Tornadoes · United States · North Dakota · 2001
F3 tornado, Pekin, North Dakota, July 18, 2001
This F3 tornado ran 5.0 miles across Nelson County on July 18, 2001, touching down at 6:05 PM CDT and reaching 150 yards wide. It killed nobody, and did $200,000 of property damage.
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.
F040 to 72 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
F173 to 112 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
F3158 to 206 mphthis tornado
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
F4207 to 260 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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
- F3
- Date
- July 18, 2001
- Touchdown
- 6:05 PM CDT (23:05 UTC)
- Path length
- 5.0 miles (8.0 km)
- Path width
- 150 yards (137 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $200,000
- County
- Nelson County
- Touchdown point
- 47.680, -98.450
- Lift-off point
- 47.720, -98.320
- Record number
- 1050
What the Weather Service recorded
A tornado hit the home of the Nelson county sheriff, who was out of town at the time. The tornado tore the roof off the house and destroyed the barn. A piece of farm machinery was thrown through the bedroom wall and a tractor was hurled 75 yards. The sheriff's squad car was crushed.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
5 minutes of warning. NWS FGF issued a tornado warning for this county at 23:00 UTC, 5 minutes before the tornado touched down, in force until 23:30 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 22:43 UTC | 23:30 UTC | Severe Thunderstorm Warning | FGF |
| 23:00 UTC | 23:30 UTC | Tornado Warning | FGF |
| 23:26 UTC | 00:15 UTC | Tornado Warning | FGF |
| 00:09 UTC | 01:00 UTC | Tornado Warning | FGF |
| 00:17 UTC | 03:15 UTC | Flash Flood Warning | FGF |
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. The outlook in force was issued at 19:46 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.
Bismarck Municip, ND (KBIS), 12:00Z
11.1 hours before the tornado, 203 km from the path. July 18, 2001.
- Mixed-layer CAPE
- 1501 J/kg
- Mixed-layer CIN
- -233 J/kg
- Surface CAPE
- 951 J/kg
- Mixed-layer LCL
- 728 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- 19 m²/s²
- 0-3 km storm-relative helicity
- 57 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 3.6 K/km
Bismarck Municip, ND (KBIS), 00:00Z
0.9 hours after it, 203 km from the path. July 19, 2001.
- Mixed-layer CAPE
- 2623 J/kg
- Mixed-layer CIN
- -63 J/kg
- Surface CAPE
- 4942 J/kg
- Mixed-layer LCL
- 1396 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km bulk shear
- 4 kt
- 0-1 km storm-relative helicity
- 15 m²/s²
- 0-3 km storm-relative helicity
- 182 m²/s²
- Significant tornado parameter
- 0.3
- Supercell composite
- 4.4
- 0-3 km lapse rate
- 7.4 K/km
The surface observations
Devils_lake (DVL), 60 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 21:15 UTC | 82.4 | 71.6 | 220° 7 kt | 1010.2 | ||
| 21:35 UTC | 84.2 | 71.6 | 250° 10 kt | 1009.8 | ||
| 21:55 UTC | 84.2 | 73.4 | 290° 12 kt | 1009.8 | ||
| 22:15 UTC | 82.4 | 71.6 | 270° 13 kt | 1009.8 | ||
| 22:35 UTC | 82.4 | 71.6 | 270° 12 kt | 1010.2 | ||
| 22:55 UTC | 82.4 | 71.6 | 280° 9 kt | 1009.8 | ||
| 23:15 UTC | 82.4 | 71.6 | 300° 11 kt | 1010.2 | ||
| 23:35 UTC | 84.2 | 69.8 | 300° 9 kt | 1010.5 | ||
| 23:55 UTC | 82.4 | 69.8 | 300° 8 kt | 1010.2 | ||
| 00:15 UTC | 84.2 | 69.8 | 320° 9 kt | 1009.8 | ||
| 00:35 UTC | 84.2 | 69.8 | 330° 9 kt | 1010.2 | ||
| 00:55 UTC | 82.4 | 69.8 | 340° 6 kt | 1010.5 |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Fargo/Grand Forks radar (KMVX), 82 km away, was scanning. The volume nearest the touchdown began at 23:03 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 2001 tornado in North DakotaEvery tornado in North Dakota since 1950Warnings in force in North Dakota nowThe forecast where you are
The other tornadoes of July 18, 2001
25 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| July 18 | 4:34 PM CDT | F0 | Pembina, ND | 0.5 | 25 | |||
| July 18 | 5:00 PM CDT | F0 | Kittson, MN | 0.5 | 25 | |||
| July 18 | 5:55 PM CDT | F0 | Nelson, ND | 0.5 | 25 | |||
| July 18 | 5:57 PM CDT | F0 | Griggs, ND | 0.5 | 25 | |||
| July 18 | 6:04 PM CDT | F0 | Griggs, ND | 0.5 | 25 | |||
| July 18 | 6:09 PM CDT | F0 | Griggs, ND | 1.0 | 25 | |||
| July 18 | 6:23 PM CDT | F0 | Nelson, ND | 0.5 | 100 | |||
| July 18 | 6:25 PM CDT | F0 | Nelson, ND | 0.5 | 100 | |||
| July 18 | 6:35 PM CDT | F0 | Griggs, ND | 0.5 | 25 | |||
| July 18 | 6:58 PM CDT | F1 | Thayer, NE | 2.0 | 40 | $50,000 | ||
| July 18 | 7:00 PM CDT | F0 | Steele, ND | 0.5 | 25 | |||
| July 18 | 7:00 PM CDT | F0 | Nelson, ND | 0.5 | 25 | |||
| July 18 | 7:04 PM CDT | F0 | Nelson, ND | 0.5 | 25 | |||
| July 18 | 7:20 PM CDT | F0 | Nelson, ND | 0.5 | 25 | |||
| July 18 | 8:00 PM CDT | F0 | Steele, ND | 0.5 | 25 | |||
| July 18 | 8:00 PM CDT | F0 | Griggs, ND | 0.5 | 25 | |||
| July 18 | 8:05 PM CDT | F0 | Lake of the Woods, MN | 0.5 | 25 | |||
| July 18 | 8:30 PM CDT | F0 | McIntosh, ND | 3.0 | 40 | |||
| July 18 | 8:40 PM CDT | F2 | Edmunds, SD | 1.0 | 100 | |||
| July 18 | 8:45 PM CDT | F0 | McPherson, SD | 0.5 | 50 | |||
| July 18 | 8:53 PM CDT | F1 | LaMoure, ND | 3.0 | 50 | |||
| July 18 | 9:05 PM CDT | F1 | Marshall, MN | 1.0 | 50 | |||
| July 18 | 9:19 PM CDT | F0 | Faulk, SD | 0.3 | 25 | |||
| July 18 | 12:04 AM CDT | F0 | Grand Forks, ND | 0.5 | 25 | |||
| July 18 | 12:14 AM CDT | F0 | Grand Forks, ND | 1.0 | 25 |
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.