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.

Tornado in TOWNER, NORTH DAKOTA
From 09-AUG-21 18:16:00 to 09-AUG-21 18:23:00 (CST-6)
Location: NEWVILLE
Tornado F-scale: EF1
Property damage: 2.00K
Crop damage: 2.00K
Reported by: Trained Spotter

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.

Tornado in STEELE, NORTH DAKOTA
From 09-AUG-21 20:20:00 to 09-AUG-21 20:28:00 (CST-6)
Location: SHARON
Tornado F-scale: EF2
Property damage: 150.00K
Crop damage: 4.00K
Reported by: NWS Storm Survey

This tornado tracked from far northeast Sharon Township across far northwest Westfield Township. A tornado Debris Signature was evident on KMVX radar. The tornado completely dismantled and destroyed a barn at one farmstead. It also snapped or uprooted numerous spruce, ash, cottonwood, and willow trees at various locations along its path.

Tornado in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 20:42:00 to 09-AUG-21 20:43:00 (CST-6)
Location: KEMPTON
Tornado F-scale: EF1
Property damage: 1.00K
Reported by: NWS Storm Survey

A few cottonwood trees were snapped or uprooted in a shelterbelt. A brief tornado touchdown is expected based on radar imagery.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 21:45:00 to 09-AUG-21 21:45:00 (CST-6)
Location: BOLACK
Magnitude: 61.00 EG
Property damage: 40.00K
Reported by: NWS Storm Survey

Metal roof was torn from a business along Highway 2. Time was estimated based on radar and nearby sensor observations.

Hail in PEMBINA, NORTH DAKOTA
From 09-AUG-21 20:03:00 to 09-AUG-21 20:03:00 (CST-6)
Location: WALHALLA
Magnitude: 1.00 
Reported by: Public

Funnel Cloud in STEELE, NORTH DAKOTA
From 09-AUG-21 20:09:00 to 09-AUG-21 20:09:00 (CST-6)
Location: SHARON
Reported by: Law Enforcement

A well-developed wall cloud and funnel was reported to the Steele County Sheriffs office after it passed over a farmstead.

Thunderstorm Wind in NELSON, NORTH DAKOTA
From 09-AUG-21 20:23:00 to 09-AUG-21 20:23:00 (CST-6)
Location: ANETA GEHRKE ARPT
Magnitude: 61.00 EG
Reported by: NWS Storm Survey

Spruce trees partially uprooted in a shelterbelt. Time is estimated based on radar.

Funnel Cloud in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 20:28:00 to 09-AUG-21 20:28:00 (CST-6)
Location: LOGAN CENTER
Reported by: Trained Spotter

A well-developed wall cloud and a funnel cloud were reported by a storm chaser and trained spotter.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 20:31:00 to 09-AUG-21 20:31:00 (CST-6)
Location: LOGAN CENTER
Magnitude: 58.00 MG
Reported by: Mesonet

Peak wind measured by an NDAWN station at the 10-meter height.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 20:36:00 to 09-AUG-21 20:36:00 (CST-6)
Location: LOGAN CENTER
Magnitude: 61.00 EG
Reported by: Public

A 12-inch diameter cottonwood branch was reported snapped. Pea-sized hail was also reported. Report received via social media, time estimated from radar.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 20:45:00 to 09-AUG-21 20:45:00 (CST-6)
Location: NORTHWOOD ARPT
Magnitude: 61.00 EG
Reported by: NWS Storm Survey

A poplar tree was blown down along with several large tree branches and limbs at the Northwood Golf Course. Likely caused by the rear flank downdraft from a supercell. Time estimated based on radar.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 21:09:00 to 09-AUG-21 21:09:00 (CST-6)
Location: EMERADO
Magnitude: 52.00 EG
Reported by: NWS Storm Survey

A couple of cottonwood trees were blown down; time was estimated based on radar.

Hail in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 21:30:00 to 09-AUG-21 21:30:00 (CST-6)
Location: BOLACK
Magnitude: 1.00 
Reported by: Public

A public report of hail was relayed via social media.

Hail in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 21:30:00 to 09-AUG-21 21:30:00 (CST-6)
Location: GRAND FORKS
Magnitude: 1.00 
Reported by: Public

A public report of hail was relayed via social media.

Funnel Cloud in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 21:35:00 to 09-AUG-21 21:35:00 (CST-6)
Location: MERRIFIELD
Reported by: Trained Spotter

A trained spotter reported a well-developed wall cloud, along with a brief funnel cloud. The wall cloud became rain-wrapped.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 21:37:00 to 09-AUG-21 21:37:00 (CST-6)
Location: (GFK)GRAND FORKS INT
Magnitude: 60.00 MG
Reported by: ASOS

Peak wind was measured by the KGFK ASOS at the Grand Forks International Airport.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 21:38:00 to 09-AUG-21 21:38:00 (CST-6)
Location: GRAND FORKS
Magnitude: 52.00 MG
Reported by: Public

Peak wind was measured by the UND Clifford Hall Anemometer.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 21:42:00 to 09-AUG-21 21:42:00 (CST-6)
Location: GRAND FORKS
Magnitude: 52.00 EG
Reported by: Trained Spotter

Numerous large branches and limbs down along Belmont Rd, south of 27th.

Thunderstorm Wind in TRAILL, NORTH DAKOTA
From 09-AUG-21 21:46:00 to 09-AUG-21 21:46:00 (CST-6)
Location: REYNOLDS
Magnitude: 52.00 EG
Reported by: Public

A few 3 to 5-inch tree branches were down in shelterbelts across northern Stavanger Township. Time estimated based on radar.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 21:47:00 to 09-AUG-21 21:47:00 (CST-6)
Location: REYNOLDS
Magnitude: 52.00 EG
Reported by: Public

Large, 4 to 6-inch diameter, tree branches were broken across a farmstead.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 09-AUG-21 21:48:00 to 09-AUG-21 21:48:00 (CST-6)
Location: BOLACK
Magnitude: 54.00 MG
Reported by: Mesonet

The peak wind was measured at a North Dakota DOT RWIS station.

