Tornadoes · United States · Nebraska · 2003

F0 tornado, Lake Mc Conaghy, Nebraska, July 21, 2003

This F0 tornado ran 0.1 miles across Keith County on July 21, 2003, touching down at 6:53 PM MDT and reaching 10 yards wide. It killed nobody.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. F040 to 72 mphthis tornado

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F173 to 112 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 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. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 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
F0
Date
July 21, 2003
Touchdown
6:53 PM MDT (00:53 UTC)
Path length
0.1 miles (0.2 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
County
Keith County
Touchdown point
41.250, -101.700
Lift-off point
41.250, -101.700
Record number
512

What the Weather Service recorded

A weak tornado touched down briefly in an open pasture.

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

The warnings

12 minutes of warning. NWS LBF issued a tornado warning for this county at 00:41 UTC, 12 minutes before the tornado touched down, in force until 01:30 UTC.

Issued (UTC)ExpiredProductOffice
22:16 UTC23:00 UTCSevere Thunderstorm WarningLBF
22:47 UTC23:30 UTCTornado WarningLBF
23:27 UTC00:30 UTCTornado WarningLBF
00:41 UTC01:30 UTCTornado WarningLBF
01:36 UTC02:00 UTCTornado WarningLBF

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 19:22 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 surface observations

Ogallala (OGA), 16 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
23:29 UTC73.469.850° 22 kt421016.3+TSRA
23:40 UTC73.469.850° 22 kt421016.3
23:49 UTC73.469.8120° 15 kt1014.2-TSRA
23:50 UTC73.468120° 14 kt1014.2-TSRA
00:10 UTC7769.840° 9 kt141015.2-VCTSDZ
00:20 UTC7769.840° 9 kt141015.2
00:30 UTC78.869.890° 11 kt151014.6
00:40 UTC78.869.890° 11 kt151014.6
00:50 UTC776890° 12 kt161014.9
01:10 UTC7766.2100° 13 kt171015.2
01:20 UTC7766.2100° 13 kt171015.2
01:30 UTC7764.4100° 18 kt231015.6
01:40 UTC7764.4100° 18 kt231015.6
01:50 UTC7764.4110° 15 kt201015.9
02:10 UTC73.462.680° 15 kt201016.6RA
02:20 UTC73.462.680° 15 kt201016.6
02:30 UTC71.662.690° 6 kt1017.6-RA
02:40 UTC71.662.690° 6 kt1017.6
02:50 UTC69.862.6110° 7 kt1017.6

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

The radar

The North Platte radar (KLNX), 122 km away, was scanning. The volume nearest the touchdown began at 00:53 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.

This ground now

The live radar over the trackEvery 2003 tornado in NebraskaEvery tornado in Nebraska since 1950Warnings in force in Nebraska nowThe forecast where you are

The other tornadoes of July 21, 2003

25 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 213:15 AM ESTF0Cass, IN2.0100
July 214:00 AM ESTF0Tippecanoe, IN0.550
July 215:00 AM ESTF0Boone, IN2.550$10,000
July 211:45 PM EDTF1Mahoning, OH8.075$1.0 million
July 212:25 PM EDTF0Mercer, PA3.080$10,000
July 213:15 PM EDTF1McKean, PA5.5600$46 million
July 214:00 PM EDTF3Potter, PA2.5200$200,000
July 215:00 PM EDTF1Juniata, PA3.0200$20,000
July 215:30 PM EDTF1Lycoming, PA5.0900$10,000
July 215:38 PM ESTF0Daviess, IN0.550$10,000
July 217:20 PM EDTF1Sullivan, NY3.0200$100,000
July 218:14 PM EDTF1Greene, NY0.550$30,000
July 218:23 PM EDTF2Greene, NY1.51507$1.0 million
July 218:24 PM EDTF1Greene, NY0.550$10,000
July 218:30 PM EDTF1Greene, NY0.5150$100,000
July 218:32 PM EDTF1Columbia, NY1.890$150,000
July 218:35 PM EDTF0Columbia, NY0.4125$10,000
July 218:38 PM EDTF0Columbia, NY0.560$10,000
July 218:40 PM EDTF0Columbia, NY0.560$10,000
July 218:40 PM EDTF0Columbia, NY4.050$20,000
July 218:43 PM EDTF2Columbia, NY1.3501$200,000
July 218:45 PM EDTF1Rensselaer, NY4.890$50,000
July 219:20 PM EDTF1Bennington, VT25.0150$150,000
July 218:30 PM CDTF0Cheyenne, KS0.225
July 219:56 PM EDTF1Windham, VT2.0100$10,000

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.