Tornadoes · United States · Nebraska · 2021

Unrated tornado, Benkelman to Max, Nebraska, May 26, 2021

From Benkelman to Max, this Unrated tornado ran 1.6 miles across Dundy County on May 26, 2021, touching down at 3:20 PM MDT 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 26, 2021
Touchdown
3:20 PM MDT (21:20 UTC)
Lifted
3:22 PM MDT (21:22 UTC)
On the ground
2 minutes
Path length
1.6 miles (2.5 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Dundy County
Touchdown point
40.109, -101.539
Lift-off point
40.124, -101.561
Record number
2105261520-01

The damage survey

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

  • Shed was thrown 200 yards damaged fence and hydrant as it was thrown
  • Noticed grass debris laying sse, marking potential highway crossing
  • 3 new poles broken at base
  • Damage was a bit more sporadic here

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 semi stationary warm front across part of far Southwest Nebraska into Northwest Kansas served as the trigger for thunderstorm development during the afternoon and evening hours. Storms developed and moved north of the front producing tornadoes, hail up to tennis ball size, and a report of thunderstorm wind damage in McCook. The largest hail reported was north of Max. Two tornadoes formed north of the Benkelman and Max area, one causing damage. The report of thunderstorm wind damage was one inch diameter tree limbs and some shingles being blown down near McCook.

Trusted newspaper writer and trained spotter reported brief tornado touchdown north of Benkelman. Locations confirmed by radar imagery. No damage reported and tornado did not last long before the EF-0 began 3 minutes later. There was a distinct break in the track between this one and the following EF-0.

A brief tornado occurred 5 miles north of Benkelman. Damage consisted of some metal roofing panels, a shed was thrown 200 yards, and fencing was damaged. The tornado crossed Highway 61 and ended on the west side of the highway. There was a distinct break in the tracks between this tornado and the EF-2 that began a few minutes later.

An EF-2 tornado occurred shortly after the brief EF-0 north of Benkelman. Damage consisted of many broken power poles, a large grove of Elm Trees that were demolished, additional trees that were snapped or uprooted, damage to a residence including loss of shingles, loss of metal roofing panels to a farm outbuilding, a tractor was moved 100 yards, and damage to antique vehicles due to falling tree debris. The tornado moved along Highway 61 for most of its life, snapping more power poles and twisting signs. The tornado seemed to stray slightly west of the highway and continued according to spotter and chaser reports. The tornado eventually ended over open fields.

Brief tornado reported by off-duty NWS employees. Occurred around the same time as the Dundy County EF-2 tornado.

Law enforcement and off-duty NWS employees reported another new, large tornado formed in extreme eastern Dundy County. This tornado continued for around 20 minutes until it roped out in the far northeastern part of the county.

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.

Issued (UTC)ExpiredProductOffice
16:14 UTC16:54 UTCSevere Thunderstorm WarningGLD
21:05 UTC22:00 UTCSevere Thunderstorm WarningGLD
21:18 UTC22:15 UTCSevere Thunderstorm WarningGLD
21:23 UTC22:15 UTCTornado WarningGLD
21:42 UTC04:17 UTCTornado WatchGLD
21:46 UTC22:15 UTCTornado WarningGLD
22:03 UTC22:45 UTCTornado WarningGLD
22:31 UTC22:44 UTCTornado WarningGLD

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 Moderate 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 19:57 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.

N. Platte/Lee Bi, NE (KLBF), 12:00Z

9.3 hours before the tornado, 138 km from the path. May 26, 2021.

Skew-T log-pSkew-T log-p diagram, N. Platte/Lee Bi, NE at 12:00Z on 2021-05-26Temperature 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 -86701, lifted condensation level 2021 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, N. Platte/Lee Bi, NE at 12:00Z on 2021-05-26The 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 141 square meters per square second, 0 to 6 km bulk shear 39 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
-86701 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
2021 m above ground
0-6 km bulk shear
39 kt
0-1 km bulk shear
10 kt
0-1 km storm-relative helicity
141 m²/s²
0-3 km storm-relative helicity
171 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.6 K/km

Open this sounding in Storm Lab

N. Platte/Lee Bi, NE (KLBF), 00:00Z

2.7 hours after it, 138 km from the path. May 27, 2021.

