An upper level low along the California coast moved north toward Vancouver Island keeping southwest flow, moisture, and instability as fuel for isolated to scattered thunderstorms each afternoon and evening. Light winds at the surface caused storms to move quite slowly.

Thunderstorm Wind in BEAVERHEAD, MONTANA
From 12-AUG-13 15:47:00 to 12-AUG-13 15:47:00 (MST-7)
Location: GRANT
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

High winds measuring 51KT (59MPH) were reported 8 miles WSW of Grant, MT at the Brenner RAWS.

Heavy Rain in HILL, MONTANA
From 12-AUG-13 21:00:00 to 12-AUG-13 21:00:00 (MST-7)
Location: INVERNESS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Heavy rain estimated at about 1.40 inches fell during the evening hours.

Heavy Rain in HILL, MONTANA
From 12-AUG-13 21:00:00 to 12-AUG-13 21:00:00 (MST-7)
Location: RUDYARD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy rain estimated at about 2 inches fell during the evening hours.

Hail in PONDERA, MONTANA
From 10-AUG-13 20:15:00 to 10-AUG-13 20:15:00 (MST-7)
Location: HEART BUTTE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Hail measuring 1.00 inches (quarter sized) was reported covering the ground 1 mile NW of Heart Butte, MT.

Heavy Rain in CASCADE, MONTANA
From 10-AUG-13 23:00:00 to 11-AUG-13 00:00:00 (MST-7)
Location: GREAT FALLS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Heavy rain estimated at 1.00 inch in under an hour was reported to be flooding roads. Flooding was confirmed by law enforcement.

Hail in HILL, MONTANA
From 12-AUG-13 21:00:00 to 12-AUG-13 21:00:00 (MST-7)
Location: HAVRE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail measuring 1.00 inches (quarter sized) was reported 25 miles N of Havre, MT.

Hail in HILL, MONTANA
From 12-AUG-13 19:15:00 to 12-AUG-13 19:15:00 (MST-7)
Location: GILDFORD
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail measuring 1.50 inches (ping pong ball sized) was reported in Gildford, MT.

Hail in HILL, MONTANA
From 12-AUG-13 20:30:00 to 12-AUG-13 20:30:00 (MST-7)
Location: RUDYARD
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail measuring 1.00 inches (quarter sized) was reported 6 miles S of Rudyard, MT.

Hail in HILL, MONTANA
From 12-AUG-13 20:35:00 to 12-AUG-13 20:35:00 (MST-7)
Location: KREMLIN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail measuring 1.75 inches (golf ball sized) was reported 8 miles N of Kremlin, MT.

Hail in HILL, MONTANA
From 12-AUG-13 20:39:00 to 12-AUG-13 20:39:00 (MST-7)
Location: RUDYARD
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail measuring 1.25 inches (half dollar sized) was reported 16 miles SSE of Rudyard, MT.

Hail in HILL, MONTANA
From 12-AUG-13 20:45:00 to 12-AUG-13 20:45:00 (MST-7)
Location: INVERNESS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail measuring 1.00 inches (quarter sized) was reported 14 miles S of Inverness, MT.

Hail in HILL, MONTANA
From 12-AUG-13 21:00:00 to 12-AUG-13 21:00:00 (MST-7)
Location: HAVRE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail measuring 1.75 inches (golf ball sized) was reported 25 miles N of Havre, MT.

Hail in HILL, MONTANA
From 12-AUG-13 21:05:00 to 12-AUG-13 21:05:00 (MST-7)
Location: RUDYARD
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail measuring 1.50 inches (ping pong ball sized) was reported 6 miles SSE of Rudyard, MT.

Hail in GLACIER, MONTANA
From 10-AUG-13 16:30:00 to 10-AUG-13 16:30:00 (MST-7)
Location: BABB
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail measuring 1.00 inches (quarter sized) was reported 1 miles WNW of Babb, MT.