A very unstable airmass allowed severe thunderstorms to develop over portions of Southwest Montana. Hail the size of golf balls and wind gusts in excess of 60 mph were reported in Beaverhead...Gallatin and Madison counties. Heavy rain also caused flash flooding in Beaverhead County.

Hail in MADISON, MONTANA
From 22-JUL-08 16:00:00 to 22-JUL-08 16:00:00 (MST-7)
Location: SHERIDAN
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm dropped .88 inch diameter hail at Sheridan 2W.

Thunderstorm Wind in MADISON, MONTANA
From 22-JUL-08 16:05:00 to 22-JUL-08 16:05:00 (MST-7)
Location: SHERIDAN
Magnitude: 61.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm produced a wind gust to 70 mph at Sheridan 2W.

Hail in GALLATIN, MONTANA
From 22-JUL-08 17:05:00 to 22-JUL-08 17:05:00 (MST-7)
Location: BOZEMAN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm dropped 1 inch diameter hail at Bozeman 5W.

Hail in GALLATIN, MONTANA
From 22-JUL-08 17:15:00 to 22-JUL-08 17:15:00 (MST-7)
Location: BOZEMAN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm dropped 1.75 inch diameter hail at Bozeman, just south of the Montana state University campus.

Hail in GALLATIN, MONTANA
From 22-JUL-08 15:15:00 to 22-JUL-08 15:15:00 (MST-7)
Location: BOZEMAN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm dropped 1 inch diameter hail at Bozeman 6S.

Hail in GALLATIN, MONTANA
From 22-JUL-08 17:20:00 to 22-JUL-08 17:20:00 (MST-7)
Location: BOZEMAN
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm dropped .75 inch diameter hail at Bozeman.

Thunderstorm Wind in GALLATIN, MONTANA
From 22-JUL-08 17:22:00 to 22-JUL-08 17:22:00 (MST-7)
Location: BELGRADE
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

A severe thunderstorm produced a wind gust to 58 mph at the Bozeman ASOS site.

Hail in GALLATIN, MONTANA
From 22-JUL-08 17:25:00 to 22-JUL-08 17:25:00 (MST-7)
Location: BOZEMAN
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

A severe thunderstorm dropped .75 inch diameter hail at Bozeman, near the downtown area. Power was reported out throughout the city.

Hail in GALLATIN, MONTANA
From 22-JUL-08 17:25:00 to 22-JUL-08 17:25:00 (MST-7)
Location: BOZEMAN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm dropped 1.75 inch diameter hail at Bozeman. Numerous homes on the south side of the city had broken windows.

Thunderstorm Wind in GALLATIN, MONTANA
From 22-JUL-08 17:20:00 to 22-JUL-08 17:20:00 (MST-7)
Location: BOZEMAN
Magnitude: 58.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm produced a wind gust to 67 mph at Bozeman 20N. The anemometer broke at 67 mph.

Hail in GALLATIN, MONTANA
From 22-JUL-08 14:11:00 to 22-JUL-08 14:11:00 (MST-7)
Location: BOZEMAN
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm dropped .75 inch diameter hail at Bozeman 1E.

Thunderstorm Wind in BEAVERHEAD, MONTANA
From 22-JUL-08 15:13:00 to 22-JUL-08 15:13:00 (MST-7)
Location: DILLON
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 Dillon.

Thunderstorm Wind in MADISON, MONTANA
From 22-JUL-08 16:09:00 to 22-JUL-08 16:09:00 (MST-7)
Location: ENNIS
Magnitude: 74.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A severe thunderstorm produced a wind gust to 85 mph at Ennis 1W. Many trees and power lines were reported downed in Ennis. A roof was also blown off a building in Ennis.

Hail in MADISON, MONTANA
From 22-JUL-08 15:30:00 to 22-JUL-08 15:30:00 (MST-7)
Location: SHERIDAN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm dropped 1.75 inch diameter hail at Sheridan. Hail broke nearly every window on the south and west facing sides of the Sheridan high school and elementary school. Many homes suffered substantial hail damage as did vehicles and crops.

Hail in BEAVERHEAD, MONTANA
From 22-JUL-08 15:10:00 to 22-JUL-08 15:10:00 (MST-7)
Location: DILLON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm dropped 1 inch diameter hail at Dillon 4W.

Flash Flood in BEAVERHEAD, MONTANA
From 22-JUL-08 15:32:00 to 22-JUL-08 19:30:00 (MST-7)
Location: DILLON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorms produced over six-tenths of an inch of rain in less than 20 minutes in Dillon. The resulting runoff caused water that was bumper deep on many streets in the city of Dillon.