A strong surface low pressure system lifting north through the Dakotas, combined with large scale ascent ahead of a long wave upper level trough, brought a prolonged period of severe weather to parts of west and central North Dakota Thursday, September 9th. Severe Thunderstorm Watch number 650 was issued during the mid afternoon in anticipation of increasing thunderstorm coverage and intensity along a surface warm front and ahead of the upper level trough. Tornado Watch number 651 was issued shortly after, as observations and short range model guidance indicated increasing low level wind shear conducive to tornadogenesis.
Multiple severe thunderstorm and tornado warnings were issued. Numerous reports of large hail and severe thunderstorm winds were received along with reports of flash flooding and a tornado.

Hail in WELLS, NORTH DAKOTA
From 09-SEP-10 13:40:00 to 09-SEP-10 13:45:00 (CST-6)
Location: HARVEY ARPT
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in WELLS, NORTH DAKOTA
From 09-SEP-10 13:45:00 to 09-SEP-10 13:50:00 (CST-6)
Location: HARVEY ARPT
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm Wind in SLOPE, NORTH DAKOTA
From 09-SEP-10 14:25:00 to 09-SEP-10 14:35:00 (MST-7)
Location: MARMARTH
Magnitude: 61.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

The strong thunderstorm winds resulted in roof damage.

Hail in SLOPE, NORTH DAKOTA
From 09-SEP-10 15:00:00 to 09-SEP-10 15:15:00 (MST-7)
Location: MARMARTH
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in GOLDEN VALLEY, NORTH DAKOTA
From 09-SEP-10 15:19:00 to 09-SEP-10 15:29:00 (MST-7)
Location: GOLVA
Magnitude: 2.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Funnel Cloud in BILLINGS, NORTH DAKOTA
From 09-SEP-10 15:45:00 to 09-SEP-10 15:45:00 (MST-7)
Location: FRYBURG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A brief funnel cloud appeared.

Hail in BILLINGS, NORTH DAKOTA
From 09-SEP-10 15:55:00 to 09-SEP-10 16:05:00 (MST-7)
Location: FRYBURG
Magnitude: 2.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Strong thunderstorm winds accompanied the large hail.

Funnel Cloud in SLOPE, NORTH DAKOTA
From 09-SEP-10 14:25:00 to 09-SEP-10 14:25:00 (MST-7)
Location: MARMARTH
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A brief funnel cloud was reported.

Thunderstorm Wind in BILLINGS, NORTH DAKOTA
From 09-SEP-10 15:55:00 to 09-SEP-10 16:05:00 (MST-7)
Location: FRYBURG
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Large hail accompanied the strong thunderstorm winds.

Hail in BILLINGS, NORTH DAKOTA
From 09-SEP-10 15:46:00 to 09-SEP-10 15:52:00 (MST-7)
Location: FRYBURG
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in STARK, NORTH DAKOTA
From 09-SEP-10 16:00:00 to 09-SEP-10 16:08:00 (MST-7)
Location: BELFIELD
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Hail in STARK, NORTH DAKOTA
From 09-SEP-10 16:05:00 to 09-SEP-10 16:11:00 (MST-7)
Location: GLADSTONE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in STARK, NORTH DAKOTA
From 09-SEP-10 16:06:00 to 09-SEP-10 16:12:00 (MST-7)
Location: BELFIELD
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in STARK, NORTH DAKOTA
From 09-SEP-10 16:20:00 to 09-SEP-10 16:25:00 (MST-7)
Location: BELFIELD
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 75.00K
Reported by: Trained Spotter

The large hail resulted in some crop damage.

Hail in STARK, NORTH DAKOTA
From 09-SEP-10 16:23:00 to 09-SEP-10 16:28:00 (MST-7)
Location: TAYLOR
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in STARK, NORTH DAKOTA
From 09-SEP-10 16:31:00 to 09-SEP-10 16:38:00 (MST-7)
Location: BELFIELD
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in DUNN, NORTH DAKOTA
From 09-SEP-10 17:15:00 to 09-SEP-10 17:22:00 (MST-7)
Location: EMERSON
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in DUNN, NORTH DAKOTA
From 09-SEP-10 17:30:00 to 09-SEP-10 17:40:00 (MST-7)
Location: MARSHALL
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MERCER, NORTH DAKOTA
From 09-SEP-10 18:36:00 to 09-SEP-10 18:45:00 (CST-6)
Location: BEULAH
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Hail in GOLDEN VALLEY, NORTH DAKOTA
From 09-SEP-10 18:45:00 to 09-SEP-10 18:53:00 (MST-7)
Location: TROTTERS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MCKENZIE, NORTH DAKOTA
From 09-SEP-10 19:35:00 to 09-SEP-10 19:44:00 (MST-7)
Location: GRASSY BUTTE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Thunderstorm Wind in MERCER, NORTH DAKOTA
From 09-SEP-10 18:55:00 to 09-SEP-10 19:02:00 (CST-6)
Location: BEULAH
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Heavy rain accompanied the strong thunderstorm winds.

Thunderstorm Wind in MERCER, NORTH DAKOTA
From 09-SEP-10 19:36:00 to 09-SEP-10 19:44:00 (CST-6)
Location: ZAP
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Heavy rain accompanied the strong thunderstorm winds.

Thunderstorm Wind in GOLDEN VALLEY, NORTH DAKOTA
From 09-SEP-10 18:50:00 to 09-SEP-10 19:00:00 (MST-7)
Location: SENTINEL BUTTE
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Large hail accompanied the strong thunderstorm winds.

Hail in GOLDEN VALLEY, NORTH DAKOTA
From 09-SEP-10 18:50:00 to 09-SEP-10 19:00:00 (MST-7)
Location: SENTINEL BUTTE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Strong thunderstorm winds accompanied the large hail.

High Wind in WARD, NORTH DAKOTA
From 09-SEP-10 21:32:00 to 09-SEP-10 21:42:00 (CST-6)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Strong winds associated with a nocturnal low level jet briefly mixed down to the surface in Minot.

Tornado in SLOPE, NORTH DAKOTA
From 09-SEP-10 15:00:00 to 09-SEP-10 15:05:00 (MST-7)
Location: MARMARTH
Tornado F-scale: EF0
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Newspaper

A tornado touched down near a farmstead in rural Slope County. One small outbuilding was damaged and several small trees were blown down. The damage was consistent with EF0 tornado damage on the Enhanced Fujita Scale. From that it was determined that wind speeds were near 85 mph with this tornado.

Flash Flood in MERCER, NORTH DAKOTA
From 09-SEP-10 20:00:00 to 09-SEP-10 23:00:00 (CST-6)
Location: GOLDEN VLY
Flood cause: Heavy Rain
Property damage: 45.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Torrential rain resulted in a flash flood around Zap. A thunderstorm rain total of 4.75 inches was reported from six miles northwest of Zap. Two feet of water covered county roads and highway 200. There was also a report of water in the basement of a home. In addition, Spring Creek near Zap rose nearly ten feet in response to the rain. It pushed the creek to almost one foot over flood stage. The creek was quick to receed.