A severe weather outbreak unfolded during the late afternoon and evening of the 15th as thunderstorms developed and intensified along several boundaries over southwest and south central North Dakota. Supercell storms formed initially over the west central and southwest, then formed into an organized bowing segment as the storms progressed eastward into the south central. Severe Thunderstorm Watch number 782 was in effect for this event. Numerous warnings were issued.

Heavy Rain in BURLEIGH, NORTH DAKOTA
From 15-AUG-11 19:45:00 to 15-AUG-11 20:45:00 (CST-6)
Location: BISMARCK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Heavy rain measuring 2.9 inches fell in one hour.

Hail in DUNN, NORTH DAKOTA
From 15-AUG-11 15:05:00 to 15-AUG-11 15:15:00 (MST-7)
Location: EMERSON
Magnitude: 1.75 
Property damage: 35.00K
Crop damage: 75.00K
Reported by: Public

The large hail resulted in broken windows and damage to a vehicle.

Thunderstorm Wind in STARK, NORTH DAKOTA
From 15-AUG-11 15:45:00 to 15-AUG-11 15:52:00 (MST-7)
Location: TAYLOR
Magnitude: 59.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Strong winds were reported.

Hail in SLOPE, NORTH DAKOTA
From 15-AUG-11 15:55:00 to 15-AUG-11 16:15:00 (MST-7)
Location: AMIDON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in STARK, NORTH DAKOTA
From 15-AUG-11 15:57:00 to 15-AUG-11 16:10:00 (MST-7)
Location: RICHARDTON
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Thunderstorm Wind in ADAMS, NORTH DAKOTA
From 15-AUG-11 16:25:00 to 15-AUG-11 16:33:00 (MST-7)
Location: REEDER
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Strong winds were reported.

Thunderstorm Wind in HETTINGER, NORTH DAKOTA
From 15-AUG-11 17:05:00 to 15-AUG-11 17:10:00 (MST-7)
Location: REGENT
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Pea size hail accompanied the strong winds.

Hail in BOWMAN, NORTH DAKOTA
From 15-AUG-11 17:52:00 to 15-AUG-11 17:58:00 (MST-7)
Location: BUFFALO SPGS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MORTON, NORTH DAKOTA
From 15-AUG-11 18:00:00 to 15-AUG-11 18:08:00 (CST-6)
Location: GLEN ULLIN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in BOWMAN, NORTH DAKOTA
From 15-AUG-11 18:15:00 to 15-AUG-11 18:21:00 (MST-7)
Location: SCRANTON
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in GRANT, NORTH DAKOTA
From 15-AUG-11 18:25:00 to 15-AUG-11 18:31:00 (MST-7)
Location: NEW LEIPZIG
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in GRANT, NORTH DAKOTA
From 15-AUG-11 19:05:00 to 15-AUG-11 19:10:00 (MST-7)
Location: LEITH
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in MORTON, NORTH DAKOTA
From 15-AUG-11 19:44:00 to 15-AUG-11 19:49:00 (CST-6)
Location: MANDAN MUNI ARPT
Magnitude: 76.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in BURLEIGH, NORTH DAKOTA
From 15-AUG-11 19:53:00 to 15-AUG-11 19:58:00 (CST-6)
Location: BISMARCK
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Hail in BURLEIGH, NORTH DAKOTA
From 15-AUG-11 20:10:00 to 15-AUG-11 20:16:00 (CST-6)
Location: BISMARCK
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Thunderstorm Wind in BURLEIGH, NORTH DAKOTA
From 15-AUG-11 20:10:00 to 15-AUG-11 20:20:00 (CST-6)
Location: (BIS)BISMARCK MUNI A
Magnitude: 62.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Hail in BURLEIGH, NORTH DAKOTA
From 15-AUG-11 20:15:00 to 15-AUG-11 20:20:00 (CST-6)
Location: BISMARCK
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Thunderstorm Wind in BURLEIGH, NORTH DAKOTA
From 15-AUG-11 20:30:00 to 15-AUG-11 20:35:00 (CST-6)
Location: FT LINCOLN
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Heavy rain accompanied the strong winds.

Thunderstorm Wind in ADAMS, NORTH DAKOTA
From 15-AUG-11 21:15:00 to 15-AUG-11 21:20:00 (MST-7)
Location: HETTINGER
Magnitude: 55.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Hail in BURLEIGH, NORTH DAKOTA
From 15-AUG-11 20:50:00 to 15-AUG-11 20:55:00 (CST-6)
Location: ARENA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flood in BURLEIGH, NORTH DAKOTA
From 15-AUG-11 20:20:00 to 16-AUG-11 00:45:00 (CST-6)
Location: BALDWIN
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Flooded roads were reported throughout Bismarck with water as much as two feet deep on streets. Water was running over curbs and through yards. Ditches in rural north Bismarck were full to overflowing and threatening homes. Two to three inches of rain fell on Bismarck. Rain at the airport measured 2.48 inches.

Hail in BOWMAN, NORTH DAKOTA
From 15-AUG-11 17:58:00 to 15-AUG-11 18:06:00 (MST-7)
Location: BUFFALO SPGS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter