A surface low pressure combined with a moderately unstable atmosphere and and upper-level disturbance to support strong to severe thunderstorms over portions of northeast Montana.

Hail in PHILLIPS, MONTANA
From 05-AUG-13 14:05:00 to 05-AUG-13 14:05:00 (MST-7)
Location: LORING
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported half dollar sized hail.

Hail in VALLEY, MONTANA
From 05-AUG-13 15:50:00 to 05-AUG-13 15:50:00 (MST-7)
Location: BAYLOR
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported quarter-sized hail.

Hail in ROOSEVELT, MONTANA
From 05-AUG-13 16:43:00 to 05-AUG-13 16:43:00 (MST-7)
Location: POPLAR
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel-sized hail.

Thunderstorm Wind in RICHLAND, MONTANA
From 05-AUG-13 17:39:00 to 05-AUG-13 17:39:00 (MST-7)
Location: SIOUX PASS DOT
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter estimated 60 mph winds causing power surges in their home.

Hail in MCCONE, MONTANA
From 05-AUG-13 15:28:00 to 05-AUG-13 15:30:00 (MST-7)
Location: VIDA
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported golf ball sized hail.

Hail in GARFIELD, MONTANA
From 05-AUG-13 13:47:00 to 05-AUG-13 13:47:00 (MST-7)
Location: JORDAN
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported nickel-sized hail.

Hail in PHILLIPS, MONTANA
From 05-AUG-13 14:10:00 to 05-AUG-13 14:10:00 (MST-7)
Location: BOWDOIN
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel-sized hail.

Hail in ROOSEVELT, MONTANA
From 05-AUG-13 16:11:00 to 05-AUG-13 16:11:00 (MST-7)
Location: VOLT
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported penny-sized hail.

Thunderstorm Wind in ROOSEVELT, MONTANA
From 05-AUG-13 16:50:00 to 05-AUG-13 16:55:00 (MST-7)
Location: SPROLE
Magnitude: 59.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Taken at the Poplar RAWS station east of Poplar.

Thunderstorm Wind in RICHLAND, MONTANA
From 05-AUG-13 17:20:00 to 05-AUG-13 17:20:00 (MST-7)
Location: LAMBERT
Magnitude: 103.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Ten power poles that were only 1-2 years old were snapped by the powerful thunderstorm winds.

Thunderstorm Wind in RICHLAND, MONTANA
From 05-AUG-13 17:30:00 to 05-AUG-13 17:30:00 (MST-7)
Location: LAMBERT
Magnitude: 78.00 EG
Property damage: 150.00K
Reported by: NWS Storm Survey

Based on photos from emergency management and in discussion with those in the area, the wind speed is estimated to be at least 90 mph.  Trees were stripped of their leaves, windows were broken, There was a home with part of the roof torn off, windows broken a shed completely destroyed, and a nearly one hundred year old barn that had been restored in the past two years that was destroyed.

Thunderstorm Wind in RICHLAND, MONTANA
From 05-AUG-13 17:30:00 to 05-AUG-13 17:30:00 (MST-7)
Location: ENID
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported power poles knocked down.  Power not restored for several hours.

Hail in RICHLAND, MONTANA
From 05-AUG-13 17:27:00 to 05-AUG-13 17:27:00 (MST-7)
Location: ENID
Magnitude: 1.75 
Property damage: 2.00K
Reported by: Public

Public reported golf ball sized hail, a broken window, and crop damage.

Hail in RICHLAND, MONTANA
From 05-AUG-13 17:00:00 to 05-AUG-13 17:50:00 (MST-7)
Location: SIOUX PASS DOT
Magnitude: 1.50 
Property damage: 0.00K
Reported by: NWS Storm Survey

Reports from spotters, the public and emergency management indicate a very large area of significant crop loss about 5-10 miles either side of the line indicated.   Combined with some winds of up to 118 mph (estimated based on the damage photos), the hail and wind destroyed a large area of crops.  There are no good estimates of loss, but the few farmers we did speak to told us they lost thousands of acres, totaling in the millions of dollars of crop loss.

Thunderstorm Wind in ROOSEVELT, MONTANA
From 05-AUG-13 16:35:00 to 05-AUG-13 16:35:00 (MST-7)
Location: POPLAR ARPT
Magnitude: 60.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported they lost part of the roof of a steel outbuilding.

Thunderstorm Wind in ROOSEVELT, MONTANA
From 05-AUG-13 16:43:00 to 05-AUG-13 16:43:00 (MST-7)
Location: POPLAR ARPT
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported an antenna broken off their home and broken tree branches down.