Tornadoes · United States · North Dakota · 2020
EF0 tornado, Volga to Hillsboro, North Dakota, August 9, 2020
From Volga to Hillsboro, this EF0 tornado ran 2.0 miles across Traill County on August 9, 2020, touching down at 2:40 PM CDT and reaching 40 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 mphthis tornado
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.
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
- August 9, 2020
- Touchdown
- 2:40 PM CDT (19:40 UTC)
- Lifted
- 2:46 PM CDT (19:46 UTC)
- On the ground
- 6 minutes
- Path length
- 2.0 miles (3.2 km)
- Path width
- 40 yards (37 m)
- Deaths
- 0
- Injuries
- 0
- County
- Traill County
- Touchdown point
- 47.400, -97.170
- Lift-off point
- 47.400, -97.134
- Record number
- 2008091340-01
What the Weather Service recorded
A cold front moved across eastern North Dakota and the northwest quarter of Minnesota on Sunday, August 9th. Abundant moisture remained in place, with dew points in the upper 60s to lower 70s. Thunderstorms formed across the area, producing large hail, damaging wind gusts, and tornadoes.
The tornado snapped branches and trees in several shelterbelts along its path. Peak winds were estimated at 70 mph.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
4 minutes of warning. NWS FGF issued a tornado warning for this county at 19:36 UTC, 4 minutes before the tornado touched down, in force until 20:04 UTC.
The county was under a severe thunderstorm watch, issued at 17:52 UTC and running to 22:15 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 17:52 UTC | 22:15 UTC | Severe Thunderstorm Watch | FGF |
| 19:10 UTC | 20:15 UTC | Severe Thunderstorm Warning | FGF |
| 19:36 UTC | 20:04 UTC | Tornado Warning | FGF |
| 19:52 UTC | 20:45 UTC | Severe Thunderstorm Warning | FGF |
| 20:12 UTC | 20:37 UTC | Severe Thunderstorm Warning | FGF |
| 20:53 UTC | 21:24 UTC | Severe Thunderstorm 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 Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 16:16 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
7.7 hours before the tornado, 278 km from the path. August 9, 2020.
- Mixed-layer CAPE
- 2140 J/kg
- Mixed-layer CIN
- -174 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 843 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 95 m²/s²
- 0-3 km storm-relative helicity
- 127 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.5
- 0-3 km lapse rate
- 3.4 K/km
Bismarck Municip, ND (KBIS), 00:00Z
4.3 hours after it, 278 km from the path. August 10, 2020.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -88271 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 2738 m above ground
- 0-6 km bulk shear
- 46 kt
- 0-1 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- -79 m²/s²
- 0-3 km storm-relative helicity
- -104 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 7.1 K/km
The surface observations
