On the morning of July 21st, a thunderstorm just north of the Canadian border moved southeast into Cavalier County, North Dakota, where it dropped large hail. This storm weakened for a few hours, but remained intact. The same storm re-intensified by mid afternoon over eastern Marshall County, Minnesota, and remained very strong until it reached the town of Saum, in Beltrami County, Minnesota. Meanwhile, temperatures by the afternoon of the 21st rose into the lower 90s, with dew points in the mid 60s to lower 70s. More strong thunderstorms moved into the Cooperstown, North Dakota, area, and tracked to the east-southeast. Then, during the early evening, a line of strong storms consolidated from near Bemidji to just east of Moorhead, Minnesota. This line of storms held together as it moved to the east-southeast. By late evening, more strong storms moved into the Devils Lake region, still tracking to the east-southeast. This area of storms continued to hold together, flaring up near Hunter, North Dakota, and near Pelican Rapids, Minnesota, where it produced several reports of strong winds.

Tornado in BELTRAMI, MINNESOTA
From 21-JUL-17 14:45:00 to 21-JUL-17 14:50:00 (CST-6)
Location: SAUM
Tornado F-scale: EF1
Property damage: 100.00K
Crop damage: 5.00K
Reported by: NWS Storm Survey

This tornado tracked eastward with numerous intermittent touchdowns along its roughly three mile track. Numerous trees were snapped and a couple of grain bins were toppled. Roof panels and walls were blown out of pole sheds and calving sheds were flipped. Insulation and roofing metal were strewn about. Peak winds were estimated at 95 mph.

Thunderstorm Wind in CLEARWATER, MINNESOTA
From 21-JUL-17 15:50:00 to 21-JUL-17 15:50:00 (CST-6)
Location: EBRO
Magnitude: 61.00 EG
Reported by: NWS Storm Survey

Numerous large pine, oak, and poplar trees and branches were blown down. The worst of the damage was across southern Popple and northern Falk townships.

Hail in MARSHALL, MINNESOTA
From 21-JUL-17 13:10:00 to 21-JUL-17 13:10:00 (CST-6)
Location: GRYGLA
Magnitude: 1.00 
Reported by: Public

The hail ranged from pea to quarter size.

Hail in BELTRAMI, MINNESOTA
From 21-JUL-17 14:40:00 to 21-JUL-17 14:40:00 (CST-6)
Location: SAUM
Magnitude: 1.00 
Reported by: Public

The hail was mostly pea to marble size.

Thunderstorm Wind in BELTRAMI, MINNESOTA
From 21-JUL-17 15:06:00 to 21-JUL-17 15:06:00 (CST-6)
Location: SHOOKS
Magnitude: 52.00 MG
Reported by: Mesonet

The wind gust was measured by a RWIS station.

Thunderstorm Wind in POLK, MINNESOTA
From 21-JUL-17 15:20:00 to 21-JUL-17 15:20:00 (CST-6)
Location: ERSKINE
Magnitude: 50.00 EG
Reported by: Broadcast Media

Numerous large branches were blown down around town.

Thunderstorm Wind in POLK, MINNESOTA
From 21-JUL-17 15:25:00 to 21-JUL-17 15:25:00 (CST-6)
Location: ERSKINE MUNI ARPT
Magnitude: 61.00 EG
Reported by: Public

At least six to eight large trees were blown down in a yard. One of the trees was uprooted.

Thunderstorm Wind in POLK, MINNESOTA
From 21-JUL-17 15:45:00 to 21-JUL-17 15:45:00 (CST-6)
Location: LENGBY
Magnitude: 55.00 EG
Reported by: Public

Large branches were blown down and power was knocked out.

Thunderstorm Wind in MAHNOMEN, MINNESOTA
From 21-JUL-17 15:46:00 to 21-JUL-17 15:46:00 (CST-6)
Location: MAHKONCE
Magnitude: 52.00 EG
Reported by: Trained Spotter

The strong winds damaged trees in the area.

