Tornado Watch Number 706 and Severe Thunderstorm Watch Number 707 were in effect for this event.
A strong capping inversion initially prevented storms from developing across North Dakota. Eventually, severe storms over northwest South Dakota continued to propagate northeast into far southwest and south central North Dakota during the mid to late evening as a surface warm front lifted north. These storms continued east and north into the early morning hours of August 1st, with additional development across the south central and southeast as a result of a strengthening low level jet. Most significant was the strong wind duration with these storms.
See the August 1 Storm Data entries.

Thunderstorm Wind in GRANT, NORTH DAKOTA
From 31-JUL-11 19:45:00 to 31-JUL-11 20:15:00 (MST-7)
Location: NEW LEIPZIG
Magnitude: 70.00 EG
Property damage: 500.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Large trees were blown down in the city of Carson. Structural damage also occurred to many local buildings in the city of Carson and surrounding farmsteads.

Thunderstorm Wind in BURLEIGH, NORTH DAKOTA
From 31-JUL-11 21:45:00 to 31-JUL-11 21:56:00 (CST-6)
Location: BISMARCK
Magnitude: 61.00 EG
Property damage: 35.00K
Crop damage: 0.00K
Reported by: NWS Employee

The strong thunderstorm winds snapped off two four inch in diameter trees.  An 8,000 pound fifth wheel camper was flipped over and destroyed.

Thunderstorm Wind in MORTON, NORTH DAKOTA
From 31-JUL-11 21:55:00 to 31-JUL-11 22:22:00 (CST-6)
Location: MANDAN
Magnitude: 61.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Heavy rain accompanied the strong winds. Trees were downed in Mandan.

Thunderstorm Wind in BURLEIGH, NORTH DAKOTA
From 31-JUL-11 21:56:00 to 31-JUL-11 22:24:00 (CST-6)
Location: (BIS)BISMARCK MUNI A
Magnitude: 59.00 MG
Property damage: 0.20K
Crop damage: 0.00K
Reported by: ASOS

This was the peak wind, 68 mph, measured at the National Weather Service ASOS at the Bismarck Airport during this severe thunderstorm. The wind gusted at or above 60 mph for 20 minutes. A small tree was snapped at the National Weather Service Office. Pea size hail accompanied the storm through Bismarck.

Thunderstorm Wind in BURLEIGH, NORTH DAKOTA
From 31-JUL-11 22:10:00 to 31-JUL-11 22:22:00 (CST-6)
Location: BISMARCK
Magnitude: 74.00 EG
Property damage: 35.00K
Crop damage: 0.00K
Reported by: NWS Employee

Winds were also estimated this high by law enforcement and Amateur Radio Operators. A trampoline was picked up by the strong winds and thrown into the side of a home in rural north Bismarck. Two 65 foot tall trees were snapped. Power flashes were occurring with the storm.

Thunderstorm Wind in BURLEIGH, NORTH DAKOTA
From 31-JUL-11 22:18:00 to 31-JUL-11 22:23:00 (CST-6)
Location: BISMARCK
Magnitude: 68.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in BURLEIGH, NORTH DAKOTA
From 31-JUL-11 22:35:00 to 31-JUL-11 22:53:00 (CST-6)
Location: STERLING
Magnitude: 70.00 EG
Property damage: 40.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The strong winds resulted in extensive tree damage throughout the town of Sterling.

Thunderstorm Wind in MCLEAN, NORTH DAKOTA
From 31-JUL-11 22:52:00 to 31-JUL-11 22:57:00 (CST-6)
Location: COLEHARBOR
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in FOSTER, NORTH DAKOTA
From 31-JUL-11 23:54:00 to 31-JUL-11 23:59:00 (CST-6)
Location: CARRINGTON
Magnitude: 61.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Broadcast Media

The strong winds blew down trees near Carrington.

Hail in ADAMS, NORTH DAKOTA
From 31-JUL-11 18:55:00 to 31-JUL-11 19:00:00 (MST-7)
Location: REEDER
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ADAMS, NORTH DAKOTA
From 31-JUL-11 19:20:00 to 31-JUL-11 19:25:00 (MST-7)
Location: BUCYRUS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in HETTINGER, NORTH DAKOTA
From 31-JUL-11 19:44:00 to 31-JUL-11 19:52:00 (MST-7)
Location: MOTT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in SIOUX, NORTH DAKOTA
From 31-JUL-11 19:15:00 to 31-JUL-11 19:25:00 (MST-7)
Location: SELFRIDGE
Magnitude: 70.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The very strong winds tore a small deck off of a house.

Flash Flood in BURLEIGH, NORTH DAKOTA
From 31-JUL-11 22:33:00 to 31-JUL-11 23:59:00 (CST-6)
Location: (BIS)BISMARCK MUNI A
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Numerous roads were reported to have over one foot of water on them.

Flash Flood in MORTON, NORTH DAKOTA
From 31-JUL-11 22:04:00 to 31-JUL-11 23:59:00 (CST-6)
Location: MANDAN
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: NWS Employee

Very heavy rain was creating flash flood conditions in Mandan.

Thunderstorm Wind in MORTON, NORTH DAKOTA
From 31-JUL-11 21:43:00 to 31-JUL-11 21:51:00 (CST-6)
Location: SWEET BRIAR
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio