A very unstable and moist airmass allowed severe thunderstorms to develop during the late afternoon and early evening hours. Hail the size of half dollars and wind gusts in excess of 60 mph were reported.

Thunderstorm Wind in LEWIS AND CLARK, MONTANA
From 09-AUG-08 13:25:00 to 09-AUG-08 13:25:00 (MST-7)
Location: WOLF CREEK
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm produced a wind gust to 60 mph at Wolf Creek 3NNE.

Thunderstorm Wind in CASCADE, MONTANA
From 09-AUG-08 14:00:00 to 09-AUG-08 14:00:00 (MST-7)
Location: VAUGHN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A severe thunderstorm produced a wind gust to 60 mph at Vaughn.

Hail in BEAVERHEAD, MONTANA
From 09-AUG-08 14:36:00 to 09-AUG-08 14:36:00 (MST-7)
Location: LIMA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm dropped 1 inch diameter hail at Lima 3SE.

Thunderstorm Wind in PONDERA, MONTANA
From 09-AUG-08 14:36:00 to 09-AUG-08 14:36:00 (MST-7)
Location: VALIER
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm produced a wind gust to 70 mph at Valier.

Thunderstorm Wind in TOOLE, MONTANA
From 09-AUG-08 15:12:00 to 09-AUG-08 15:12:00 (MST-7)
Location: SHELBY
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm produced a wind gust to 60 mph at Shelby 2SE.

Thunderstorm Wind in PONDERA, MONTANA
From 09-AUG-08 14:35:00 to 09-AUG-08 14:35:00 (MST-7)
Location: CONRAD
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm produced a wind gust to 70 mph at Conrad 3SW.

Thunderstorm Wind in MADISON, MONTANA
From 09-AUG-08 15:35:00 to 09-AUG-08 15:35:00 (MST-7)
Location: CAMERON
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm produced a wind gust to 70 mph at Cameron 12S.

Thunderstorm Wind in HILL, MONTANA
From 09-AUG-08 17:00:00 to 09-AUG-08 17:00:00 (MST-7)
Location: SIMPSON
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm produced a wind gust to 60 mph at Simpson 5WNW.

Hail in BEAVERHEAD, MONTANA
From 09-AUG-08 12:15:00 to 09-AUG-08 12:15:00 (MST-7)
Location: LIMA
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A severe thunderstorm dropped 1.25 inch diameter hail at Lima 6ESE. The hail contributed to a vehicle accident on Interstate 15.

Thunderstorm Wind in LEWIS AND CLARK, MONTANA
From 09-AUG-08 13:15:00 to 09-AUG-08 13:15:00 (MST-7)
Location: AUGUSTA
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm produced a wind gust to 65 mph at Augusta 4W.

Thunderstorm Wind in TETON, MONTANA
From 09-AUG-08 13:50:00 to 09-AUG-08 13:50:00 (MST-7)
Location: CHOTEAU ARPT
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm produced a wind gust to 65 mph at Choteau Airport 1NE.

Thunderstorm Wind in BLAINE, MONTANA
From 09-AUG-08 18:00:00 to 09-AUG-08 18:00:00 (MST-7)
Location: CHINOOK
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm produced a wind gust to 60 mph at Chinook 7NE.

Hail in GALLATIN, MONTANA
From 09-AUG-08 18:03:00 to 09-AUG-08 18:03:00 (MST-7)
Location: BIG SKY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm dropped 1 inch diameter hail at Big Sky 2E.

Thunderstorm Wind in CHOUTEAU, MONTANA
From 09-AUG-08 15:01:00 to 09-AUG-08 15:01:00 (MST-7)
Location: HIGHWOOD
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A severe thunderstorm produced a wind gust to 64 mph at Highwood 7SW.