On August 12th a mid level ridge and hot surface temperatures sat over the Rocky Mountains and high plains, with Minnesota lying on the eastern periphery. By mid afternoon, temperatures had risen into the mid to upper 90s across western and central North Dakota, and into the lower 90s along the Red River Valley. To the east in Minnesota, temperatures peaked in the 80s. Afternoon dew point values rose into the mid 60s to around 70. Thunderstorms formed during the mid afternoon over the northern Red River Valley and tracked southeast through Wadena County through the early evening. Then, a second round of storms fired up over Kittson County shortly after the first round exited Wadena County. This second round of storms tracked nearly identically to first round, or from Kittson County southeast through Wadena County. These storms produced very large hail and strong wind gusts.

Hail in ROSEAU, MINNESOTA
From 12-AUG-15 14:21:00 to 12-AUG-15 14:21:00 (CST-6)
Location: STRATHCONA
Magnitude: 0.75 
Reported by: Trained Spotter

Hail in ROSEAU, MINNESOTA
From 12-AUG-15 16:28:00 to 12-AUG-15 16:28:00 (CST-6)
Location: FOX
Magnitude: 4.25 
Reported by: Social Media

Numerous very large hailstones were collected and photographed, measuring from 4 to 4.5 inches in diameter.

Hail in ROSEAU, MINNESOTA
From 12-AUG-15 16:30:00 to 12-AUG-15 16:30:00 (CST-6)
Location: FOX
Magnitude: 4.00 
Reported by: Public

Hail in CLEARWATER, MINNESOTA
From 12-AUG-15 16:32:00 to 12-AUG-15 16:32:00 (CST-6)
Location: CLEARBROOK
Magnitude: 1.00 
Reported by: Trained Spotter

Thunderstorm Wind in PENNINGTON, MINNESOTA
From 12-AUG-15 20:33:00 to 12-AUG-15 20:33:00 (CST-6)
Location: THIEF RIVER FALLS
Magnitude: 70.00 EG
Reported by: Emergency Manager

A few trees were uprooted and numerous large branches were blown down around town. One small radio tower was bent over in the middle and a wooden billboard was blown down.

Thunderstorm Wind in PENNINGTON, MINNESOTA
From 12-AUG-15 20:35:00 to 12-AUG-15 20:35:00 (CST-6)
Location: THIEF RIVER FALLS
Magnitude: 70.00 EG
Reported by: NWS Storm Survey

Numerous large tree branches were blown down. Metal and plastic business signage was blown about.

Thunderstorm Wind in PENNINGTON, MINNESOTA
From 12-AUG-15 20:45:00 to 12-AUG-15 20:45:00 (CST-6)
Location: HAZEL
Magnitude: 56.00 EG
Reported by: NWS Storm Survey

Occasional large tree branches and limbs were broken down in shelterbelts and groves across western Smiley and Wyandote townships.

Hail in RED LAKE, MINNESOTA
From 12-AUG-15 21:00:00 to 12-AUG-15 21:00:00 (CST-6)
Location: PLUMMER
Magnitude: 1.25 
Reported by: Social Media

Hail in ROSEAU, MINNESOTA
From 12-AUG-15 16:45:00 to 12-AUG-15 16:45:00 (CST-6)
Location: ROSEAU
Magnitude: 1.75 
Reported by: Trained Spotter

The hail was a mix of quarter to golf ball sized stones.

Thunderstorm Wind in CLEARWATER, MINNESOTA
From 12-AUG-15 16:50:00 to 12-AUG-15 16:50:00 (CST-6)
Location: SHEVLIN
Magnitude: 65.00 EG
Reported by: Emergency Manager

Numerous pine trees were broken down around the area.

Thunderstorm Wind in CLEARWATER, MINNESOTA
From 12-AUG-15 16:52:00 to 12-AUG-15 16:52:00 (CST-6)
Location: SHEVLIN
Magnitude: 61.00 EG
Reported by: Public

Trees were blown down by the strong winds.

Hail in RED LAKE, MINNESOTA
From 12-AUG-15 21:08:00 to 12-AUG-15 21:08:00 (CST-6)
Location: OKLEE
Magnitude: 1.00 
Reported by: Social Media

Hail in CLEARWATER, MINNESOTA
From 12-AUG-15 21:09:00 to 12-AUG-15 21:09:00 (CST-6)
Location: WERNE
Magnitude: 0.88 
Reported by: Social Media

Hail in CLEARWATER, MINNESOTA
From 12-AUG-15 21:30:00 to 12-AUG-15 21:30:00 (CST-6)
Location: BAGLEY
Magnitude: 1.00 
Reported by: Social Media

Hail in ROSEAU, MINNESOTA
From 12-AUG-15 16:55:00 to 12-AUG-15 16:55:00 (CST-6)
Location: MALUNG
Magnitude: 1.00 
Reported by: Trained Spotter

Thunderstorm Wind in HUBBARD, MINNESOTA
From 12-AUG-15 17:20:00 to 12-AUG-15 17:20:00 (CST-6)
Location: LAKE GEORGE
Magnitude: 61.00 EG
Reported by: Public

A sixteen inch diameter pine tree was snapped by the strong wind. Some half inch diameter hail also fell.

