An area of surface low pressure formed near Bismarck, North Dakota, late in the afternoon of June 7th, with a cold front extending to its north and south. Temperatures warmed nicely ahead of the front, with afternoon temperatures across southeast North Dakota topping out around 90F with dew point values around 60F. Thunderstorms formed in the warm sector across eastern North Dakota, some of them producing strong winds and large hail.

Thunderstorm Wind in CASS, NORTH DAKOTA
From 07-JUN-12 17:00:00 to 07-JUN-12 17:00:00 (CST-6)
Location: GARDNER
Magnitude: 50.00 EG
Reported by: Public

Several large tree branches were broken down in a shelterbelt.

Hail in TRAILL, NORTH DAKOTA
From 07-JUN-12 17:29:00 to 07-JUN-12 17:29:00 (CST-6)
Location: MAYVILLE
Magnitude: 1.25 
Reported by: Trained Spotter

Numerous quarter to walnut sized hail fell along with strong winds and brief heavy rains.

Hail in TRAILL, NORTH DAKOTA
From 07-JUN-12 17:50:00 to 07-JUN-12 17:50:00 (CST-6)
Location: MAYVILLE
Magnitude: 0.88 
Reported by: Public

A few dime to nickel sized hail fell.

Hail in GRAND FORKS, NORTH DAKOTA
From 07-JUN-12 18:34:00 to 07-JUN-12 18:34:00 (CST-6)
Location: MERRIFIELD
Magnitude: 1.00 
Reported by: Trained Spotter

Large hail and strong winds were reported.

Hail in GRAND FORKS, NORTH DAKOTA
From 07-JUN-12 18:52:00 to 07-JUN-12 18:52:00 (CST-6)
Location: GRAND FORKS
Magnitude: 0.75 
Reported by: Amateur Radio

Hail in RAMSEY, NORTH DAKOTA
From 07-JUN-12 19:20:00 to 07-JUN-12 19:20:00 (CST-6)
Location: DERRICK
Magnitude: 0.88 
Reported by: Public

A few nickel sized hail fell, but larger hail was likely into northwest Overland Township.

Hail in RAMSEY, NORTH DAKOTA
From 07-JUN-12 19:35:00 to 07-JUN-12 19:35:00 (CST-6)
Location: DERRICK
Magnitude: 1.00 
Reported by: Public

Thunderstorm Wind in CASS, NORTH DAKOTA
From 07-JUN-12 16:30:00 to 07-JUN-12 16:30:00 (CST-6)
Location: PROSPER
Magnitude: 50.00 EG
Reported by: Trained Spotter

Large branches were broken off trees at a farmstead.

Thunderstorm Wind in CASS, NORTH DAKOTA
From 07-JUN-12 16:40:00 to 07-JUN-12 16:40:00 (CST-6)
Location: ARGUSVILLE
Magnitude: 60.00 EG
Reported by: Broadcast Media

A semi tractor and trailer combination was blown off the interstate near the Argusville exit. The time was estimated from radar.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 07-JUN-12 18:05:00 to 07-JUN-12 18:05:00 (CST-6)
Location: REYNOLDS
Magnitude: 50.00 EG
Reported by: Public

A few large tree branches were broken down.

Thunderstorm Wind in NELSON, NORTH DAKOTA
From 07-JUN-12 18:50:00 to 07-JUN-12 18:50:00 (CST-6)
Location: MICHIGAN CITY
Magnitude: 50.00 EG
Reported by: Public

Several large tree branches were broken down in a shelterbelt.

Thunderstorm Wind in WALSH, NORTH DAKOTA
From 07-JUN-12 19:48:00 to 07-JUN-12 19:48:00 (CST-6)
Location: GRAFTON
Magnitude: 50.00 EG
Reported by: Trained Spotter

Four inch diameter tree branches were blown down.

Thunderstorm Wind in CAVALIER, NORTH DAKOTA
From 07-JUN-12 19:55:00 to 07-JUN-12 19:55:00 (CST-6)
Location: NEKOMA
Magnitude: 50.00 EG
Reported by: Public

Several large tree branches were blown down in a shelterbelt.

Hail in CASS, NORTH DAKOTA
From 07-JUN-12 16:30:00 to 07-JUN-12 16:30:00 (CST-6)
Location: PROSPER
Magnitude: 0.75 
Reported by: Trained Spotter

Wind driven hail caused brief whiteout conditions. Pea to dime sized hail covered the ground.

Hail in GRAND FORKS, NORTH DAKOTA
From 07-JUN-12 18:05:00 to 07-JUN-12 18:10:00 (CST-6)
Location: REYNOLDS
Magnitude: 0.75 
Reported by: Public

Pea to dime sized hail fell.

Hail in NELSON, NORTH DAKOTA
From 07-JUN-12 18:50:00 to 07-JUN-12 18:52:00 (CST-6)
Location: MICHIGAN CITY
Magnitude: 0.75 
Reported by: Public

Pea to dime sized hail fell.

Hail in CAVALIER, NORTH DAKOTA
From 07-JUN-12 19:55:00 to 07-JUN-12 19:57:00 (CST-6)
Location: NEKOMA
Magnitude: 0.75 
Reported by: Public

Pea to dime sized hail fell.