Fargo (FAR), 59 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 17:40 UTC | 180° 11 kt | 1007.5 | ||||
| 17:45 UTC | 180° 11 kt | 1007.5 | ||||
| 17:50 UTC | 190° 11 kt | 1007.5 | ||||
| 17:53 UTC | 78 | 68 | 190° 10 kt | 1007.5 | ||
| 17:55 UTC | 180° 11 kt | 1007.5 | ||||
| 18:00 UTC | 180° 13 kt | 1007.5 | ||||
| 18:05 UTC | 190° 13 kt | 1007.5 | ||||
| 18:15 UTC | 170° 11 kt | 1007.5 | ||||
| 18:20 UTC | 180° 11 kt | 1007.5 | ||||
| 18:25 UTC | 190° 14 kt | 19 | 1007.1 | |||
| 18:30 UTC | 200° 11 kt | 1007.1 | ||||
| 18:35 UTC | 190° 14 kt | 1006.8 | ||||
| 18:40 UTC | 170° 11 kt | 18 | 1006.4 | |||
| 18:45 UTC | 180° 11 kt | 1006.4 | ||||
| 18:50 UTC | 190° 15 kt | 1006.8 | ||||
| 18:53 UTC | 82 | 70 | 180° 16 kt | 20 | 1006.8 | |
| 18:55 UTC | 180° 16 kt | 1007.1 | ||||
| 19:00 UTC | 180° 10 kt | 15 | 1007.1 | |||
| 19:05 UTC | 190° 13 kt | 1007.1 | ||||
| 19:10 UTC | 200° 13 kt | 1007.1 | ||||
| 19:15 UTC | 180° 13 kt | 1007.1 | ||||
| 19:20 UTC | 170° 11 kt | 1006.4 | ||||
| 19:25 UTC | 170° 15 kt | 1006.1 | -RA | |||
| 19:30 UTC | 160° 11 kt | 17 | 1005.8 | -RA | ||
| 19:35 UTC | 170° 14 kt | 1005.8 | -RA | |||
| 19:40 UTC | 170° 16 kt | 21 | 1006.1 | |||
| 19:45 UTC | 180° 13 kt | 18 | 1006.8 | |||
| 19:50 UTC | 180° 15 kt | 1006.8 | ||||
| 19:53 UTC | 80 | 69 | 180° 14 kt | 21 | 1006.4 | |
| 19:55 UTC | 15 kt | 1006.1 | ||||
| 20:00 UTC | 180° 11 kt | 1006.4 | ||||
| 20:05 UTC | 170° 13 kt | 1006.1 | ||||
| 20:10 UTC | 180° 11 kt | 1006.1 | ||||
| 20:15 UTC | 170° 11 kt | 1005.4 | ||||
| 20:20 UTC | 160° 10 kt | 15 | 1005.8 | |||
| 20:25 UTC | 180° 15 kt | 1006.1 | -RA | |||
| 20:26 UTC | 79 | 68 | 180° 14 kt | 20 | 1006.1 | VCTS -RA |
| 20:30 UTC | 180° 13 kt | 1006.1 | -RA | |||
| 20:35 UTC | 77 | 69 | 200° 14 kt | 22 | 1007.1 | -TSRA |
| 20:40 UTC | 11 kt | 1007.8 | +RA | |||
| 20:41 UTC | 75 | 70 | 280° 14 kt | 24 | 1008.1 | +TSRA |
| 20:45 UTC | 15 kt | 1008.5 | +RA BR | |||
| 20:46 UTC | 71 | 69 | 300° 16 kt | 25 | 1008.5 | +TSRA BR |
| 20:50 UTC | 15 kt | 1008.1 | +RA BR | |||
| 20:53 UTC | 69 | 66 | 320° 9 kt | 28 | 1007.5 | +TSRA BR |
| 20:55 UTC | 310° 8 kt | 1007.5 | +RA BR | |||
| 20:59 UTC | 69 | 65 | 320° 8 kt | 1007.1 | -TSRA BR | |
| 21:00 UTC | 330° 9 kt | 1007.1 | -RA BR | |||
| 21:05 UTC | 320° 2 kt | 1007.5 | -RA | |||
| 21:08 UTC | 69 | 64 | 4 kt | 1007.5 | -TSRA | |
| 21:10 UTC | 220° 2 kt | 1007.5 | -RA | |||
| 21:15 UTC | 270° 4 kt | 1008.1 | -RA | |||
| 21:20 UTC | 310° 4 kt | 1008.5 | -RA | |||
| 21:25 UTC | 270° 2 kt | 1008.5 | -RA | |||
| 21:28 UTC | 69 | 66 | 3 kt | 1008.5 | VCTS -RA | |
| 21:30 UTC | 330° 2 kt | 1008.5 | -RA | |||
| 21:35 UTC | 340° 5 kt | 1008.5 | -RA |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Fargo/Grand Forks radar (KMVX), 19 km away, was scanning. The volume nearest the touchdown began at 19:39 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 |
|---|---|---|---|---|