Thunderstorm Wind in CLEARWATER, MINNESOTA
From 21-JUL-17 16:00:00 to 21-JUL-17 16:00:00 (CST-6)
Location: BAGLEY
Magnitude: 61.00 EG
Reported by: Public

Numerous trees were blown down.

Hail in CLEARWATER, MINNESOTA
From 21-JUL-17 16:00:00 to 21-JUL-17 16:00:00 (CST-6)
Location: BAGLEY
Magnitude: 0.88 
Reported by: Public

The hail varied in size from pea to nickel.

Thunderstorm Wind in CLEARWATER, MINNESOTA
From 21-JUL-17 16:00:00 to 21-JUL-17 16:00:00 (CST-6)
Location: BAGLEY
Magnitude: 61.00 EG
Reported by: Public

Numerous large pine, oak, and poplar trees and branches and power lines were blown down in the Bagley area. The worst damage was in southern Copley Township.

Hail in CLEARWATER, MINNESOTA
From 21-JUL-17 16:00:00 to 21-JUL-17 16:00:00 (CST-6)
Location: EBRO
Magnitude: 1.25 
Reported by: Public

The hail was mostly dime to nickel size.

Thunderstorm Wind in CLEARWATER, MINNESOTA
From 21-JUL-17 16:01:00 to 21-JUL-17 16:01:00 (CST-6)
Location: BAGLEY MUNI ARPT
Magnitude: 78.00 EG
Reported by: Trained Spotter

The strong winds blew out a window on a house and broke down numerous large tree branches. Pine, oak, and poplar trees were snapped or uprooted across Nora Township. Downed pine trees were left lying across highway 92 for about six miles of its north-south length.

Hail in CLEARWATER, MINNESOTA
From 21-JUL-17 16:04:00 to 21-JUL-17 16:04:00 (CST-6)
Location: BAGLEY MUNI ARPT
Magnitude: 2.00 
Reported by: Trained Spotter

Thunderstorm Wind in BELTRAMI, MINNESOTA
From 21-JUL-17 16:16:00 to 21-JUL-17 16:16:00 (CST-6)
Location: SOLWAY
Magnitude: 61.00 EG
Reported by: Public

A few trees were snapped with branches scattered about.

Thunderstorm Wind in HUBBARD, MINNESOTA
From 21-JUL-17 16:22:00 to 21-JUL-17 16:22:00 (CST-6)
Location: BECIDA
Magnitude: 65.00 EG
Reported by: Trained Spotter

Metal roofing panels were torn off a barn.

Thunderstorm Wind in BELTRAMI, MINNESOTA
From 21-JUL-17 16:27:00 to 21-JUL-17 16:27:00 (CST-6)
Location: WILTON
Magnitude: 65.00 EG
Reported by: NWS Storm Survey

Numerous large tree branches were blown down across southern Eckles Township.

Tornado in CLAY, MINNESOTA
From 21-JUL-17 16:34:00 to 21-JUL-17 16:35:00 (CST-6)
Location: CRAWFORD
Tornado F-scale: EF0
Reported by: Storm Chaser

A weak tornado was observed over largely open farmland just north of Interstate 94 in extreme southeast Glyndon Township. Peak winds were estimated at 75 mph.

Thunderstorm Wind in BELTRAMI, MINNESOTA
From 21-JUL-17 16:37:00 to 21-JUL-17 16:37:00 (CST-6)
Location: (BJI)BEMIDJI ARPT
Magnitude: 54.00 MG
Reported by: Mesonet

The wind gust was measured at the Bemidji RAWS station.

Thunderstorm Wind in BELTRAMI, MINNESOTA
From 21-JUL-17 16:40:00 to 21-JUL-17 16:40:00 (CST-6)
Location: BIRCHMONT
Magnitude: 50.00 EG
Reported by: Emergency Manager

Large tree branches were blown down and the power was out.

