An impressive set up for severe weather occurred on the evening of the 30th. A surface low set up near Fargo with a warm front extending out to its east. Meanwhile, a cold front extended to the south, down into central Nebraska. In the warm sector, temperatures climbed into the low to mid 80s with dew points in the middle 60s. As convection blossomed in the evening, thunderstorms erupted all along the cold front, from North Dakota all the way down into Nebraska.

Thunderstorm Wind in RICHLAND, NORTH DAKOTA
From 30-MAY-11 19:00:00 to 30-MAY-11 19:00:00 (CST-6)
Location: LIDGERWOOD
Magnitude: 52.00 EG
Reported by: Public

The tops of trees were taken off.

Thunderstorm Wind in SARGENT, NORTH DAKOTA
From 30-MAY-11 19:10:00 to 30-MAY-11 19:10:00 (CST-6)
Location: GWINNER ARPT
Magnitude: 52.00 EG
Reported by: Trained Spotter

An 18 inch diameter tree was knocked down.

Thunderstorm Wind in SARGENT, NORTH DAKOTA
From 30-MAY-11 19:15:00 to 30-MAY-11 19:15:00 (CST-6)
Location: GWINNER ARPT
Magnitude: 54.00 EG
Reported by: Trained Spotter

The wind gust occurred three miles east of Gwinner.

Thunderstorm Wind in SARGENT, NORTH DAKOTA
From 30-MAY-11 19:15:00 to 30-MAY-11 19:15:00 (CST-6)
Location: GWINNER ARPT
Magnitude: 59.00 MG
Reported by: AWOS

Thunderstorm Wind in SARGENT, NORTH DAKOTA
From 30-MAY-11 19:23:00 to 30-MAY-11 19:23:00 (CST-6)
Location: GWINNER ARPT
Magnitude: 54.00 EG
Reported by: Fire Department/Rescue

The strong wind snapped a 12 inch diameter tree in Gwinner.

Thunderstorm Wind in RANSOM, NORTH DAKOTA
From 30-MAY-11 19:28:00 to 30-MAY-11 19:28:00 (CST-6)
Location: MC LEOD
Magnitude: 56.00 EG
Reported by: Public

A wind gust estimated at 65 mph occurred at McLeod.

Funnel Cloud in CASS, NORTH DAKOTA
From 30-MAY-11 19:45:00 to 30-MAY-11 19:45:00 (CST-6)
Location: WOODS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The funnel cloud was spotted 7 miles west of Kindred.

Thunderstorm Wind in CASS, NORTH DAKOTA
From 30-MAY-11 20:04:00 to 30-MAY-11 20:04:00 (CST-6)
Location: FARGO
Magnitude: 50.00 MG
Reported by: Mesonet

The wind gust was measured at the NDAWN mesonet site at North Dakota State University.

Thunderstorm Wind in CASS, NORTH DAKOTA
From 30-MAY-11 20:00:00 to 30-MAY-11 20:00:00 (CST-6)
Location: FARGO
Magnitude: 56.00 EG
Reported by: Public

Tree and fence damage occurred all over Fargo.

Thunderstorm Wind in CASS, NORTH DAKOTA
From 30-MAY-11 20:05:00 to 30-MAY-11 20:05:00 (CST-6)
Location: RIVERSIDE
Magnitude: 56.00 EG
Reported by: Trained Spotter

Large trees and fences were blown down all over West Fargo. Power outages were also reported.

Thunderstorm Wind in CASS, NORTH DAKOTA
From 30-MAY-11 20:06:00 to 30-MAY-11 20:06:00 (CST-6)
Location: FARGO
Magnitude: 63.00 MG
Reported by: ASOS

The wind gust was measured at Hector Airport on the north end of Fargo.

Funnel Cloud in GRAND FORKS, NORTH DAKOTA
From 30-MAY-11 20:30:00 to 30-MAY-11 20:30:00 (CST-6)
Location: MERRIFIELD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Rotation was seen six miles south of Grand Forks.

Funnel Cloud in CASS, NORTH DAKOTA
From 30-MAY-11 20:13:00 to 30-MAY-11 20:13:00 (CST-6)
Location: HARWOOD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A funnel cloud was spotted two miles east of Harwood.

Thunderstorm Wind in CASS, NORTH DAKOTA
From 30-MAY-11 20:15:00 to 30-MAY-11 20:15:00 (CST-6)
Location: ARGUSVILLE
Magnitude: 56.00 EG
Reported by: Trained Spotter

A 60 foot tall tree was blown over.

Hail in GRAND FORKS, NORTH DAKOTA
From 30-MAY-11 20:32:00 to 30-MAY-11 20:32:00 (CST-6)
Location: GRAND FORKS
Magnitude: 0.75 
Reported by: Public

Penny sized hail fell in south Grand Forks.

Thunderstorm Wind in TRAILL, NORTH DAKOTA
From 30-MAY-11 21:02:00 to 30-MAY-11 21:02:00 (CST-6)
Location: BUXTON
Magnitude: 57.00 MG
Reported by: Mesonet

The Buxton DOT RWIS reported a wind gust of 66 mph.

