Tornadoes · United States · Nebraska · 2021

EF0 tornado, Hartington, Nebraska, May 5, 2021

This EF0 tornado ran 0.9 miles across Cedar County on May 5, 2021, touching down at 4:42 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 mphthis tornado

    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. 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
EF0
Date
May 5, 2021
Touchdown
4:42 PM CDT (21:42 UTC)
Path length
0.9 miles (1.5 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Cedar County
Touchdown point
42.630, -97.280
Lift-off point
42.630, -97.280
Record number
2105051542-01

The damage survey

3 damage points were recorded along this path by NWS OAX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 79 mph.

  • Tornado started west of the Hartington Golf Course in a field with lots of corn stubble.
  • Two large oak branches down from trees
  • Shingles off several homes

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 along a cold front producing two tornadoes and hail and wind reports.

Emergency manager reported a tornado. The tornado started in a field northwest of the Hartington Golf Course and moved southeast. The tornado crossed Nebraska Highway 57 and ended in a residential section of town. A couple large tree limbs were ripped off oak trees in the golf course. Some roofs of homes sustained loss of shingles. Corn stubble from the corn field northwest of the golf course was deposited across parts of Hartington.

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
20:47 UTC21:30 UTCSevere Thunderstorm WarningOAX
21:45 UTC22:15 UTCTornado WarningOAX

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 General Thunderstorms Risk. The outlook in force was issued at 21:07 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.

Omaha, NE (KOAX), 12:00Z

9.7 hours before the tornado, 164 km from the path. May 5, 2021.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 12:00Z on 2021-05-05Temperature 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 -94689, lifted condensation level 2603 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, Omaha, NE at 12:00Z on 2021-05-05The 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 47 square meters per square second, 0 to 6 km bulk shear 28 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
0 J/kg
Mixed-layer CIN
-94689 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
2603 m above ground
0-6 km bulk shear
28 kt
0-1 km bulk shear
6 kt
0-1 km storm-relative helicity
47 m²/s²
0-3 km storm-relative helicity
75 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.8 K/km

Open this sounding in Storm Lab

Omaha, NE (KOAX), 00:00Z

2.3 hours after it, 164 km from the path. May 6, 2021.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 2021-05-06Temperature 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 -87817, lifted condensation level 1912 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, Omaha, NE at 00:00Z on 2021-05-06The 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 136 square meters per square second, 0 to 6 km bulk shear 45 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
-87817 J/kg
Surface CAPE
15 J/kg
Mixed-layer LCL
1912 m above ground
0-6 km bulk shear
45 kt
0-1 km bulk shear
12 kt
0-1 km storm-relative helicity
136 m²/s²
0-3 km storm-relative helicity
159 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
7.5 K/km

Open this sounding in Storm Lab

The surface observations

Yankton (YKN), 33 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:45 UTC150° 11 kt1016.9
19:50 UTC150° 10 kt1016.9
19:55 UTC140° 14 kt1016.6
19:56 UTC6246140° 13 kt1016.6
20:00 UTC140° 9 kt141016.6
20:05 UTC150° 13 kt1016.6
20:10 UTC130° 11 kt1016.6
20:15 UTC160° 14 kt1016.3
20:20 UTC140° 11 kt1016.3
20:25 UTC150° 10 kt1016.6
20:30 UTC120° 11 kt1016.6
20:32 UTC62.646.4110° 13 kt1016.3VCTS
20:35 UTC120° 14 kt1016.3
20:40 UTC110° 11 kt1016.3
20:45 UTC130° 11 kt1016.3
20:50 UTC130° 11 kt1016.3
20:52 UTC62.646.4130° 10 kt1016.3VCTS
20:55 UTC140° 10 kt1016.3
20:56 UTC6347140° 11 kt151016.3VCTS
21:00 UTC130° 8 kt1016.3
21:05 UTC110° 8 kt1015.9
21:10 UTC110° 5 kt1016.3
21:13 UTC62.648.2100° 8 kt1016.3
21:15 UTC130° 5 kt1016.3
21:20 UTC140° 9 kt141016.3
21:25 UTC150° 9 kt1016.3
21:30 UTC110° 7 kt1016.3
21:35 UTC90° 5 kt1016.3
21:40 UTC80° 5 kt1016.3
21:45 UTC120° 5 kt1016.3
21:50 UTC100° 5 kt1016.3
21:55 UTC80° 2 kt1016.6-RA
21:56 UTC61470° 0 kt1016.6-RA
22:00 UTC0° 0 kt1016.3RA
22:05 UTC0° 0 kt1016.6RA
22:10 UTC50° 2 kt1016.6-RA
22:15 UTC30° 5 kt1016.6-RA
22:20 UTC40° 5 kt1016.6-RA
22:25 UTC30° 2 kt1016.6-RA
22:30 UTC350° 4 kt1016.9
22:35 UTC10° 7 kt1016.9
22:40 UTC30° 16 kt1016.9
22:45 UTC40° 15 kt1016.9
22:50 UTC40° 15 kt1016.9
22:55 UTC40° 15 kt1017.3
22:56 UTC614840° 13 kt1017.3
23:00 UTC50° 18 kt1017.3
23:05 UTC40° 15 kt1017.3
23:10 UTC50° 16 kt1017.3
23:15 UTC40° 19 kt1017.6
23:20 UTC30° 18 kt221017.6
23:25 UTC30° 20 kt1017.9
23:30 UTC30° 20 kt1017.9
23:35 UTC30° 22 kt1017.9
23:40 UTC30° 18 kt1018.3

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

The radar

The Sioux Falls radar (KFSD), 116 km away, was scanning. The volume nearest the touchdown began at 21:40 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
21:16 UTCHAIL 15 Ene FordyceCedar, NEGROUND COVERED. HAIL SIZES RANGE FROM PEA UP TO QUARTER SIZE.
21:42 UTCTORNADO1 Nw HartingtonCedar, NEAN EF-0 TORNADO TRACK BEGAN NORTHWEST OF THE HARTINGTON GOLF COURSE, AND CONTINUED TO THE SOUTHEAST INTO HARTINGTON FOR APPROXIMATELY 4 MINUTES, ENDING AT APPROXIMATELY 446 PM. MINOR TREE AND ROOF DAMAGE OCCURRED WITH BR
21:43 UTCTORNADO7 E HartingtonCedar, NE

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 5, 2021

2 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 54:10 PM CDTUnratedMadison, NE0.125
May 54:30 PM CDTUnratedClay, NE0.040

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.