Thunderstorm Wind in BELTRAMI, MINNESOTA
From 21-JUL-17 16:40:00 to 21-JUL-17 16:40:00 (CST-6)
Location: FARLEY
Magnitude: 56.00 EG
Reported by: Public

Several trees and numerous branches were blown down.

Thunderstorm Wind in BELTRAMI, MINNESOTA
From 21-JUL-17 16:40:00 to 21-JUL-17 16:40:00 (CST-6)
Location: BIRCHMONT
Magnitude: 56.00 EG
Reported by: Public

Several trees were blown down. Some docks, boats, and boat lifts were flipped on Lake Movil.

Thunderstorm Wind in HUBBARD, MINNESOTA
From 21-JUL-17 16:42:00 to 21-JUL-17 16:42:00 (CST-6)
Location: LAPORTE
Magnitude: 56.00 EG
Reported by: Public

A few large trees were blown down around Garfield Lake.

Hail in BECKER, MINNESOTA
From 21-JUL-17 16:45:00 to 21-JUL-17 16:45:00 (CST-6)
Location: RICHWOOD
Magnitude: 1.00 
Reported by: Public

The hail was accompanied by very heavy rain.

Hail in HUBBARD, MINNESOTA
From 21-JUL-17 16:50:00 to 21-JUL-17 16:50:00 (CST-6)
Location: BENEDICT MORRILL ARP
Magnitude: 1.00 
Reported by: Trained Spotter

The hail was accompanied by very strong winds. This also resulted in large branches being blown down around Benedict Lake.

Thunderstorm Wind in BELTRAMI, MINNESOTA
From 21-JUL-17 17:00:00 to 21-JUL-17 17:00:00 (CST-6)
Location: LAVINIA
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Large oak tree was blown over onto a house near Lake Andrusia.

Hail in OTTER TAIL, MINNESOTA
From 21-JUL-17 18:10:00 to 21-JUL-17 18:10:00 (CST-6)
Location: ROTHSAY
Magnitude: 1.25 
Reported by: Public

Quarter to half dollar sized hail fell with very heavy rain.

Thunderstorm Wind in BELTRAMI, MINNESOTA
From 21-JUL-17 16:45:00 to 21-JUL-17 16:45:00 (CST-6)
Location: TURTLE RIVER
Magnitude: 56.00 EG
Reported by: Public

Several large trees were snapped or uprooted.

Hail in CLAY, MINNESOTA
From 21-JUL-17 16:53:00 to 21-JUL-17 16:53:00 (CST-6)
Location: DOWNER
Magnitude: 1.00 
Reported by: Storm Chaser

Hail covered the road east of Downer.

Thunderstorm Wind in OTTER TAIL, MINNESOTA
From 22-JUL-17 03:20:00 to 22-JUL-17 03:20:00 (CST-6)
Location: PELICAN RAPIDS
Magnitude: 52.00 EG
Reported by: Public

Large branches were blown down at Lida Greens Golf Course.

Hail in CLAY, MINNESOTA
From 22-JUL-17 02:32:00 to 22-JUL-17 02:32:00 (CST-6)
Location: COMSTOCK
Magnitude: 1.25 
Reported by: Public

A hail patch was noted across highway 75. Some of the hail was still a bit larger than a quarter about 10 minutes after it had passed.

Hail in WILKIN, MINNESOTA
From 22-JUL-17 03:00:00 to 22-JUL-17 03:00:00 (CST-6)
Location: LAWNDALE
Magnitude: 1.00 
Reported by: Public

Some large hail fell along with strong winds and heavy rain.

Hail in OTTER TAIL, MINNESOTA
From 22-JUL-17 03:26:00 to 22-JUL-17 03:26:00 (CST-6)
Location: PELICAN RAPIDS
Magnitude: 1.50 
Reported by: Park/Forest Service

Ping pong ball sized hail or larger fell across northern Maplewood Township. A few large trees were also blown down at Maplewood State Park.