A prolonged severe weather event materialized July 17th with an extremely unstable atmosphere present and supportive mid level dynamics. The first wave of storms occurred from the mid morning through the early afternoon hours as a short wave mid level impulse crested the central plains upper ridge across North Dakota. Storms intensified ahead of this feature, prompting the issuance of several severe thunderstorm and tornado warnings. Numerous reports of large hail and severe thunderstorm wind gusts were received. In addition, 3 confirmed tornadoes occurred with this first wave.
The second wave occurred from the mid afternoon through the mid evening hours. This mainly consisted of one supercell thunderstorm. Severe weather reports included very large hail, strong winds, and two confirmed tornadoes. This included an EF3 tornado in Lamoure County.

Hail in WELLS, NORTH DAKOTA
From 17-JUL-11 11:28:00 to 17-JUL-11 11:34:00 (CST-6)
Location: HEIMDAL
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MCHENRY, NORTH DAKOTA
From 17-JUL-11 09:38:00 to 17-JUL-11 09:44:00 (CST-6)
Location: VELVA
Magnitude: 2.75 
Property damage: 150.00K
Crop damage: 250.00K
Reported by: Public

The large hail caused damage to area crops. The hail also damaged windows, siding, and vehicles. The damage amount is estimated.

Hail in LA MOURE, NORTH DAKOTA
From 17-JUL-11 17:18:00 to 17-JUL-11 17:24:00 (CST-6)
Location: GRAND RAPIDS
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

There were no reports of damage associated with the large hail.

Thunderstorm Wind in WARD, NORTH DAKOTA
From 17-JUL-11 09:11:00 to 17-JUL-11 09:16:00 (CST-6)
Location: SAWYER
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Hail in WELLS, NORTH DAKOTA
From 17-JUL-11 11:45:00 to 17-JUL-11 11:54:00 (CST-6)
Location: BREMEN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Tornado in WELLS, NORTH DAKOTA
From 17-JUL-11 10:48:00 to 17-JUL-11 10:49:00 (CST-6)
Location: HARVEY ARPT
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

This tornado touched down in the open country. There were no impacts to structures and so no reports of damage.

Hail in MCHENRY, NORTH DAKOTA
From 17-JUL-11 09:40:00 to 17-JUL-11 09:47:00 (CST-6)
Location: VOLTAIRE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in MCHENRY, NORTH DAKOTA
From 17-JUL-11 09:50:00 to 17-JUL-11 09:56:00 (CST-6)
Location: BERGEN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in MCHENRY, NORTH DAKOTA
From 17-JUL-11 09:56:00 to 17-JUL-11 10:10:00 (CST-6)
Location: BALFOUR
Magnitude: 2.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

There were no reports of damage associated with the large hail. Strong winds accompanied the large hail.

Thunderstorm Wind in MCHENRY, NORTH DAKOTA
From 17-JUL-11 09:56:00 to 17-JUL-11 10:01:00 (CST-6)
Location: BALFOUR
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Large hail accompanied the strong winds.

Funnel Cloud in KIDDER, NORTH DAKOTA
From 17-JUL-11 14:50:00 to 17-JUL-11 14:50:00 (CST-6)
Location: CRYSTAL SPGS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in STUTSMAN, NORTH DAKOTA
From 17-JUL-11 15:07:00 to 17-JUL-11 15:14:00 (CST-6)
Location: MEDINA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rotation was observed with this storm.

Hail in STUTSMAN, NORTH DAKOTA
From 17-JUL-11 16:22:00 to 17-JUL-11 16:28:00 (CST-6)
Location: MILLARTON
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

There were no reports of damage associated with the large hail.

Funnel Cloud in DICKEY, NORTH DAKOTA
From 17-JUL-11 17:42:00 to 17-JUL-11 17:42:00 (CST-6)
Location: FULLERTON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Tornado in FOSTER, NORTH DAKOTA
From 17-JUL-11 12:42:00 to 17-JUL-11 12:45:00 (CST-6)
Location: JUANITA
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

This tornado touched down in the open country. There were no impacts to structures and so no reports of damage.

Hail in STUTSMAN, NORTH DAKOTA
From 17-JUL-11 15:22:00 to 17-JUL-11 15:28:00 (CST-6)
Location: MILLARTON
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

There were no reports of damage associated with the large hail.

Thunderstorm Wind in STUTSMAN, NORTH DAKOTA
From 17-JUL-11 15:34:00 to 17-JUL-11 15:41:00 (CST-6)
Location: WINDSOR
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Very heavy rain and pea size hail accompanied the strong thunderstorm winds.

