A Supercell thunderstorm formed in northern Phillips County near Whitewater and moved southeast through the Glasgow area (Valley County). The storm quickly dissipated southeast of Glasgow in northern McCone County.

Hail in PHILLIPS, MONTANA
From 28-JUL-10 16:55:00 to 28-JUL-10 16:55:00 (MST-7)
Location: WHITEWATER
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reported nickel size hail.

Hail in PHILLIPS, MONTANA
From 28-JUL-10 17:15:00 to 28-JUL-10 17:15:00 (MST-7)
Location: WHITEWATER
Magnitude: 1.00 
Property damage: 0.00K
Reported by: Trained Spotter

Hail up to one inch in size was reported.  The hail was a foot deep in some areas.

Thunderstorm Wind in VALLEY, MONTANA
From 28-JUL-10 19:15:00 to 28-JUL-10 19:15:00 (MST-7)
Location: GLASGOW
Magnitude: 65.00 MG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer reported damage to windows and siding of his home with winds of 75 mph and three-quarter inch hail.

Hail in PHILLIPS, MONTANA
From 28-JUL-10 17:20:00 to 28-JUL-10 17:20:00 (MST-7)
Location: WHITEWATER
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in VALLEY, MONTANA
From 28-JUL-10 18:10:00 to 28-JUL-10 18:10:00 (MST-7)
Location: HINSDALE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

At 1810 MST 10 miles southeast of Frenchmen Reservoir, hail fell with 40 mph winds.

Hail in VALLEY, MONTANA
From 28-JUL-10 19:15:00 to 28-JUL-10 19:15:00 (MST-7)
Location: GLASGOW
Magnitude: 0.75 
Crop damage: 0.00K
Reported by: Trained Spotter

A thunderstorm wind gust to 75 mph combined with the hail to break windows and damage siding.

Hail in VALLEY, MONTANA
From 28-JUL-10 18:57:00 to 28-JUL-10 18:57:00 (MST-7)
Location: VANDALIA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in VALLEY, MONTANA
From 28-JUL-10 18:10:00 to 28-JUL-10 18:10:00 (MST-7)
Location: HINSDALE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter size hail reported.

Hail in PHILLIPS, MONTANA
From 28-JUL-10 18:15:00 to 28-JUL-10 18:15:00 (MST-7)
Location: SACO
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Penny size hail reported by Frenchman Dam caretakers.

Thunderstorm Wind in VALLEY, MONTANA
From 28-JUL-10 18:28:00 to 28-JUL-10 18:28:00 (MST-7)
Location: HINSDALE
Magnitude: 65.00 EG
Crop damage: 0.00K
Reported by: NWS Storm Survey

An older barn north of Hinsdale had the metal roof sheeting peeled off and thrown downstream by straight line winds. Several round hail bales were rolled, and many tree branches were broken.

Heavy Rain in PHILLIPS, MONTANA
From 28-JUL-10 16:30:00 to 28-JUL-10 16:45:00 (MST-7)
Location: WHITEWATER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall of 1.62 inches along with .25 hail fell with the thunderstorm.

Hail in PHILLIPS, MONTANA
From 28-JUL-10 16:55:00 to 28-JUL-10 16:55:00 (MST-7)
Location: WHITEWATER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

At 1655 MST 5 miles north of Whitewater, a spotter reported one inch hail.

Thunderstorm Wind in VALLEY, MONTANA
From 28-JUL-10 19:38:00 to 28-JUL-10 19:50:00 (MST-7)
Location: GLASGOW
Magnitude: 74.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: NWS Employee

At 1938, 2 miles northwest of Glasgow, numerous large tree branches of 6 inches plus in diameter and 15 to 25 feet long were snapped off of trees with severe winds and one inch hail.  The winds and hail lasted for 12 minutes.  Minor damage was reported in the area with some siding, windows and shingle damage to homes.  The home of the NWS employee received new shingles and sky lights.  Another NWS employee nearby had the seals on their windows broken.

Hail in VALLEY, MONTANA
From 28-JUL-10 19:35:00 to 28-JUL-10 19:55:00 (MST-7)
Location: GLASGOW
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Two NWS employees and the NWS office all reported one inch hail.

Hail in VALLEY, MONTANA
From 28-JUL-10 19:17:00 to 28-JUL-10 19:17:00 (MST-7)
Location: TAMPICO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Cooperative Weather Observer reported quarter size hail at Tampico.

Flash Flood in VALLEY, MONTANA
From 28-JUL-10 19:44:00 to 28-JUL-10 20:05:00 (MST-7)
Location: GLASGOW
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Six miles west of Glasgow at 1944 MST, water flowed over the road. At 2005 MST 2 miles northwest of Glasgow NWS employee reported 1.8 of rain fell in 25 minutes. Also, flash flooding occurred in Glasgow, where the 6th Street underpass and the parking lots of the Gordon's Grocery and Town and County Furniture stores were several feet under water.  WFO Glasgow rainfall total was 1.15 inches in 25 minutes.