Severe Thunderstorm Watch number 550 was issued for much of west and north central North Dakota in the late afternoon hours of Thursday, July 29th. This was in anticipation of strong to severe thunderstorms over northeast Montana advecting east into western North Dakota Thursday evening along a trough of surface low pressure, with intensity sustained by an incoming mid level disturbance.
Isolated severe thunderstorms initially moved into northwest North Dakota early Thursday evening, with convective activity transitioning into linear segments during the mid to late evening hours before dissipating.
Multiple severe thunderstorm warnings were issued. Several reports of large hail and multiple reports of severe thunderstorm winds were received during this episode.

Thunderstorm Wind in WILLIAMS, NORTH DAKOTA
From 29-JUL-10 19:10:00 to 29-JUL-10 19:20:00 (CST-6)
Location: WILLISTON
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in MCKENZIE, NORTH DAKOTA
From 29-JUL-10 18:19:00 to 29-JUL-10 18:28:00 (MST-7)
Location: ALEXANDER
Magnitude: 61.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Law Enforcement

The strong thunderstorm winds resulted in a thirty foot elm tree blown down.

Hail in RENVILLE, NORTH DAKOTA
From 29-JUL-10 21:15:00 to 29-JUL-10 21:22:00 (CST-6)
Location: GRANO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in WILLIAMS, NORTH DAKOTA
From 29-JUL-10 17:47:00 to 29-JUL-10 17:54:00 (CST-6)
Location: WILLISTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in MCKENZIE, NORTH DAKOTA
From 29-JUL-10 19:20:00 to 29-JUL-10 19:30:00 (MST-7)
Location: GRASSY BUTTE
Magnitude: 61.00 EG
Property damage: 30.00K
Crop damage: 0.00K
Reported by: COOP Observer

The strong thunderstorm winds resulted in widespread tree damage, with numerous tree limbs broken off.

Thunderstorm Wind in MCLEAN, NORTH DAKOTA
From 29-JUL-10 21:57:00 to 29-JUL-10 22:02:00 (CST-6)
Location: GARRISON
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in MORTON, NORTH DAKOTA
From 29-JUL-10 22:14:00 to 29-JUL-10 22:22:00 (CST-6)
Location: HEBRON
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Estimated winds of 70 mph were reported.

Thunderstorm Wind in MCKENZIE, NORTH DAKOTA
From 29-JUL-10 19:30:00 to 29-JUL-10 19:40:00 (MST-7)
Location: GRASSY BUTTE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy rain accompanied the strong thunderstorm winds.

Thunderstorm Wind in DUNN, NORTH DAKOTA
From 29-JUL-10 20:27:00 to 29-JUL-10 20:36:00 (MST-7)
Location: HALLIDAY
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Estimated winds of 60 mph were reported.

Thunderstorm Wind in MCLEAN, NORTH DAKOTA
From 29-JUL-10 21:06:00 to 29-JUL-10 21:15:00 (CST-6)
Location: ROSEGLEN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy rain accompanied the strong thunderstorm winds.

Thunderstorm Wind in MERCER, NORTH DAKOTA
From 29-JUL-10 22:09:00 to 29-JUL-10 22:15:00 (CST-6)
Location: HAZEN
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in MCLEAN, NORTH DAKOTA
From 29-JUL-10 21:55:00 to 29-JUL-10 22:03:00 (CST-6)
Location: GARRISON
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Estimated winds of 60 mph were reported.

Lightning in WILLIAMS, NORTH DAKOTA
From 29-JUL-10 19:30:00 to 29-JUL-10 19:30:00 (CST-6)
Location: WILLISTON
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Newspaper

Lightning struck a mobile home in Williston, resulting in a fire to the residence. Nobody was injured in the fire.

Thunderstorm Wind in MERCER, NORTH DAKOTA
From 29-JUL-10 21:54:00 to 29-JUL-10 22:06:00 (CST-6)
Location: BEULAH
Magnitude: 52.00 EG
Property damage: 70.00K
Crop damage: 0.00K
Reported by: Newspaper

Estimated winds of 60 mph were reported. A light pole at a gas station in Beulah was blown over, along with several trees in the town of Beulah blown down. Blown over trees or branches knocked utility lines to the ground, momentarily disrupting power.

Hail in WILLIAMS, NORTH DAKOTA
From 29-JUL-10 18:15:00 to 29-JUL-10 18:24:00 (CST-6)
Location: EPPING
Magnitude: 2.50 
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The large hail resulted in borken windows in the town of Epping.

Thunderstorm Wind in RENVILLE, NORTH DAKOTA
From 29-JUL-10 21:16:00 to 29-JUL-10 21:23:00 (CST-6)
Location: NORMA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Estimated winds of 60 mph were reported.

Thunderstorm Wind in STARK, NORTH DAKOTA
From 29-JUL-10 21:13:00 to 29-JUL-10 21:21:00 (MST-7)
Location: DICKINSON
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Estimated winds of 70 mph were reported.