A potent short wave trough moving across North Dakota combined with moderate instability to create an environment favorable for multicellular thunderstorms during the afternoon hours of the 12th. Above average precipitable water values ahead of the trough also increased the rainfall with the thunderstorms. Severe Thunderstorm Watch number 771 was in effect for this event.

Hail in LA MOURE, NORTH DAKOTA
From 12-AUG-11 14:25:00 to 12-AUG-11 14:29:00 (CST-6)
Location: ADRIAN
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in WELLS, NORTH DAKOTA
From 12-AUG-11 12:20:00 to 12-AUG-11 12:24:00 (CST-6)
Location: HAMBERG
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Hail in STUTSMAN, NORTH DAKOTA
From 12-AUG-11 13:31:00 to 12-AUG-11 13:36:00 (CST-6)
Location: SYDNEY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in STUTSMAN, NORTH DAKOTA
From 12-AUG-11 13:55:00 to 12-AUG-11 13:59:00 (CST-6)
Location: YPSILANTI
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Hail in STUTSMAN, NORTH DAKOTA
From 12-AUG-11 14:13:00 to 12-AUG-11 14:19:00 (CST-6)
Location: MONTPELIER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in STUTSMAN, NORTH DAKOTA
From 12-AUG-11 14:25:00 to 12-AUG-11 14:29:00 (CST-6)
Location: MONTPELIER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Hail in LA MOURE, NORTH DAKOTA
From 12-AUG-11 14:38:00 to 12-AUG-11 14:44:00 (CST-6)
Location: BERLIN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in LA MOURE, NORTH DAKOTA
From 12-AUG-11 14:45:00 to 12-AUG-11 14:51:00 (CST-6)
Location: LA MOURE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in LA MOURE, NORTH DAKOTA
From 12-AUG-11 15:00:00 to 12-AUG-11 15:06:00 (CST-6)
Location: MARION
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Flash Flood in STUTSMAN, NORTH DAKOTA
From 12-AUG-11 14:00:00 to 12-AUG-11 16:30:00 (CST-6)
Location: WOODWORTH
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: COOP Observer

Thunderstorms produced around two inches of rain in this area leading to flash flooding along low water crossings. Damage was minimal and confined to eroded road shoulders. Most of the rain fell in less than one hour.

Hail in STUTSMAN, NORTH DAKOTA
From 12-AUG-11 13:25:00 to 12-AUG-11 13:29:00 (CST-6)
Location: CLEVELAND
Magnitude: 1.00 
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Very heavy rain and strong winds up to 50 miles per hour accompanied the large hail.

Flash Flood in WELLS, NORTH DAKOTA
From 12-AUG-11 12:20:00 to 12-AUG-11 15:00:00 (CST-6)
Location: BOWDON
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: COOP Observer

Thunderstorms produced around two inches of rain in this area leading to flash flooding along low water crossings. Damage was minimal and confined to eroded road shoulders. One report was that most of the rain fell in a 20 minute period.