An upper trough moving east into the Pacific Northwest and bumping into a warm and unstable airmass over eastern Montana triggered severe thunderstorms mainly after sunset. Heavy rain also occurred in an area that produced flash flooding.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS GGW wrote it up.
An upper trough moving east into the Pacific Northwest and bumping into a warm and unstable airmass over eastern Montana triggered severe thunderstorms mainly after sunset. Heavy rain also occurred in an area that produced flash flooding.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Glasgow, MT wrote its last area forecast discussion before the first event at Jul 1, 1:45 PM MST, 5 hours 11 minutes earlier.
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</html>The Glasgow radar (KGGW), 68 km away, was scanning. The volume nearest the first event began at 01:56 UTC.
12 thunderstorm wind, 1 lightning, 1 flash flood. Local standard time, as filed.
A spotter in the Hell Creek Recreation Area reported strong winds ahead of the thunderstorms.
The Fort Peck Handar Observation Site reported this wind gust above the intake buildings at Fort Peck Dam.
Brief severe winds caused small tree branches to break off of trees.
Tree hit by lightning on Second Ave North in Glasgow landed on a car.
A shelf cloud came through Glasgow producing brief winds of 55 to 60 mph. A forty foot section of metal roof off of an airport hanger building was peeled back and blown approximately 75 yards to the north. A large highway sign was blown off and shredded along Highway 2 east of Glasgow.
Neighbor of a trained spotter reported two feet of water flowing over Highway 200 between Circle and Flowing Wells Rest Area.
Severe winds blowing through town with yard and garbage debris blowing throughout the city.
NWS Employee estimated wind at 65 to 70 mph. Strong wind damaged sliding glass door 6 miles east of Larslan.
Spotter (located 1 mile north of the Flowing Wells Rest Area) reported 58 mph wind gust.
Small tree branches breaking out of trees in town.
Mesonet site W7PG-11 recorded the wind gust.
Awning torn off of a home and flipped up on the roof by severe winds.
One inch diameter tree limbs broken off. Larger dead tree limbs of 6 to 8 inches broken off.
Spotter 14 miles south-southeast of Culbertson estimated a wind gust of 60 mph at 2223 MST which blew over a 15 foot grain hopper. At 2339 MST, Sioux Pass DOT sensor recorded a wind gust of 58 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2010Every state in 2010This day in weather historyWarnings in Montana, July 2010
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 238336, 254627, 254629, 243008, 254628, 238447, 254630, 238341, 238437, 254631, 238440, 254632, 254633, 238443.