Tornadoes · United States · North Dakota · 2021

EF1 tornado, Newville, North Dakota, August 9, 2021

This EF1 tornado ran 5.0 miles across Towner County on August 9, 2021, touching down at 7:16 PM CDT and reaching 200 yards wide. It killed nobody, and did $2,000 of property damage.

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 mph

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

  2. EF186 to 110 mphthis tornado

    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
EF1
Date
August 9, 2021
Touchdown
7:16 PM CDT (00:16 UTC)
Lifted
7:23 PM CDT (00:23 UTC)
On the ground
7 minutes
Path length
5.0 miles (8.0 km)
Path width
200 yards (183 m)
Deaths
0
Injuries
0
Property damage
$2,000
Crop damage
$2,000
County
Towner County
Touchdown point
48.450, -98.990
Lift-off point
48.510, -98.930
Record number
2108091816-01

What the Weather Service recorded

Severe thunderstorms formed during the late afternoon and early evening, extending into the overnight period. Damaging wind gusts, large hail, and tornadoes were all reported through the course of the event.

This tornado tracked from northeast Coolin Township into east-central Klingstrup Township. It snapped or uprooted several large cottonwood trees at farmsteads and shelterbelts along its path.

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 00:11 UTC, 5 minutes before the tornado touched down, in force until 00:45 UTC.

The county was under a severe thunderstorm watch, issued at 21:03 UTC and running to 04:00 UTC.

Issued (UTC)ExpiredProductOffice
21:03 UTC04:00 UTCSevere Thunderstorm WatchFGF
23:12 UTC00:15 UTCSevere Thunderstorm WarningFGF
00:04 UTC01:00 UTCSevere Thunderstorm WarningFGF
00:11 UTC00:45 UTCTornado WarningFGF

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 19:54 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), 00:00Z

0.3 hours before the tornado, 231 km from the path. August 10, 2021.

Skew-T log-pSkew-T log-p diagram, Bismarck Municip, ND at 00:00Z on 2021-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 296 joules per kilogram, CIN -462, lifted condensation level 1238 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Bismarck Municip, ND at 00:00Z on 2021-08-10The 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 -40 square meters per square second, 0 to 6 km bulk shear 56 knots.1939587897Sfc1 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
296 J/kg
Mixed-layer CIN
-462 J/kg
Surface CAPE
673 J/kg
Mixed-layer LCL
1238 m above ground
0-6 km bulk shear
56 kt
0-1 km bulk shear
9 kt
0-1 km storm-relative helicity
-40 m²/s²
0-3 km storm-relative helicity
31 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2
0-3 km lapse rate
5.8 K/km

Open this sounding in Storm Lab

Bismarck Municip, ND (KBIS), 12:00Z

11.7 hours after it, 231 km from the path. August 10, 2021.

Skew-T log-pSkew-T log-p diagram, Bismarck Municip, ND at 12:00Z on 2021-08-10Temperature 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 -87318, lifted condensation level 1811 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Bismarck Municip, ND at 12:00Z on 2021-08-10The 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 93 square meters per square second, 0 to 6 km bulk shear 71 knots.1939587897Sfc1 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
-87318 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1811 m above ground
0-6 km bulk shear
71 kt
0-1 km bulk shear
26 kt
0-1 km storm-relative helicity
93 m²/s²
0-3 km storm-relative helicity
122 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.6 K/km

Open this sounding in Storm Lab

The radar

The Minot AFB radar (KMBX), 141 km away, was scanning. The volume nearest the touchdown began at 00:15 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
23:25 UTCHAIL 18 W CandoTowner, NDDIME TO QUARTER SIZED HAIL REPORTED ACROSS SOUTHEASTERN ZION TOWNSHIP. NEARLY COVERED THE GROUND.
00:16 UTCTORNADO 15 W StarkweatherTowner, NDA TORNADO TOUCHED DOWN IN NORTHEAST COOLIN TOWNSHIP AND TRACKED INTERMITTENTLY TO THE NORTHEAST FOR ROUGHLY 4 MILES TO AROUND 4 NW STARKWEATHER IN WESTCENTRAL KLINGSTRUP TOWNSHIP /RAMSEY COUNTY/ BY 723 PM CDT. THE TORNAD
00:27 UTCHAIL 1.252 S StarkweatherRamsey, NDQUARTER TO HALF DOLLAR SIZED HAIL FOR A FEW MINUTES.
00:40 UTCTSTM WND GST 501 Se HampdenRamsey, NDPEAK WIND MEASURED AT A RAWS STATION. TIME ESTIMATED BASED ON RADAR.
00:45 UTCTSTM WND GST 501 Se HampdenRamsey, NDPEAK WIND MEASURED AT A RAWS STATION. TIME ESTIMATED BASED ON RADAR.
01:18 UTCHAIL 16 S LangdonCavalier, NDA FEW DIME TO QUARTER SIZED HAIL.
01:22 UTCHAIL 1.53 Se LangdonCavalier, NDA FEW QUARTER TO PING PONG BALL SIZED HAIL IN VERY HEAVY RAIN AND STRONG WINDS.

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 North DakotaEvery tornado in North Dakota since 1950Warnings in force in North Dakota nowThe forecast where you are

The other tornadoes of August 9, 2021

19 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 92:52 PM CDTEF0Rock, WI3.225
August 94:35 PM CDTEF0DeKalb, IL0.120
August 94:44 PM CDTEF1DeKalb, IL1.880
August 94:45 PM CDTEF1McHenry, IL0.470
August 95:24 PM CDTEF1Kane, IL3.8100
August 95:28 PM CDTEF0DeKalb, IL6.850
August 96:03 PM CDTUnratedLee, IL1.375
August 96:13 PM CDTEF1DeKalb, IL1.5150
August 96:13 PM CDTUnratedBureau, IL0.05
August 96:26 PM CDTEF0DeKalb, IL0.220
August 96:28 PM CDTEF0Kane, IL3.9400
August 96:38 PM CDTUnratedKane, IL0.110
August 96:57 PM CDTEF1Bureau, IL3.0525
August 97:24 PM CDTUnratedBureau, IL1.1100
August 98:34 PM CDTEF0Griggs, ND0.350
August 99:20 PM CDTEF2Steele, ND2.9300$150,000
August 99:42 PM CDTEF1Grand Forks, ND1.1150$1,000
August 910:55 PM CDTEF1Polk, MN3.6200$120,000
August 911:05 PM CDTEF0Polk, MN2.2150$5,000

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.