| 19:20 UTC | HAIL 1.25 | 2 Ne Thompson | Grand Forks, ND | HAIL ON INTERSTATE 29, JUST NORTH OF THE THOMPSON EXIT, AROUND MP131. |
| 19:28 UTC | FUNNEL CLOUD | 4 Nw Blanchard | Traill, ND | TWO FUNNELS VIEWED FROM TWO STORMS NORTHWEST OF BLANCHARD. BOTH WERE LESS THAN A QUARTER OF THE WAY DOWN. ORIGINAL REPORT VIA 911 CALL CENTER. PHOTO POSTED TO SOCIAL MEDIA. |
| 19:28 UTC | FUNNEL CLOUD | 4 Nw Blanchard | Traill, ND | TWO FUNNELS VIEWED FROM TWO STORMS NORTHWEST OF BLANCHARD. BOTH WERE LESS THAN A QUARTER OF THE WAY DOWN. ORIGINAL REPORT VIA 911 CALL CENTER. PHOTO POSTED TO SOCIAL MEDIA. |
| 19:45 UTC | FUNNEL CLOUD | 4 W Hillsboro | Traill, ND | PHOTO,REPORT,AND TIME POSTED VIA SOCIAL MEDIA. FUNNEL VERY CLOSE TO TOUCHDOWN. |
| 19:45 UTC | FUNNEL CLOUD | 4 W Hillsboro | Traill, ND | PHOTO,REPORT,AND TIME POSTED VIA SOCIAL MEDIA. FUNNEL VERY CLOSE TO TOUCHDOWN. |
| 19:45 UTC | TORNADO 0 | 4 W Hillsboro | Traill, ND | PHOTO, REPORT, AND TIME POSTED VIA SOCIAL MEDIA. MULTIPLE REPORTS OF A BRIEF TOUCHDOWN. POSSIBLE TRACK LESS THAN ONE QUATER MILE. PEAK WINDS ESTIMATED TO 70 MPH. MAXIMUM WIDTH TO 30 YARDS. |
| 19:57 UTC | FUNNEL CLOUD | 6 Wnw Halstad | Traill, ND | PERSISTENT WALL CLOUDS WITH SMALL FUNNEL LOWERING. VIEWED TO NORTH FROM HIGHWAY 200. PHOTO AND REPORT POSTED VIA SOCIAL MEDIA. |
| 19:57 UTC | FUNNEL CLOUD | 6 Wnw Halstad | Traill, ND | PERSISTENT WALL CLOUDS WITH SMALL FUNNEL LOWERING. VIEWED TO NORTH FROM HIGHWAY 200. PHOTO AND REPORT POSTED VIA SOCIAL MEDIA. |
| 20:30 UTC | HAIL 0.88 | 2 Nnw Harwood | Cass, ND | WINDS REPORTED AS BEING FRISKY. |
| 20:30 UTC | HAIL 0.88 | 2 Nnw Harwood | Cass, ND | WINDS REPORTED AS BEING FRISKY. |
| 20:34 UTC | TSTM WND GST 48 | Prosper | Cass, ND | PEAK WINDS MEASURED AT A PERSONAL WEATHER STATION. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2020 tornado in North DakotaEvery tornado in North Dakota since 1950Warnings in force in North Dakota nowThe forecast where you are
The other tornadoes of August 9, 2020
12 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| August 9 | 11:58 AM CDT | EF0 | Cavalier, ND | 0.3 | 40 | |||
| August 9 | 2:02 PM CDT | EF1 | LaMoure, ND | 0.9 | 100 | $225,000 | ||
| August 9 | 2:13 PM CDT | Unrated | LaMoure, ND | 2.2 | 100 | |||
| August 9 | 2:13 PM CDT | EF1 | Pennington, MN | 22.0 | 200 | |||
| August 9 | 2:17 PM CDT | EF1 | Barnes, ND | 2.9 | 150 | |||
| August 9 | 2:19 PM CDT | Unrated | LaMoure, ND | 0.3 | 50 | |||
| August 9 | 3:20 PM CDT | EF1 | Beltrami, MN | 0.3 | 100 | |||
| August 9 | 6:15 PM EDT | EF0 | Manatee, FL | 0.2 | 100 | $20,000 | ||
| August 9 | 7:44 PM CDT | EF1 | Vilas, WI | 6.2 | 400 | |||
| August 9 | 8:28 PM CDT | EF1 | Vilas, WI | 5.9 | 250 | |||
| August 9 | 9:12 PM CDT | EF1 | Iron, WI to MI | 4.6 | 250 | $70,000 | ||
| August 9 | 9:56 PM CDT | EF1 | Iron, MI | 3.8 | 250 | $100,000 |
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.