In the mid-evening hours of Monday, June 21st, Severe Thunderstorm Watch 375 was issued for ongoing severe thunderstorms over eastern Montana advecting east into western North Dakota, and in anticipation of further convective development and intensification across west and central North Dakota into the early morning hours of Tuesday, June 22nd.
Strengthening low level warm air advection along a northward surging warm front, combined with divergent flow aloft ahead of an approaching mid level short wave trough, were the key ingredients for severe convection.  Multiple severe thunderstorm warnings were issued, along with several flood advisories for excessive rainfall. Four reports of large hail and numerous reports of severe thunderstorm wind gusts were received.

Hail in MCKENZIE, NORTH DAKOTA
From 21-JUN-10 22:17:00 to 21-JUN-10 22:21:00 (MST-7)
Location: KEENE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Heavy Rain in BURLEIGH, NORTH DAKOTA
From 22-JUN-10 01:35:00 to 22-JUN-10 01:35:00 (CST-6)
Location: BISMARCK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Two inches of heavy rain resulted in the two underpasses in Bismarck to become flooded, with cars stalled in the underpasses.

Hail in STUTSMAN, NORTH DAKOTA
From 22-JUN-10 02:48:00 to 22-JUN-10 02:52:00 (CST-6)
Location: ELDRIDGE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MCKENZIE, NORTH DAKOTA
From 21-JUN-10 19:56:00 to 21-JUN-10 20:06:00 (MST-7)
Location: FAIRVIEW
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in MCKENZIE, NORTH DAKOTA
From 21-JUN-10 21:45:00 to 21-JUN-10 21:50:00 (MST-7)
Location: GRASSY BUTTE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Thunderstorm Wind in BOWMAN, NORTH DAKOTA
From 21-JUN-10 20:43:00 to 21-JUN-10 20:53:00 (MST-7)
Location: RHAME
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 BOWMAN, NORTH DAKOTA
From 21-JUN-10 21:02:00 to 21-JUN-10 21:16:00 (MST-7)
Location: GRIFFIN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Strong thunderstorm winds were also reported across southern Bowman County.

Thunderstorm Wind in ADAMS, NORTH DAKOTA
From 21-JUN-10 21:40:00 to 21-JUN-10 21:50:00 (MST-7)
Location: HETTINGER
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in HETTINGER, NORTH DAKOTA
From 21-JUN-10 22:40:00 to 21-JUN-10 22:50:00 (MST-7)
Location: MOTT
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Heavy rain accompanied the strong thunderstorm winds.

Thunderstorm Wind in SIOUX, NORTH DAKOTA
From 21-JUN-10 23:30:00 to 21-JUN-10 23:40:00 (MST-7)
Location: SELFRIDGE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

No hail was reported with the strong thunderstorm winds.

Thunderstorm Wind in MORTON, NORTH DAKOTA
From 22-JUN-10 01:30:00 to 22-JUN-10 01:40:00 (CST-6)
Location: MANDAN
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in EMMONS, NORTH DAKOTA
From 22-JUN-10 01:45:00 to 22-JUN-10 02:00:00 (CST-6)
Location: HAZELTON
Magnitude: 70.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Newspaper

The intense thunderstorm winds resulted in damage to tree branches in Hazelton, along with minor damage to one home.

Thunderstorm Wind in STUTSMAN, NORTH DAKOTA
From 22-JUN-10 02:57:00 to 22-JUN-10 03:10:00 (CST-6)
Location: PINGREE
Magnitude: 61.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Newspaper

The strong thunderstorm winds resulted in a pole barn overturned on a farmstead south of Pingree.

Thunderstorm Wind in SIOUX, NORTH DAKOTA
From 22-JUN-10 00:25:00 to 22-JUN-10 00:35:00 (MST-7)
Location: SELFRIDGE
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

Recorded at the Tatanka Prairie Remote Automated Weather Station.

Thunderstorm Wind in BURLEIGH, NORTH DAKOTA
From 22-JUN-10 02:00:00 to 22-JUN-10 02:15:00 (CST-6)
Location: MOFFIT
Magnitude: 71.00 MG
Property damage: 30.00K
Crop damage: 0.00K
Reported by: RAWS

Recorded at the Long Lake National Wildlife Refuge Remote Automated Weather Station.  The intense thunderstorm winds created four to five foot high waves on Long Lake, resulting in damage to dikes and railroad ties along the lake shore. No reports of other damage to structures in the area were received.

Thunderstorm Wind in ADAMS, NORTH DAKOTA
From 21-JUN-10 22:06:00 to 21-JUN-10 22:16:00 (MST-7)
Location: HETTINGER
Magnitude: 57.00 MG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: ASOS

The strong thunderstorm winds resulted in minor tree damage in Hettinger, along with minor damage to one home.

Thunderstorm Wind in STUTSMAN, NORTH DAKOTA
From 22-JUN-10 02:53:00 to 22-JUN-10 03:03:00 (CST-6)
Location: ELDRIDGE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

No hail was reported with the strong thunderstorm winds.