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.

Thunderstorm Wind in CAVALIER, NORTH DAKOTA
From 26-JUL-10 21:45:00 to 26-JUL-10 21:45:00 (CST-6)
Location: EASBY
Magnitude: 70.00 EG
Reported by: Public

A new grain bin was dented to a depth of three to four feet.

Thunderstorm Wind in BARNES, NORTH DAKOTA
From 27-JUL-10 02:45:00 to 27-JUL-10 02:45:00 (CST-6)
Location: DAZEY BRYN ARPT
Magnitude: 60.00 EG
Reported by: Public

Damage occurred along the Barnes and Griggs county line.

Thunderstorm Wind in CASS, NORTH DAKOTA
From 27-JUL-10 00:35:00 to 27-JUL-10 00:35:00 (CST-6)
Location: HORACE
Magnitude: 52.00 EG
Reported by: Amateur Radio

Strong winds were reported at Horace.

Thunderstorm Wind in RAMSEY, NORTH DAKOTA
From 26-JUL-10 20:34:00 to 26-JUL-10 20:36:00 (CST-6)
Location: HAMPDEN
Magnitude: 65.00 MG
Reported by: Mesonet

Peak wind measured at the Hampden RAWS sensor.

Thunderstorm Wind in CAVALIER, NORTH DAKOTA
From 26-JUL-10 20:34:00 to 26-JUL-10 20:36:00 (CST-6)
Location: LOMA
Magnitude: 65.00 MG
Reported by: Mesonet

Peak wind measured by the Hampden RAWS sensor near the Ramsey County line.

Tornado in CAVALIER, NORTH DAKOTA
From 26-JUL-10 20:17:00 to 26-JUL-10 20:27:00 (CST-6)
Location: ALSEN
Tornado F-scale: EF0
Reported by: Public

Tornado tracked intermittently for about 5 miles over mainly open rangeland. Tornado was enshrouded in damaging downburst winds and very heavy rains. Peak winds were estimated to 85 mph.

Thunderstorm Wind in CASS, NORTH DAKOTA
From 27-JUL-10 00:40:00 to 27-JUL-10 00:40:00 (CST-6)
Location: COTTER
Magnitude: 63.00 MG
Reported by: Trained Spotter

The strong winds were measured at the corner of University Avenue and 32nd avenue south in Fargo.

Thunderstorm Wind in CASS, NORTH DAKOTA
From 27-JUL-10 03:40:00 to 27-JUL-10 03:40:00 (CST-6)
Location: BUFFALO
Magnitude: 58.00 MG
Reported by: Mesonet

The wind gust was measured by an ND DOT RWIS sensor near Buffalo.

Thunderstorm Wind in CASS, NORTH DAKOTA
From 27-JUL-10 03:54:00 to 27-JUL-10 03:54:00 (CST-6)
Location: CASSELTON
Magnitude: 56.00 EG
Reported by: Broadcast Media

The wind speeds were estimated.

Thunderstorm Wind in BARNES, NORTH DAKOTA
From 26-JUL-10 23:25:00 to 26-JUL-10 23:35:00 (CST-6)
Location: SIBLEY
Magnitude: 87.00 EG
Crop damage: 1.00M
Reported by: NWS Storm Survey

Widespread downburst wind damage was noted across northeast Barnes County and into adjacent portions of southwest Steele County and southeast Griggs County.  Significant crop and tree damage occurred across Baldwin Township which indicated peak wind speeds of from 90 to 100 mph. This damage is separate from concurrent and adjacent tornado damage.

Hail in TOWNER, NORTH DAKOTA
From 26-JUL-10 19:37:00 to 26-JUL-10 19:37:00 (CST-6)
Location: ROCKLAKE
Magnitude: 1.00 
Reported by: Public

Thunderstorm Wind in CAVALIER, NORTH DAKOTA
From 26-JUL-10 19:55:00 to 26-JUL-10 19:55:00 (CST-6)
Location: MUNICH
Magnitude: 65.00 EG
Reported by: Trained Spotter

Two foot diameter trees were uprooted.

Thunderstorm Wind in CAVALIER, NORTH DAKOTA
From 26-JUL-10 20:45:00 to 26-JUL-10 20:45:00 (CST-6)
Location: NEKOMA
Magnitude: 60.00 EG
Reported by: Trained Spotter

Trees were blown down onto powerlines, resulting in power outages.

Tornado in BENSON, NORTH DAKOTA
From 26-JUL-10 21:10:00 to 26-JUL-10 21:16:00 (CST-6)
Location: HESPER
Tornado F-scale: EF0
Reported by: Public

This tornado tracked intermittently for about 3 miles, mainly over open fields and pasture. Some larger branches were broken off in a shelter belt.  peak winds estimated to 80 mph.

Tornado in BARNES, NORTH DAKOTA
From 26-JUL-10 23:30:00 to 26-JUL-10 23:59:00 (CST-6)
Location: SIBLEY
Tornado F-scale: EF2
Property damage: 1.00M
Crop damage: 250.00K
Reported by: NWS Storm Survey

Several grain bins were lofted for a mile or more and destroyed. Large pine trees were uprooted and numerous trees were stripped of leaves and branches. Equipment storage buildings were unroofed and otherwise flattened to the ground.  The tornado tracked continuously for at 14 to 15 miles. There was also widespread wind and hail damage observed in the area.

Thunderstorm Wind in STEELE, NORTH DAKOTA
From 26-JUL-10 23:25:00 to 26-JUL-10 23:35:00 (CST-6)
Location: LUVERNE
Magnitude: 87.00 EG
Property damage: 0.00K
Crop damage: 500.00K
Reported by: NWS Storm Survey

Widespread downburst wind damage was noted across southwest Steele County and into adjacent portions of southeast Griggs County and northeast Barnes County.  Significant crop and tree damage occurred across the southern half of Willow Lake  Township which indicated peak wind speeds of from 90 to 100 mph.

Tornado in CASS, NORTH DAKOTA
From 27-JUL-10 05:20:00 to 27-JUL-10 05:25:00 (CST-6)
Location: WOODS
Tornado F-scale: EF1
Crop damage: 250.00K
Reported by: NWS Storm Survey

Significant tree damage occurred at three farmsteads with debris thrown in divergent patterns. Peak winds were estimated to 105 mph. Significant crop damage occurred across southern Davenport township due to additional widepsread damaging winds and large hail.

Thunderstorm Wind in GRIGGS, NORTH DAKOTA
From 26-JUL-10 23:20:00 to 26-JUL-10 23:30:00 (CST-6)
Location: KARNAK
Magnitude: 87.00 EG
Crop damage: 1.00M
Reported by: NWS Storm Survey

Widespread downburst wind damage was noted across southeast Griggs County and into adjacent portions of southwest Steele County and northeast Barnes County.  Significant crop and tree damage occurred across the southern half of Broadview Township which indicated peak wind speeds of from 90 to 100 mph.