By late in the afternoon of the 31st, a strong thunderstorm formed near Blackduck, Minnesota, and produced very strong winds. Meanwhile, a weak area of surface low pressure over northeast North Dakota combined with a cold front to produce a weak tornado near Crystal. As the cold front pushed into far southeast North Dakota and west central Minnesota, additional strong thunderstorms fired up, producing more hail and strong wind gusts. As evening approached, an upper level disturbance dropped southeast out of Manitoba, Canada, and helped sustain a few more strong thunderstorms from Pembina toward the Lake of the Woods.

Thunderstorm Wind in OTTER TAIL, MINNESOTA
From 31-AUG-13 15:30:00 to 31-AUG-13 15:30:00 (CST-6)
Location: FERGUS FALLS
Magnitude: 54.00 MG
Reported by: Mesonet

The strong winds were measured at the Prairie Wetland Center.

Thunderstorm Wind in OTTER TAIL, MINNESOTA
From 31-AUG-13 15:40:00 to 31-AUG-13 15:40:00 (CST-6)
Location: UNDERWOOD
Magnitude: 65.00 EG
Reported by: Storm Chaser

Trees were blown down and twisted off. Several small sheds or fish houses were blown over and at least one heavily damaged between Wall Lake and Bass Lake.

Hail in GRANT, MINNESOTA
From 31-AUG-13 15:34:00 to 31-AUG-13 15:34:00 (CST-6)
Location: WENDELL
Magnitude: 1.25 
Reported by: Broadcast Media

Thunderstorm Wind in OTTER TAIL, MINNESOTA
From 31-AUG-13 16:05:00 to 31-AUG-13 16:05:00 (CST-6)
Location: URBANK
Magnitude: 60.00 EG
Reported by: Public

A few trees were blown down.

Thunderstorm Wind in KITTSON, MINNESOTA
From 31-AUG-13 16:41:00 to 31-AUG-13 16:41:00 (CST-6)
Location: NOYES
Magnitude: 52.00 MG
Reported by: Mesonet

The winds were measured by a MNDOT RWIS site located along highway 171.

Thunderstorm Wind in BELTRAMI, MINNESOTA
From 31-AUG-13 14:40:00 to 31-AUG-13 14:40:00 (CST-6)
Location: FUNKLEY
Magnitude: 55.00 EG
Reported by: Public

A few trees were blown down with pea size hail.

Thunderstorm Wind in WILKIN, MINNESOTA
From 31-AUG-13 15:05:00 to 31-AUG-13 15:05:00 (CST-6)
Location: ROTHSAY
Magnitude: 77.00 MG
Reported by: Mesonet

The winds were measured by a MNDOT RWIS sensor along Interstate 94.

Hail in BECKER, MINNESOTA
From 31-AUG-13 15:15:00 to 31-AUG-13 15:15:00 (CST-6)
Location: TWO INLETS
Magnitude: 1.00 
Reported by: Trained Spotter

The hail fell along the south side of Hungry Man Lake.

Hail in GRANT, MINNESOTA
From 31-AUG-13 15:27:00 to 31-AUG-13 15:27:00 (CST-6)
Location: HERMAN
Magnitude: 1.00 
Reported by: Trained Spotter

Forty to fifty mile an hour winds accompanied the hail.

Thunderstorm Wind in OTTER TAIL, MINNESOTA
From 31-AUG-13 15:18:00 to 31-AUG-13 15:18:00 (CST-6)
Location: (FFM)FERGUS FALLS AR
Magnitude: 64.00 MG
Reported by: AWOS

The winds were measured by the Fergus Falls airport AWOS.

Thunderstorm Wind in OTTER TAIL, MINNESOTA
From 31-AUG-13 15:28:00 to 31-AUG-13 15:28:00 (CST-6)
Location: (FFM)FERGUS FALLS AR
Magnitude: 50.00 EG
Reported by: Trained Spotter

Several three to four inch diameter tree branches were blown down.

Hail in KITTSON, MINNESOTA
From 31-AUG-13 17:35:00 to 31-AUG-13 17:35:00 (CST-6)
Location: HALMA
Magnitude: 0.88 
Reported by: Trained Spotter

Hail in BELTRAMI, MINNESOTA
From 31-AUG-13 18:56:00 to 31-AUG-13 19:01:00 (CST-6)
Location: MALCOLM
Magnitude: 0.75 
Reported by: Trained Spotter

Thunderstorm Wind in BELTRAMI, MINNESOTA
From 31-AUG-13 14:24:00 to 31-AUG-13 14:24:00 (CST-6)
Location: BLACKDUCK
Magnitude: 52.00 EG
Reported by: Trained Spotter

Very strong winds and pea sized hail were reported on the north shore of Blackduck Lake.

Thunderstorm Wind in BELTRAMI, MINNESOTA
From 31-AUG-13 14:30:00 to 31-AUG-13 14:30:00 (CST-6)
Location: BLACKDUCK
Magnitude: 65.00 EG
Reported by: Emergency Manager

Shingles were blown off of multiple structures and a steeple was blown off a church.

Thunderstorm Wind in KITTSON, MINNESOTA
From 31-AUG-13 17:35:00 to 31-AUG-13 17:35:00 (CST-6)
Location: HALMA
Magnitude: 50.00 EG
Reported by: Trained Spotter

Several four to six inch diameter tree limbs were snapped.

Thunderstorm Wind in KITTSON, MINNESOTA
From 31-AUG-13 17:15:00 to 31-AUG-13 17:15:00 (CST-6)
Location: DONALDSON
Magnitude: 54.00 MG
Reported by: Mesonet

The winds were measured by a MNDOT RWIS site along highway 11.

Thunderstorm Wind in ROSEAU, MINNESOTA
From 31-AUG-13 18:30:00 to 31-AUG-13 18:30:00 (CST-6)
Location: LONGWORTH
Magnitude: 55.00 EG
Reported by: Trained Spotter

A tree was blown down at a campground along the Canadian border.

Hail in BECKER, MINNESOTA
From 31-AUG-13 18:53:00 to 31-AUG-13 18:53:00 (CST-6)
Location: TAMARAC REFUGE
Magnitude: 1.00 
Reported by: Public

The hail fell at the Tamarac Resort on Round Lake.

Thunderstorm Wind in LAKE OF THE WOODS, MINNESOTA
From 31-AUG-13 19:00:00 to 31-AUG-13 19:00:00 (CST-6)
Location: LUDE
Magnitude: 55.00 EG
Reported by: Public

Trees were blown down at Arnesens Rocky Point Resort.

Thunderstorm Wind in BELTRAMI, MINNESOTA
From 31-AUG-13 18:56:00 to 31-AUG-13 19:01:00 (CST-6)
Location: MALCOLM
Magnitude: 50.00 EG
Reported by: Trained Spotter

Several three to five inch diameter branches were snapped.

Hail in LAKE OF THE WOODS, MINNESOTA
From 31-AUG-13 19:05:00 to 31-AUG-13 19:05:00 (CST-6)
Location: HACKETT
Magnitude: 0.88 
Reported by: Trained Spotter