An atmospheric river brought heavy snow and strong winds to the Clearwater and Bitterroot Mountains.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 MSO wrote it up.
An atmospheric river brought heavy snow and strong winds to the Clearwater and Bitterroot Mountains.
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 Missoula, MT wrote its last area forecast discussion before the first event at Dec 17, 1:25 PM MST, 21 hours 20 minutes earlier.
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</html>The national radar mosaic for the moment the first event began.
2 winter weather. Local standard time, as filed.
In Salmon, the COOP observer reported 5 inches of snowfall. Lost Trail Pass saw periods of heavy snow and blowing snow at times. The Moose Creek SNOTEL, located just south of the pass, reported 14 inches of snow depth increase during the storm.
The Idaho side of the Bitterroot crest absorbed heavy moisture from the atmospheric river, leading to high-impact winter conditions right along the Lolo Pass border. Further down the Highway 12 corridor at Powell, intense snowfall rates dropped 5 inches of snow in just a 6-hour period during the afternoon and evening of December 18. In Dixie, 6.5 inches of snow fell.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2025Every state in 2025This day in weather historyWarnings in Idaho, December 2025
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: 1307757, 1307754.