A strong upper level disturbance brought cold air and precipitation to North Central Montana. The cold air produced heavy snows in the high country (elevations above 6000 feet) of southwest Montana.
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 strong upper level disturbance brought cold air and precipitation to North Central Montana. The cold air produced heavy snows in the high country (elevations above 6000 feet) of southwest Montana. Accumulations of 8 to 15 inches were common.
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 May 21, 5:32 PM MST, 1 hour 34 minutes earlier.
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</html>4 heavy snow. Local standard time, as filed.
Snow accumulations of 9 inches were reported at the Copper Camp SNOTEL site (Lincoln 10NNW - elevation 6950 feet).
Snow accumulations of 14 inches were reported at the Rocker Peak SNOTEL site (Basin 6N - elevation 8000 feet).
Snow accumulations of 8 inches was reported at the Onion Park SNOTEL site(White Sulphur Springs 40N - elevation 7410 feet).
Snow accumulations of 8 inches were reported at the Crystal Lake SNOTEL site (Lewistown 18SSW - elevation 6050 feet).
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2007Every state in 2007This day in weather historyWarnings in Montana, May 2007
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: 31187, 31190, 31188, 31189.