Hail in HUBBARD, MINNESOTA
From 12-AUG-15 17:36:00 to 12-AUG-15 17:36:00 (CST-6)
Location: DORSET
Magnitude: 1.00 
Reported by: Public

Hail in HUBBARD, MINNESOTA
From 12-AUG-15 17:50:00 to 12-AUG-15 17:50:00 (CST-6)
Location: NEVIS
Magnitude: 1.25 
Reported by: Trained Spotter

Hail in POLK, MINNESOTA
From 12-AUG-15 21:39:00 to 12-AUG-15 21:39:00 (CST-6)
Location: MC INTOSH
Magnitude: 2.00 
Reported by: Social Media

Hail in POLK, MINNESOTA
From 12-AUG-15 21:55:00 to 12-AUG-15 21:55:00 (CST-6)
Location: FOSSTON MUNI ARPT
Magnitude: 1.00 
Reported by: Public

Dime to quarter sized hail covered the ground.

Hail in MAHNOMEN, MINNESOTA
From 12-AUG-15 22:00:00 to 12-AUG-15 22:00:00 (CST-6)
Location: BEJOU
Magnitude: 1.75 
Reported by: Social Media

Hail in HUBBARD, MINNESOTA
From 12-AUG-15 17:54:00 to 12-AUG-15 17:54:00 (CST-6)
Location: NEVIS
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in CLEARWATER, MINNESOTA
From 12-AUG-15 22:10:00 to 12-AUG-15 22:20:00 (CST-6)
Location: LAKE ITASCA
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in MAHNOMEN, MINNESOTA
From 12-AUG-15 22:32:00 to 12-AUG-15 22:34:00 (CST-6)
Location: NAYTAHWAUSH
Magnitude: 1.75 
Reported by: Trained Spotter

Quarter to golf ball sized hail fell.

Hail in MAHNOMEN, MINNESOTA
From 12-AUG-15 22:40:00 to 12-AUG-15 22:40:00 (CST-6)
Location: NAYTAHWAUSH
Magnitude: 2.00 
Reported by: Public

Hail in KITTSON, MINNESOTA
From 12-AUG-15 13:58:00 to 12-AUG-15 13:58:00 (CST-6)
Location: HALMA
Magnitude: 0.88 
Reported by: Public

The hail fell near the intersection of county road 7 and Minnesota 11.

Hail in MARSHALL, MINNESOTA
From 12-AUG-15 14:49:00 to 12-AUG-15 14:49:00 (CST-6)
Location: THIEF LAKE
Magnitude: 1.00 
Reported by: Public

Hail in ROSEAU, MINNESOTA
From 12-AUG-15 14:33:00 to 12-AUG-15 14:33:00 (CST-6)
Location: STRATHCONA
Magnitude: 0.88 
Reported by: Trained Spotter

Hail in BECKER, MINNESOTA
From 12-AUG-15 23:01:00 to 12-AUG-15 23:03:00 (CST-6)
Location: OSAGE
Magnitude: 1.25 
Reported by: Trained Spotter

Hail in BECKER, MINNESOTA
From 12-AUG-15 23:20:00 to 12-AUG-15 23:20:00 (CST-6)
Location: EVERGREEN
Magnitude: 1.00 
Reported by: Trained Spotter

The power was also knocked out.

Hail in OTTER TAIL, MINNESOTA
From 13-AUG-15 00:00:00 to 13-AUG-15 00:00:00 (CST-6)
Location: BLUFFTON
Magnitude: 1.00 
Reported by: Public

Thunderstorm Wind in HUBBARD, MINNESOTA
From 12-AUG-15 18:01:00 to 12-AUG-15 18:01:00 (CST-6)
Location: OKELEY
Magnitude: 61.00 EG
Reported by: Trained Spotter

Numerous trees were snapped around town.

Hail in KITTSON, MINNESOTA
From 12-AUG-15 18:35:00 to 12-AUG-15 18:35:00 (CST-6)
Location: LAKE BRONSON ARPT
Magnitude: 0.88 
Reported by: Trained Spotter

The hail and one half of an inch of rain fell very quickly.

Funnel Cloud in KITTSON, MINNESOTA
From 12-AUG-15 18:45:00 to 12-AUG-15 18:45:00 (CST-6)
Location: HALMA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A persistent wall cloud with one or two brief funnels was reported.

Thunderstorm Wind in PENNINGTON, MINNESOTA
From 12-AUG-15 16:00:00 to 12-AUG-15 16:00:00 (CST-6)
Location: ERIE
Magnitude: 60.00 EG
Reported by: Public

A resident reported a roof anchored antenna was ripped off and a well anchored eight foot tall wind mill was blown over. The power was also out from 430 pm to 830 pm.