Funnel Cloud in DICKEY, NORTH DAKOTA
From 17-JUL-11 17:45:00 to 17-JUL-11 17:45:00 (CST-6)
Location: OAKES
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Tornado in FOSTER, NORTH DAKOTA
From 17-JUL-11 13:28:00 to 17-JUL-11 13:29:00 (CST-6)
Location: GLENFIELD
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

This tornado touched down in the open country. There were no impacts to structures and so no reports of damage.

Hail in STUTSMAN, NORTH DAKOTA
From 17-JUL-11 16:10:00 to 17-JUL-11 16:15:00 (CST-6)
Location: SYDNEY
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Lightning in LA MOURE, NORTH DAKOTA
From 17-JUL-11 17:29:00 to 17-JUL-11 17:29:00 (CST-6)
Location: LA MOURE
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A lightning strike caused damage to a building in LaMoure.

Tornado in DICKEY, NORTH DAKOTA
From 17-JUL-11 18:06:00 to 17-JUL-11 18:07:00 (CST-6)
Location: FULLERTON
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

This tornado touched down in the open country. There were no impacts to structures and so no reports of damage. This was the same storm complex that produced the EF3 tornado earlier in Lamoure County.

Hail in LA MOURE, NORTH DAKOTA
From 17-JUL-11 17:29:00 to 17-JUL-11 17:34:00 (CST-6)
Location: LA MOURE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in WARD, NORTH DAKOTA
From 17-JUL-11 08:48:00 to 17-JUL-11 08:53:00 (CST-6)
Location: RYDER
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Tornado in LA MOURE, NORTH DAKOTA
From 17-JUL-11 16:57:00 to 17-JUL-11 17:37:00 (CST-6)
Location: NORTONVILLE
Tornado F-scale: EF3
Property damage: 500.00K
Crop damage: 250.00K
Reported by: NWS Storm Survey

A National Weather Service storm survey confirmed that an EF3 tornado touched down around seven miles southeast of Nortonville, then moved southeast before lifting six miles south southeast of Berlin. This was a long tracked tornado across parts of Russell, Wano, Henrietta, and Badger townships. Damage was observed all along the tornado path, with no fewer than five farmsteads impacted, some very severely. One injury occurred where a farm home was damaged beyond repair. There were no deaths. The worst damage consisted of a farm house completely destroyed, outbuildings completely destroyed, a vehicle tossed up to one half mile away from its original location and almost unrecognizable as a motor vehicle, and a significant number of very large hard and soft wood trees both snapped and uprooted. The violent nature of tornadoes was evidenced by the twisted and mangled trees. In one case farm animals were killed. The tornado damage corresponded to EF3 on the Enhanced Fujita Scale. From that it was determined that wind speeds were on the order of 165 miles per hour.

Hail in LA MOURE, NORTH DAKOTA
From 17-JUL-11 17:05:00 to 17-JUL-11 17:35:00 (CST-6)
Location: BERLIN
Magnitude: 2.75 
Property damage: 20.00K
Crop damage: 20.00K
Reported by: Law Enforcement

Hail as large as hockey pucks fell along the path of the supercell thunderstorm and EF3 tornado that moved through LaMoure County. See the EF3 tornado entry for LaMoure County.

Hail in MCHENRY, NORTH DAKOTA
From 17-JUL-11 10:06:00 to 17-JUL-11 10:11:00 (CST-6)
Location: BALFOUR
Magnitude: 2.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

There were no reports of damage associated with the large hail.

Hail in WELLS, NORTH DAKOTA
From 17-JUL-11 11:18:00 to 17-JUL-11 11:24:00 (CST-6)
Location: HEIMDAL
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in WELLS, NORTH DAKOTA
From 17-JUL-11 11:22:00 to 17-JUL-11 11:28:00 (CST-6)
Location: HEIMDAL
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in WARD, NORTH DAKOTA
From 17-JUL-11 09:10:00 to 17-JUL-11 09:18:00 (CST-6)
Location: SURREY
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

There were no reports of damage associated with the large hail.

Hail in WARD, NORTH DAKOTA
From 17-JUL-11 09:25:00 to 17-JUL-11 09:35:00 (CST-6)
Location: SAWYER
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

There were no reports of damage associated with the large hail.

Thunderstorm Wind in DICKEY, NORTH DAKOTA
From 17-JUL-11 18:18:00 to 17-JUL-11 18:24:00 (CST-6)
Location: MERRICOURT
Magnitude: 61.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Evergreen trees were snapped in the city of Merricourt.