Warm mid level temperatures held back convection until the mid evening of the 26th, when a line of thunderstorms flared up north of Devils Lake. As these thunderstorms moved east, they began to bow and produce strong straight line winds at the surface. Just before midnight, thunderstorms to the south of the initial line strengthened and also produced sporadic reports of strong winds from south of Cooperstown down through the Fargo/Moorhead area and into portions of west central Minnesota. There was a bit of a lull in the early morning from severe storms, but another strong line fired up again by mid afternoon. However, by this time, most of the strongest storms were over Grant County and areas further south and east. The Highway 10 corridor from Barnesville to Perham to Sebeka was hit by several rounds of thunderstorms and heavy rain, which resulted in flash flooding.

Flash Flood in OTTER TAIL, MINNESOTA
From 27-JUL-10 14:30:00 to 27-JUL-10 19:00:00 (CST-6)
Location: PERHAM
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 10.00K
Reported by: Public

Street flooding was caused by 4.25 inches of rain.

Hail in WADENA, MINNESOTA
From 27-JUL-10 12:05:00 to 27-JUL-10 12:05:00 (CST-6)
Location: BLUE GRASS
Magnitude: 0.75 
Reported by: Public

Flash Flood in WADENA, MINNESOTA
From 27-JUL-10 14:30:00 to 27-JUL-10 14:30:00 (CST-6)
Location: BLUE GRASS
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 10.00K
Reported by: Public

Four to five inches of rain fell, flooding a yard.

Thunderstorm Wind in KITTSON, MINNESOTA
From 26-JUL-10 22:14:00 to 26-JUL-10 22:14:00 (CST-6)
Location: HALLOCK ARPT
Magnitude: 54.00 MG
Reported by: AWOS

The west-northwest wind gust was measured by the Hallock AWOS.

Flash Flood in CLAY, MINNESOTA
From 27-JUL-10 14:30:00 to 27-JUL-10 19:00:00 (CST-6)
Location: BARNESVILLE
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 5.00K
Reported by: Public

Nearly three inches of rain fell, causing flooding in low spots. Local sloughs and creeks also filled with water and overspilled their banks.

Tornado in OTTER TAIL, MINNESOTA
From 27-JUL-10 09:11:00 to 27-JUL-10 09:12:00 (CST-6)
Location: ERHARD
Tornado F-scale: EF0
Reported by: Trained Spotter

Two funnels were observed in the Star Lake area. One produced a brief touchdown but no apparent damage.

Funnel Cloud in GRANT, MINNESOTA
From 27-JUL-10 15:22:00 to 27-JUL-10 15:22:00 (CST-6)
Location: ERDAHL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Hail in WADENA, MINNESOTA
From 27-JUL-10 06:01:00 to 27-JUL-10 06:01:00 (CST-6)
Location: SEBEKA
Magnitude: 0.88 
Reported by: COOP Observer

Hail in OTTER TAIL, MINNESOTA
From 27-JUL-10 09:05:00 to 27-JUL-10 09:05:00 (CST-6)
Location: SPIRIT LAKE
Magnitude: 1.00 
Reported by: Public

Nickel to quarter size hail fell.

Hail in GRANT, MINNESOTA
From 27-JUL-10 15:29:00 to 27-JUL-10 15:29:00 (CST-6)
Location: HOFFMAN
Magnitude: 0.88 
Reported by: Fire Department/Rescue

Thunderstorm Wind in BECKER, MINNESOTA
From 27-JUL-10 04:30:00 to 27-JUL-10 04:30:00 (CST-6)
Location: WHITE EARTH
Magnitude: 60.00 EG
Reported by: Park/Forest Service

Several small to medium sized trees were blown down.

Thunderstorm Wind in OTTER TAIL, MINNESOTA
From 27-JUL-10 02:00:00 to 27-JUL-10 02:00:00 (CST-6)
Location: VERGAS
Magnitude: 52.00 EG
Reported by: Public

Strong winds occurred at Vergas.

Thunderstorm Wind in ROSEAU, MINNESOTA
From 26-JUL-10 22:40:00 to 26-JUL-10 22:40:00 (CST-6)
Location: PELAN
Magnitude: 78.00 EG
Property damage: 200.00K
Crop damage: 1.00M
Reported by: Law Enforcement

Downburst winds raked across portions of western Roseau County.  Numerous trees were knocked down across portions of Polonia and Barto Townships.  Several farmsteads had tree and roofing damage. Some forested areas saw 1 of every 4 trees knocked down.