Tornadoes · United States · Nebraska · 2021
Unrated tornado, Agate, Nebraska, May 26, 2021
This Unrated tornado ran 0.4 miles across Sioux County on May 26, 2021, touching down at 4:43 PM MDT and reaching 20 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.
EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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
- 4:43 PM MDT (22:43 UTC)
- Lifted
- 4:52 PM MDT (22:52 UTC)
- On the ground
- 9 minutes
- Path length
- 0.4 miles (0.6 km)
- Path width
- 20 yards (18 m)
- Deaths
- 0
- Injuries
- 0
- County
- Sioux County
- Touchdown point
- 42.410, -103.760
- Lift-off point
- 42.413, -103.754
- Record number
- 2105261643-01
What the Weather Service recorded
Several strong to severe thunderstorms moved across the Nebraska Panhandle producing large hail, damaging winds and a noted tornado near Agate Fossil Bed National Monument. Multiple photos and video confirmed evidence of tornado near the Agate Fossil Bed National Monument. Tornado remained over rural areas producing no discernable damage to rate other than unknown. Given sparse information and lack of damage, tornado path and width are estimates. In addition hail up to the size of baseballs were reported in the strongest storms on the 26th.
Multiple photos and video confirmed evidence of landspout tornado near the Agate Fossil Bed National Monument. Landspout remained over rural areas producing no discernable damage to rate other than unknown. Given sparse information and lack of damage, path and width are estimates.
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 19:27 UTC and running to 01:27 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 19:27 UTC | 01:27 UTC | Severe Thunderstorm Watch | CYS |
| 21:08 UTC | 21:45 UTC | Severe Thunderstorm Warning | CYS |
| 22:47 UTC | 23:15 UTC | Tornado Warning | CYS |
| 23:41 UTC | 00:15 UTC | Severe Thunderstorm Warning | CYS |
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 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.
Rapid City, SD (KUNR), 12:00Z
10.7 hours before the tornado, 198 km from the path. May 26, 2021.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -106439 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 797 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km bulk shear
- 10 kt
- 0-1 km storm-relative helicity
- 48 m²/s²
- 0-3 km storm-relative helicity
- 366 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 3.8 K/km
Rapid City, SD (KUNR), 00:00Z
1.3 hours after it, 198 km from the path. May 27, 2021.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -106630 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 570 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 370 m²/s²
- 0-3 km storm-relative helicity
- 626 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 4.3 K/km
The radar
The Cheyenne radar (KCYS), 165 km away, was scanning. The volume nearest the touchdown began at 22:44 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) | Report | Where | County | Remark |
|---|---|---|---|---|
| 20:51 UTC | HAIL 0.75 | 1 Nnw Agate | Sioux, NE | HAIL FELL FROM 251 TO 255. |
| 21:16 UTC | HAIL 1.25 | 7 Ene Agate | Sioux, NE | |
| 21:48 UTC | TSTM WND DMG | Fort Robinson | Sioux, NE | POWER OUTAGES AT RED CLOUD CAMPGROUND AND TREE LIMB BROKEN. |
| 22:43 UTC | TORNADO | 1 E Agate | Sioux, NE | UPDATED INFORMATION OF STARTING AT 443 AND LASTING FOR CLOSE TO TEN MINUTES. MULTIPLE TRAINED SPOTTER REPORTS, VIDEO, AND PICTURES CONFIRM A SHORT TORNADO TOUCH DOWN SOUTH OF THE AGATE FOSSIL BED MONUMENT. NO DAMAGE REPO |
| 22:43 UTC | TORNADO | 1 Ese Agate | Sioux, NE | CORRECTS PREVIOUS TORNADO REPORT FROM 1 ESE AGATE. MULTIPLE TRAINED SPOTTER REPORTS, VIDEO, AND PICTURES CONFIRM A SHORT TORNADO TOUCH DOWN SOUTH OF THE AGATE FOSSIL BED MONUMENT. NO DAMAGE REPORTED AS IT STAYED IN RURAL |
| 23:02 UTC | HAIL 1 | 1 Nnw Agate | Sioux, NE | HAIL REPORTED FALLING FROM 502 TO 506 PM. |
| 23:28 UTC | HAIL 2 | 10 West Hemingford | Box Butte, NE | PHOTO ON SOCIAL MEDIA READING 2.14 INCHES FOR DIAMETER. |
| 01:03 UTC | TORNADO | 1 Ese Agate | Sioux, NE | MULTIPLE TRAINED SPOTTER REPORTS, VIDEO, AND PICTURES CONFIRM A SHORT TORNADO TOUCH DOWN SOUTH OF THE AGATE FOSSIL BED MONUMENT. NO DAMAGE REPORTED AS IT STAYED IN RURAL AREAS. |
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.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| May 26 | 2:57 PM CDT | Unrated | Ellis, KS | 2.5 | 200 | |||
| May 26 | 3:22 PM CDT | EF0 | Ellis, KS | 0.5 | 100 | |||
| May 26 | 3:20 PM MDT | Unrated | Dundy, NE | 1.6 | 50 | |||
| May 26 | 3:25 PM MDT | EF0 | Dundy, NE | 1.9 | 350 | |||
| May 26 | 3:39 PM MDT | EF2 | Dundy, NE | 8.3 | 575 | |||
| May 26 | 3:49 PM MDT | Unrated | Dundy, NE | 0.1 | 50 | |||
| May 26 | 4:54 PM CDT | Unrated | Barton, KS | 0.3 | 50 | |||
| May 26 | 4:01 PM MDT | Unrated | Dundy, NE | 4.4 | 300 | |||
| May 26 | 5:10 PM CDT | Unrated | Barton, KS | 0.2 | 50 | |||
| May 26 | 5:19 PM CDT | Unrated | Rawlins, KS | 1.9 | 200 | |||
| May 26 | 5:23 PM CDT | Unrated | Hitchcock, NE | 1.8 | 100 | |||
| May 26 | 5:29 PM CDT | EF1 | Rawlins, KS | 3.5 | 450 | |||
| May 26 | 5:45 PM CDT | Unrated | Rawlins, KS | 2.4 | 100 | |||
| May 26 | 5:56 PM CDT | Unrated | Hansford, TX | 1.9 | 20 | |||
| May 26 | 6:14 PM CDT | Unrated | Hansford, TX | 0.8 | 20 | |||
| May 26 | 6:41 PM CDT | Unrated | Decatur, KS | 1.5 | 50 | |||
| May 26 | 6:49 PM CDT | EF0 | Rice, KS | 0.3 | 70 | $25,000 | ||
| May 26 | 7:34 PM CDT | Unrated | Ochiltree, TX | 1.3 | 20 | |||
| May 26 | 8:14 PM CDT | EF0 | Ochiltree, TX | 0.9 | 20 | |||
| May 26 | 9:32 PM CDT | Unrated | Hale, TX | 1.0 | 30 |
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.