Hail in BENSON, NORTH DAKOTA
From 09-AUG-21 16:55:00 to 09-AUG-21 16:55:00 (CST-6)
Location: HESPER
Magnitude: 1.00 
Reported by: Public

Received a public report of dime to quarter-sized hail that fell off and on for about 5 minutes.

Hail in EDDY, NORTH DAKOTA
From 09-AUG-21 17:21:00 to 09-AUG-21 17:21:00 (CST-6)
Location: NEW ROCKFORD
Magnitude: 1.50 
Reported by: Public

Hail in TOWNER, NORTH DAKOTA
From 09-AUG-21 17:25:00 to 09-AUG-21 17:25:00 (CST-6)
Location: ZION
Magnitude: 1.00 
Reported by: Public

Dime to quarter-sized hail nearly covered the ground across southeastern Zion Township.

Thunderstorm Wind in EDDY, NORTH DAKOTA
From 09-AUG-21 17:46:00 to 09-AUG-21 17:46:00 (CST-6)
Location: DUNDAS SIDING
Magnitude: 61.00 EG
Reported by: Public

Damaging winds combined with dime to quarter-sized hail to break windows across town. Time was estimated by radar.

Hail in EDDY, NORTH DAKOTA
From 09-AUG-21 18:01:00 to 09-AUG-21 18:01:00 (CST-6)
Location: BRANTFORD
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in RAMSEY, NORTH DAKOTA
From 09-AUG-21 18:27:00 to 09-AUG-21 18:27:00 (CST-6)
Location: STARKWEATHER
Magnitude: 1.25 
Reported by: Public

Quarter to half-dollar sized hail lasted for a few minutes.

Hail in EDDY, NORTH DAKOTA
From 09-AUG-21 18:30:00 to 09-AUG-21 18:30:00 (CST-6)
Location: HAMAR
Magnitude: 1.25 
Reported by: Trained Spotter

Trained spotter reported very heavy rain along with quarter to half-dollar sized hail.

Hail in NELSON, NORTH DAKOTA
From 09-AUG-21 19:00:00 to 09-AUG-21 19:00:00 (CST-6)
Location: PEKIN
Magnitude: 1.25 
Reported by: Public

Hail was reported between Tolna and Pekin, ranging from nickel to quarter-sized.

Hail in EDDY, NORTH DAKOTA
From 09-AUG-21 19:10:00 to 09-AUG-21 19:10:00 (CST-6)
Location: BRANTFORD
Magnitude: 1.50 
Reported by: Public

Received a public report of large hail and heavy rain.

Hail in CAVALIER, NORTH DAKOTA
From 09-AUG-21 19:18:00 to 09-AUG-21 19:18:00 (CST-6)
Location: LANGDON
Magnitude: 1.00 
Reported by: Public

Received a public report of dime to quarter-sized hail.

Hail in CAVALIER, NORTH DAKOTA
From 09-AUG-21 19:22:00 to 09-AUG-21 19:22:00 (CST-6)
Location: LANGDON
Magnitude: 1.50 
Reported by: Public

Very heavy rain and strong winds occurred, along with hail up to the size of ping pong balls.

Thunderstorm Wind in NELSON, NORTH DAKOTA
From 09-AUG-21 19:24:00 to 09-AUG-21 19:34:00 (CST-6)
Location: MC VILLE ARPT
Magnitude: 61.00 EG
Reported by: Public

Several large, 4 to 6 inch, tree branches were snapped around a farmstead.

Hail in GRIGGS, NORTH DAKOTA
From 09-AUG-21 19:26:00 to 09-AUG-21 19:26:00 (CST-6)
Location: BINFORD
Magnitude: 1.75 
Reported by: Public

Photos and reports received on social media showing mostly golf ball-sized hail, with a few larger pieces.

Thunderstorm Wind in GRIGGS, NORTH DAKOTA
From 09-AUG-21 19:27:00 to 09-AUG-21 19:37:00 (CST-6)
Location: MOSE
Magnitude: 52.00 EG
Reported by: Public

Received a public report of a few large tree branches broken near Red Willow Lake.

Funnel Cloud in GRIGGS, NORTH DAKOTA
From 09-AUG-21 19:28:00 to 09-AUG-21 19:28:00 (CST-6)
Location: BINFORD
Reported by: Law Enforcement

Law enforcement spotted a large wall cloud moving toward Binford, with a possible funnel cloud.

Tornado in GRIGGS, NORTH DAKOTA
From 09-AUG-21 19:34:00 to 09-AUG-21 19:35:00 (CST-6)
Location: JESSIE
Tornado F-scale: EF0
Reported by: Storm Chaser

A brief touchdown was noted and recorded on video between 834 and 835 pm CDT. The touchdown occurred over an open field as the storm quickly became ran wrapped. Additional brief touchdown may have occurred later in the east-northeastward path.

Hail in GRIGGS, NORTH DAKOTA
From 09-AUG-21 19:35:00 to 09-AUG-21 19:35:00 (CST-6)
Location: BINFORD
Magnitude: 2.50 
Reported by: Public

A photo and report of 2.5-inch hail was received via social media.

Hail in GRIGGS, NORTH DAKOTA
From 09-AUG-21 19:35:00 to 09-AUG-21 19:35:00 (CST-6)
Location: BINFORD
Magnitude: 2.75 
Reported by: Public

Photo and report received via social media. Hail was larger than the diameter of a soda can. Time estimated based on radar.