Hail in ROSEAU, MINNESOTA
From 12-AUG-15 16:00:00 to 12-AUG-15 16:00:00 (CST-6)
Location: DUXBY
Magnitude: 1.75 
Reported by: Trained Spotter

Thunderstorm Wind in PENNINGTON, MINNESOTA
From 12-AUG-15 16:05:00 to 12-AUG-15 16:05:00 (CST-6)
Location: ERIE
Magnitude: 70.00 EG
Reported by: Emergency Manager

Numerous large tree branches and limbs were broken down around Star and Hickory townships. At least two wooden power poles were snapped, resulting in widespread power outages.

Hail in ROSEAU, MINNESOTA
From 12-AUG-15 19:00:00 to 12-AUG-15 19:00:00 (CST-6)
Location: GREENBUSH ARPT
Magnitude: 1.00 
Reported by: Trained Spotter

Thunderstorm Wind in PENNINGTON, MINNESOTA
From 12-AUG-15 16:07:00 to 12-AUG-15 16:07:00 (CST-6)
Location: HIGH LNDG
Magnitude: 74.00 EG
Reported by: Emergency Manager

Several grain bins sustained significant damage and large round hay bales were blown across a field. Several large tree branches and limbs were broken down in shelterbelts across Deer Park and Hickory townships.

Thunderstorm Wind in RED LAKE, MINNESOTA
From 12-AUG-15 16:10:00 to 12-AUG-15 16:10:00 (CST-6)
Location: OKLEE
Magnitude: 56.00 EG
Reported by: Emergency Manager

Numerous large tree branches and limbs were broken down across portions of Roland Township, resulting in widespread power outages.

Hail in ROSEAU, MINNESOTA
From 12-AUG-15 19:10:00 to 12-AUG-15 19:10:00 (CST-6)
Location: LONGWORTH
Magnitude: 1.50 
Reported by: Social Media

Hail in MARSHALL, MINNESOTA
From 12-AUG-15 19:28:00 to 12-AUG-15 19:28:00 (CST-6)
Location: MIDDLE RIVER
Magnitude: 1.00 
Reported by: Social Media

Hail in ROSEAU, MINNESOTA
From 12-AUG-15 16:15:00 to 12-AUG-15 16:15:00 (CST-6)
Location: DUXBY
Magnitude: 2.75 
Reported by: Public

Thunderstorm Wind in POLK, MINNESOTA
From 12-AUG-15 16:15:00 to 12-AUG-15 16:15:00 (CST-6)
Location: GULLY
Magnitude: 56.00 EG
Reported by: Emergency Manager

Numerous large tree branches and limbs were broken down across far northeast Polk County, resulting in widespread power outages.

Hail in ROSEAU, MINNESOTA
From 12-AUG-15 16:24:00 to 12-AUG-15 16:24:00 (CST-6)
Location: FOX
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in ROSEAU, MINNESOTA
From 12-AUG-15 16:26:00 to 12-AUG-15 16:26:00 (CST-6)
Location: FOX
Magnitude: 2.75 
Reported by: Trained Spotter

Thunderstorm Wind in MARSHALL, MINNESOTA
From 12-AUG-15 20:00:00 to 12-AUG-15 20:00:00 (CST-6)
Location: NEWFOLDEN
Magnitude: 52.00 EG
Reported by: Social Media

Large branches were blown down around town.

Funnel Cloud in MARSHALL, MINNESOTA
From 12-AUG-15 20:03:00 to 12-AUG-15 20:03:00 (CST-6)
Location: HOLT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

The funnel cloud was short-lived.

Hail in MARSHALL, MINNESOTA
From 12-AUG-15 20:10:00 to 12-AUG-15 20:10:00 (CST-6)
Location: HOLT
Magnitude: 1.00 
Reported by: Public

The hail was accompanied by very strong winds.

Thunderstorm Wind in MARSHALL, MINNESOTA
From 12-AUG-15 20:20:00 to 12-AUG-15 20:20:00 (CST-6)
Location: ROSEWOOD
Magnitude: 61.00 EG
Reported by: Emergency Manager

Trees were blown down near the Pennington County line.

Hail in PENNINGTON, MINNESOTA
From 12-AUG-15 20:30:00 to 12-AUG-15 20:30:00 (CST-6)
Location: THIEF RIVER FALLS
Magnitude: 1.00 
Reported by: Social Media

Thunderstorm Wind in HUBBARD, MINNESOTA
From 12-AUG-15 17:40:00 to 12-AUG-15 17:40:00 (CST-6)
Location: DORSET
Magnitude: 56.00 EG
Reported by: Trained Spotter

A poplar tree was blown down and vehicles were dented by hail between Emmaville and Nevis.