Thunderstorm Wind in CASS, NORTH DAKOTA
From 30-MAY-11 20:15:00 to 30-MAY-11 20:15:00 (CST-6)
Location: HARWOOD
Magnitude: 60.00 EG
Reported by: NWS Employee

A semi truck was flipped along Interstate 29 at Harwood.

Hail in GRAND FORKS, NORTH DAKOTA
From 30-MAY-11 20:36:00 to 30-MAY-11 20:36:00 (CST-6)
Location: POWELL
Magnitude: 1.00 
Reported by: NWS Employee

Nickel to quarter sized hail fell just west of the National Weather Service office.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 30-MAY-11 20:45:00 to 30-MAY-11 20:45:00 (CST-6)
Location: BOLACK
Magnitude: 52.00 EG
Reported by: NWS Storm Survey

A few trees were knocked down in a shelterbelt along Interstate 29 near mile point 147.

Tornado in CASS, NORTH DAKOTA
From 30-MAY-11 20:03:00 to 30-MAY-11 20:13:00 (CST-6)
Location: WEST FARGO
Tornado F-scale: EF2
Property damage: 750.00K
Reported by: NWS Storm Survey

This tornado tracked northward and brushed the west edge of the industrial park of northwest Fargo and the east edge of Reiles Acres before lifting east of Harwood. The tornado was likely enshrouded in downburst winds and heavy rains for part of this track. Two guyed radio towers collapsed, several empty semi-trailers and travel trailers were flipped and thrown, steel wall and roofing panels were torn from industrial buildings, and numerous power poles and trees were snapped. peak winds were estimated at 135 mph.

Tornado in CASS, NORTH DAKOTA
From 30-MAY-11 19:55:00 to 30-MAY-11 19:59:00 (CST-6)
Location: HORACE
Tornado F-scale: EF2
Property damage: 600.00K
Reported by: NWS Storm Survey

This tornado tracked northward for about four miles and lifted near the Woodhaven Park in southwest Fargo. The tornado was likely enshrouded in downburst winds and heavy rain as it knocked down several wooden power poles and two metal truss power towers along its path. Sections of roofing were torn off of two apartment buildings. Many residences had tree, vehicle and roof damage. Peak wind were estimated at 135 mph.

Tornado in CASS, NORTH DAKOTA
From 30-MAY-11 19:52:00 to 30-MAY-11 19:54:00 (CST-6)
Location: ST BENEDICT
Tornado F-scale: EF1
Property damage: 250.00K
Reported by: NWS Storm Survey

This tornado tracked for about two miles to the north-northeast and was likely enshrouded in downburst winds and heavy rains. The tornado flipped a parked semi trailer and tore out two large 40,000 bushel steel grain bins at one farmstead and spread debris downwind for a mile. Several trees were toppled onto rooftops in the community of St. Benedict. Peak winds were estimated at 100 mph.

Thunderstorm Wind in RICHLAND, NORTH DAKOTA
From 30-MAY-11 19:45:00 to 30-MAY-11 19:45:00 (CST-6)
Location: WALCOTT
Magnitude: 54.00 EG
Property damage: 250.00K
Reported by: Public

There were reports of damage to many cars and buildings in Walcott.  The firehall and city administration building lost sections of roofing and falling tree limbs crushed vehicles and roofs of several homes.

Tornado in CASS, NORTH DAKOTA
From 30-MAY-11 19:48:00 to 30-MAY-11 19:50:00 (CST-6)
Location: KINDRED
Tornado F-scale: EF2
Property damage: 50.00K
Reported by: NWS Storm Survey

This tornado originated in Richland County about four miles north of Walcott at 846 pm CDT. The tornado was likely enshrouded in downburst winds and heavy rains. The tornado crossed North Dakota highway 46 and continued to break down several single and double pole wooden power towers in southwest Pleasant township. Peak winds were estimated at 120 mph.

Tornado in RICHLAND, NORTH DAKOTA
From 30-MAY-11 19:46:00 to 30-MAY-11 19:48:00 (CST-6)
Location: WALCOTT
Tornado F-scale: EF2
Property damage: 500.00K
Reported by: NWS Storm Survey

This tornado tracked north northeastward for roughly two miles before crossing into Cass County. The tornado was likely enshrouded in downburst winds and heavy rain. The tornado and accompanying winds knocked down numerous wooden power poles along its path and four steel t-bar high voltage towers. Peak winds were estimated at 120 mph.

Hail in RICHLAND, NORTH DAKOTA
From 30-MAY-11 19:31:00 to 30-MAY-11 19:31:00 (CST-6)
Location: COLFAX
Magnitude: 1.00 
Reported by: Trained Spotter

Thunderstorm Wind in TRAILL, NORTH DAKOTA
From 30-MAY-11 20:29:00 to 30-MAY-11 20:29:00 (CST-6)
Location: KELSO
Magnitude: 54.00 MG
Reported by: Mesonet

The wind gust was measured by the Hillsboro NDAWN mesonet sensor.