 UTCFlood 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 Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:53 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

0.8 hours before the tornado, 97 km from the path. May 26, 2020.

Skew-T log-pSkew-T log-p diagram, Springfield, MO at 00:00Z on 2020-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 211 joules per kilogram, CIN -63, lifted condensation level 1234 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, Springfield, MO at 00:00Z on 2020-05-26The 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 80 square meters per square second, 0 to 6 km bulk shear 34 knots.193958Sfc1 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
211 J/kg
Mixed-layer CIN
-63 J/kg
Surface CAPE
642 J/kg
Mixed-layer LCL
1234 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
24 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
86 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
6.4 K/km

Open this sounding in Storm Lab

Springfield, MO (KSGF), 12:00Z

11.2 hours after it, 97 km from the path. May 26, 2020.

Skew-T log-pSkew-T log-p diagram, Springfield, MO at 12:00Z on 2020-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 12 joules per kilogram, CIN -60, lifted condensation level 551 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, Springfield, MO at 12:00Z on 2020-05-26The 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 240 square meters per square second, 0 to 6 km bulk shear 34 knots.193958Sfc1 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
12 J/kg
Mixed-layer CIN
-60 J/kg
Surface CAPE
58 J/kg
Mixed-layer LCL
551 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
37 kt
0-1 km storm-relative helicity
240 m²/s²
0-3 km storm-relative helicity
194 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.4 K/km

Open this sounding in Storm Lab

The surface observations

Siloam Spring(Awos) (SLG), 21 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
22:15 UTC340° 5 kt1009.8
22:20 UTC340° 4 kt1009.8
22:25 UTC330° 5 kt1010.2
22:30 UTC340° 5 kt1010.2
22:35 UTC330° 7 kt1009.8
22:40 UTC 1009.8
22:45 UTC330° 8 kt1009.8
22:50 UTC330° 5 kt1009.8
22:55 UTC330° 5 kt1010.2
22:56 UTC7468330° 6 kt1010.2
23:00 UTC320° 8 kt1009.8
23:05 UTC330° 8 kt1009.8
23:10 UTC340° 8 kt1009.5
23:15 UTC350° 8 kt1009.5
23:20 UTC340° 7 kt1009.5
23:25 UTC360° 10 kt1009.1
23:30 UTC350° 7 kt1009.5
23:35 UTC350° 8 kt1009.5
23:40 UTC10° 9 kt1009.5-RA
23:45 UTC360° 5 kt1009.1RA
23:50 UTC360° 5 kt1009.1-RA
23:55 UTC20° 8 kt1009.1-RA
23:56 UTC716720° 8 kt1008.8-RA
00:00 UTC10° 8 kt1008.8-RA
00:05 UTC20° 8 kt1008.8-RA
00:10 UTC20° 9 kt1008.8-RA
00:15 UTC30° 8 kt1008.8
00:20 UTC50° 5 kt1009.1
00:25 UTC50° 2 kt1009.1
00:30 UTC30° 4 kt1009.1
00:35 UTC30° 5 kt1009.1
00:40 UTC30° 5 kt1009.1
00:45 UTC30° 5 kt1008.8
00:50 UTC30° 5 kt1008.8
00:55 UTC0° 0 kt1009.1
00:56 UTC71670° 0 kt
01:00 UTC200° 351010.8BR
01:03 UTC6864.4210° 24 kt351010.8+RA BR
01:05 UTC190° 28+RA BR
01:07 UTC64.462.6200° 16 kt351011.2+RA BR
01:10 UTC190° 5 kt1010.8+RA BR
01:11 UTC64.462.6190° 5 kt281010.5+RA BR
01:15 UTC210° 4 kt1010.5RA BR
01:16 UTC64.462.6220° 3 kt1010.5RA BR
01:20 UTC180° 4 kt1010.5-RA
01:25 UTC180° 5 kt1010.5-RA
01:30 UTC200° 7 kt1010.5-RA
01:35 UTC190° 7 kt1010.5RA
01:40 UTC210° 5 kt1010.5RA
01:45 UTC190° 5 kt1010.5-RA
01:50 UTC0° 0 kt1010.5RA
01:55 UTC0° 0 kt1010.5RA BR
01:56 UTC64630° 0 kt1010.5RA BR
02:00 UTC0° 0 kt1010.5RA BR
02:05 UTC0° 0 kt1010.5-RA
02:10 UTC0° 0 kt1010.5RA

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

The radar

The Tulsa radar (KINX), 85 km away, was scanning. The volume nearest the touchdown began at 00:42 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
00:07 UTCTORNADOWest Siloam SpringsDelaware, OKA TORNADO WAS VERIFIED THROUGH BROADCAST MEDIA VIDEO NEAR WEST SILOAM SPRINGS. TIME AND LOCATION IS ESTIMATED FROM RADAR.
00:34 UTCTORNADO5 Ene ColcordDelaware, OKA TORNADO SNAPPED LARGE TREE LIMBS.
00:37 UTCTSTM WND GST 70ColcordDelaware, OKHAM RADIO OPERATOR REPORTS AN ESTIMATED WIND GUST OF 70 MILES PER HOUR.
00:45 UTCTORNADO5 Ssw MaysvilleDelaware, OKA TORNADO UPROOTED TREES
01:16 UTCTORNADO11 Ne JayDelaware, OKA TORNADO SNAPPED LARGE TREE LIMBS ALONG A NARROW PATH FOR MORE THAN 2 MILES

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 May 25, 2020

10 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 252:30 PM CDTEF0Buchanan, MO0.020
May 255:05 PM CDTEF1Titus, TX0.5100$60,000
May 255:37 PM CDTEF0Sequoyah, OK0.5100$100,000
May 255:38 PM CDTEF1Lafayette, AR0.340$200,000
May 255:58 PM CDTUnratedSebastian, AR1.375
May 256:12 PM CDTUnratedSabine Parish, LA2.340
May 256:26 PM CDTEF1Polk, IA1.650
May 257:11 PM CDTEF1Adair, OK0.6120
May 257:34 PM CDTEF0Delaware, OK0.150
May 258:13 PM CDTEF0Delaware, OK2.2300

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.