A southwesterly flow ahead of a trough of low pressure situated over British Columbia transported abundant mid and upper level moisture into the region, while the lower levels remained dry. This combined with an unstable atmosphere created the conditions for isolated thunderstorms with a potential for strong to severe wind gusts.
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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 TFX wrote it up.
A southwesterly flow ahead of a trough of low pressure situated over British Columbia transported abundant mid and upper level moisture into the region, while the lower levels remained dry. This combined with an unstable atmosphere created the conditions for isolated thunderstorms with a potential for strong to severe wind gusts.
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 Great Falls, MT wrote its last area forecast discussion before the first event at Jul 31, 4:40 PM MST, 6 hours 5 minutes earlier.
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</html>The Great Falls radar (KTFX), 72 km away, was scanning. The volume nearest the first event began at 05:42 UTC.
1 thunderstorm wind. Local standard time, as filed.
Emergency management officials reported that a portion of a corrugated metal roof was blown off, with debris hitting a transformer and causing a power outage. The event time was estimated by radar.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2019Every state in 2019This day in weather historyWarnings in Montana, July 2019
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 2026-09-24. Each event’s entry at NCEI: 843930.