Skew-T log-pSkew-T log-p diagram, N. Platte/Lee Bi, NE at 00:00Z on 2021-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 124 joules per kilogram, CIN -115, lifted condensation level 1622 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, N. Platte/Lee Bi, NE at 00:00Z on 2021-05-27The 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 149 square meters per square second, 0 to 6 km bulk shear 52 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
124 J/kg
Mixed-layer CIN
-115 J/kg
Surface CAPE
324 J/kg
Mixed-layer LCL
1622 m above ground
0-6 km bulk shear
52 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
149 m²/s²
0-3 km storm-relative helicity
363 m²/s²
Significant tornado parameter
0.1
Supercell composite
9.7
0-3 km lapse rate
7.3 K/km

Open this sounding in Storm Lab

The radar

The Goodland radar (KGLD), 84 km away, was scanning. The volume nearest the touchdown began at 21:18 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
21:25 UTCTORNADO5 N BenkelmanDundy, NEA BRIEF TORNADO OCCURRED 5 MILES NORTH OF BENKELMAN. DAMAGE CONSISTED OF SOME METAL ROOFING PANELS, A SHED WAS THROWN 200 YARDS, AND FENCING WAS DAMAGED. THE TORNADO CROSS HIGHWAY 61 AND ENDED ON THE WEST SIDE OF THE HIG
21:26 UTCTORNADO6 N BenkelmanDundy, NE
21:39 UTCTORNADO4 N BenkelmanDundy, NECORRECTS PREVIOUS TORNADO REPORT FROM 4 N BENKELMAN. REPORT OF STOVEPIPE TORNADO ON THE GROUND ON HWY 61... TELEPHONE POLES AND TREES DOWN REMAINING OVER OPEN COUNTRY.
21:39 UTCTORNADO4 N BenkelmanDundy, NEREPORT OF STOVEPIPE TORNADO ON THE GROUND ON HWY 61.
21:39 UTCTORNADO7 N BenkelmanDundy, NEAN EF-2 TORNADO OCCURRED SHORTLY AFTER THE BRIEF EF-0 NORTH OF BENKELMAN. DAMAGE CONSISTED OF MANY BROKEN POWER POLES, A LARGE GROVE OF ELM TREES THAT WERE DEMOLISHED, ADDITIONAL TREES THAT WERE SNAPPED OR UPROOTED, DAMA
21:46 UTCHAIL 1.255 N BenkelmanDundy, NEDELAYED REPORT BY TRAINED SPOTTER.
21:51 UTCTORNADO12 Nw MaxDundy, NETRAINED SPOTTER LOCATED TO THE EAST OF THE STORM IN NORTHWEST HITCHCOCK COUNTY REPORTED THEY CAN SEE THE TORNADO IN DUNDY COUNTY. IT WAS REPORTED AS A STOVE PIPE TORNADO.
21:55 UTCTORNADO12 Nw MaxDundy, NETORNADO STILL ON THE GROUND, STARTING TO ROPE OUT. GOLF BALL SIZE HAIL REPORTED AS WELL.
22:03 UTCTORNADO8 N MaxDundy, NENEW TORNADO ON GROUND WITH EAST CIRCULATION AT MM16 ON HWY 61.
22:11 UTCTORNADO4 Nne MaxDundy, NEPUBLIC REPORTED TORNADO.
22:19 UTCHAIL 1.7513 Nw StrattonDundy, NE
22:23 UTCTORNADO11 Wsw PalisadeHitchcock, NESPOTTER WAS LOCATED IN EXTREME SOUTHERN CHASE COUNTY LOOKING SOUTH.
22:25 UTCHAIL 2.512 N MaxDundy, NE
22:58 UTCHAIL 2.75Se HamletHayes, NEREPORT VIA SPOTTER NETWORK

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

This ground now

The live radar over the trackEvery 2021 tornado in NebraskaEvery tornado in Nebraska since 1950Warnings in force in Nebraska nowThe forecast where you are

The other tornadoes of May 26, 2021

20 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 262:57 PM CDTUnratedEllis, KS2.5200
May 263:22 PM CDTEF0Ellis, KS0.5100
May 263:25 PM MDTEF0Dundy, NE1.9350
May 263:39 PM MDTEF2Dundy, NE8.3575
May 263:49 PM MDTUnratedDundy, NE0.150
May 264:54 PM CDTUnratedBarton, KS0.350
May 264:01 PM MDTUnratedDundy, NE4.4300
May 265:10 PM CDTUnratedBarton, KS0.250
May 265:19 PM CDTUnratedRawlins, KS1.9200
May 265:23 PM CDTUnratedHitchcock, NE1.8100
May 265:29 PM CDTEF1Rawlins, KS3.5450
May 264:43 PM MDTUnratedSioux, NE0.420
May 265:45 PM CDTUnratedRawlins, KS2.4100
May 265:56 PM CDTUnratedHansford, TX1.920
May 266:14 PM CDTUnratedHansford, TX0.820
May 266:41 PM CDTUnratedDecatur, KS1.550
May 266:49 PM CDTEF0Rice, KS0.370$25,000
May 267:34 PM CDTUnratedOchiltree, TX1.320
May 268:14 PM CDTEF0Ochiltree, TX0.920
May 269:32 PM CDTUnratedHale, TX1.030

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.