The largest severe weather outbreak of the summer occurred during the afternoon and evening hours of the 7th. A moist and very unstable atmosphere was in place across South Central and Southeast Montana. An upper level disturbance combined with a cool front moving across the Billings County Warning Area allowed for the development of severe thunderstorms producing high winds and large hail. Very heavy rain also accompanied the thunderstorms.

Hail in MUSSELSHELL, MONTANA
From 07-AUG-09 16:30:00 to 07-AUG-09 16:30:00 (MST-7)
Location: ELSO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in BIG HORN, MONTANA
From 07-AUG-09 16:45:00 to 07-AUG-09 16:45:00 (MST-7)
Location: KIRBY
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ROSEBUD, MONTANA
From 07-AUG-09 17:30:00 to 07-AUG-09 17:30:00 (MST-7)
Location: BIRNEY
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ROSEBUD, MONTANA
From 07-AUG-09 17:35:00 to 07-AUG-09 17:35:00 (MST-7)
Location: BIRNEY
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in CARTER, MONTANA
From 07-AUG-09 19:15:00 to 07-AUG-09 19:15:00 (MST-7)
Location: EKALAKA
Magnitude: 61.00 EG
Crop damage: 0.00K
Reported by: Trained Spotter

Winds were estimated to be around 70 mph. This combined with hail resulted in damage to the siding of a house and windows being blown out on the west side.

Hail in CARTER, MONTANA
From 07-AUG-09 19:42:00 to 07-AUG-09 19:42:00 (MST-7)
Location: EKALAKA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CARTER, MONTANA
From 07-AUG-09 19:50:00 to 07-AUG-09 19:50:00 (MST-7)
Location: EKALAKA ARPT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CARTER, MONTANA
From 07-AUG-09 19:50:00 to 07-AUG-09 19:50:00 (MST-7)
Location: EKALAKA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm Wind in ROSEBUD, MONTANA
From 07-AUG-09 20:05:00 to 07-AUG-09 20:05:00 (MST-7)
Location: THURLOW
Magnitude: 59.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Hail in FALLON, MONTANA
From 07-AUG-09 20:18:00 to 07-AUG-09 20:18:00 (MST-7)
Location: WEBSTER
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ROSEBUD, MONTANA
From 07-AUG-09 17:57:00 to 07-AUG-09 17:57:00 (MST-7)
Location: ASHLAND
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CUSTER, MONTANA
From 07-AUG-09 18:55:00 to 07-AUG-09 18:55:00 (MST-7)
Location: MILES CITY
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CUSTER, MONTANA
From 07-AUG-09 18:57:00 to 07-AUG-09 18:57:00 (MST-7)
Location: ULMER
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in FALLON, MONTANA
From 07-AUG-09 19:00:00 to 07-AUG-09 19:00:00 (MST-7)
Location: WESTMORE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Hail in CUSTER, MONTANA
From 07-AUG-09 19:14:00 to 07-AUG-09 19:14:00 (MST-7)
Location: KNOWLTON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in FALLON, MONTANA
From 07-AUG-09 19:15:00 to 07-AUG-09 19:15:00 (MST-7)
Location: WESTMORE
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts were also estimated at 60 mph.

Thunderstorm Wind in CUSTER, MONTANA
From 07-AUG-09 20:48:00 to 07-AUG-09 20:48:00 (MST-7)
Location: MILES CITY
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Hail in CUSTER, MONTANA
From 07-AUG-09 20:49:00 to 07-AUG-09 20:49:00 (MST-7)
Location: MILES CITY
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in POWDER RIVER, MONTANA
From 07-AUG-09 18:00:00 to 07-AUG-09 18:00:00 (MST-7)
Location: OTTER
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

Firefighters reported golfball size hail that broke windows on several vehicles.