The combination of a moist Pacific storm system and the intrusion of cold Arctic air produced a wide range of weather conditions. Strong gusty winds produced very cold wind chill temperatures.
Every event with a place to put it; 12 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.
The combination of a moist Pacific storm system and the intrusion of cold Arctic air produced a wide range of weather conditions. Strong gusty winds produced very cold wind chill temperatures. Heavy snow and wind produced areas of blowing snow, along with isolated near blizzard condition.
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 Feb 21, 2:57 PM MST, 6 hours 3 minutes earlier.
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</html>The national radar mosaic for the moment the first event began.
11 heavy snow, 1 extreme cold/wind chill. Local standard time, as filed.
Snowfall of 11.4 inches was measured 2 miles northwest of Heron Montana.
Snowfall was measured at 9 inches northeast of Essex Montana. At 830 am the snow was falling at a rate of 1 inch per hour.
Snowfall was measured at 13 inches by a trained spotter, 6 miles south-southwest of Eureka Montana.
A listener called in to a local tv station estimating snowfall of 13 inches in Eureka Montana.
Heavy snow measured at 11 inches was reported 5 miles north-northwest of Eureka Montana.
Estimated snowfall of 8 inches at the fire department in Eureka Montana.
Heavy snow measured at 6.6 inches was reported in Troy Montana.
Snowfall estimated at 6 inches in Troy Montana.
Snowfall measured at 8 inches was reported 5 miles southeast of Yaak Montana.
Snowfall was measured at 7 inches 9 miles north-northeast of Yaak Montana.
Snowfall was estimated at 5 inches in Libby Montana. Libby sheriff dispatch reported accidents across the town.
Temperatures of -4 to -5 degrees F, along with wind gusts of 15 to 29 mph produced wind chill temperatures 20 below zero degrees F at Esses Montana on US highway 2.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2011Every state in 2011This day in weather historyWarnings in Montana, February 2011
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: 280128, 280127, 280103, 280108, 280114, 280117, 280119, 280121, 280123, 280125, 280126, 280129.