An impressive winter storm system moved into north central Idaho and western Montana on the 22nd and continued to effect the region through the 24th. Initially a steady stream of Pacific moisture moved in from the west.
Every event with a place to put it; 6 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 impressive winter storm system moved into north central Idaho and western Montana on the 22nd and continued to effect the region through the 24th. Initially a steady stream of Pacific moisture moved in from the west. This helped produce areas of heavy snowfall over the mountains and passes. The valleys received rain. As the main snowfall was ending a tight surface pressure gradient and a strong jet stream produced very strong winds.
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 22, 4:07 AM MST, 7 hours 53 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
407 AM MST WED FEB 22 2012
...HIGH WINDS EXPECTED MANY AREAS OF WESTERN MONTANA TODAY...
...HEAVY MOUNTAIN SNOW AND BLOWING SNOW DEVELOPING LATER TODAY AND
CONTINUING INTO TONIGHT...
.DISCUSSION...A POWERFUL UPPER LEVEL JET STREAM AND SURFACE COLD
FRONT WILL BE SAGGING SOUTH ACROSS THE NORTHERN ROCKIES REGION
TODAY CREATING A VARIETY OF WEATHER IMPACTS. THE FIRST IMPACT
SHOWS STRONG WESTERLY WINDS ASSOCIATED WITH THE COLD FRONT. TIMING
OF THE FRONT HAS IT MOVING THROUGH NORTHWEST MONTANA THIS
MORNING...WEST-CENTRAL MONTANA AND NORTH-CENTRAL IDAHO THIS
AFTERNOON. THE GREATEST WIND IMPACT IS EXPECTED THIS AFTERNOON IN
WESTERN MONTANA AND LEMHI COUNTY. THE FRONT SHOULD PRODUCE
CONVECTIVE BANDS FORCING SOME OF THE VERY STRONG WINDS ALOFT TO
THE SURFACE.
ANOTHER IMPACT OF THE VIGOROUS COLD FRONT WILL BE THE LOWERING OF
THE SNOW LEVELS WITH THE PRODUCTION OF HEAVY MOUNTAIN SNOW. SNOW
LEVELS WILL INITIALLY EXIST AT OR ABOVE MOUNTAIN PASS LEVELS THIS
MORNING...LOWERING DRAMATICALLY TO THE VALLEY FLOOR BY LATE THIS
AFTERNOON. STRONG WINDS THROUGH THE MOUNTAIN PASSES OF WESTERN
MONTANA ALONG WITH THE BURST OF HEAVY SNOW WITH THE COLD FRONT
SHOULD PRODUCE NEAR WHITEOUT CONDITIONS AT TIMES.
BEHIND THE COLD FRONT...BREEZY CONDITIONS SHOULD CONTINUE WITH
FALLING TEMPERATURES TONIGHT. THE PRECIPITATION SHOULD BECOME
MORE SCATTERED. HOWEVER...THE ATMOSPHERE SHOULD SUPPORT A FEW SNOW
BANDS OVERNIGHT WITH LOCAL VALLEY ACCUMULATIONS POSSIBLE.
A NORTHWEST FLOW IS EXPECTED TO CONTINUE THURSDAY WITH SOME
GRADUAL DRYING OF THE AIR MASS. HOWEVER...LIGHT SNOW SHOWERS WILL
CONTINUE OVER THE MOUNTAINS THANKS TO OROGRAPHIC ENHANCEMENT.
FRIDAY THROUGH MONDAY...A SHORT DRYING PERIOD FOR WESTERN MONTANA
EARLY ON FRIDAY. BUT THE NEXT WEATHER SYSTEM WILL BE DIGGING DOWN
THE BRITISH COLUMBIA COAST AND MOVING INTO NORTHWEST MONTANA OVER
NIGHT...AND SPREAD PRECIPITATION ACROSS WESTERN MONTANA AND NORTH
CENTRAL IDAHO ON SATURDAY. IT LOOKS LIKE THE PRECIPITATION WILL BE
IN THE FORM OF RAIN MIXED WITH SNOW IN THE VALLEYS WITH SNOW OVER
THE PASSES AND HIGHER PEAKS. BY SUNDAY SOME COLDER AIR MOVES INTO
THE REGION...WITH HIGH AND LOW TEMPERATURES ABOUT 5 DEGREES BELOW
NORMAL. THIS WILL BE COLD ENOUGH TO CHANGE THE RAIN/SNOW MIX OVER
TO ALL SNOW. ON MONDAY THE LOW MOVES OFF TO THE SOUTHEAST WITH A
NORTHERLY FLOW SETTING UP INTO WESTERN MONTANA.
&&
.AVIATION...MAIN IMPACTS WILL BE THE POTENTIAL FOR STRONG WINDS
DEVELOPING AT ALL TERMINALS TODAY. ONCE THE FRONTAL BOUNDARY
PUSHES SOUTH THE WINDS SHOULD PICK UP IN EARNEST. THERE IS THE
POTENTIAL FOR STRONGER WINDS GUSTS TO 45 KT AT KGPI BETWEEN
22/1800Z AND 22/2000Z...TO 50 KT AT BOTH KMSO AND KBTM ESPECIALLY
BETWEEN 22/1800Z AND 22/2300Z AND TO 50 KT AT KSMN BETWEEN
22/2000Z AND 23/0300Z. MODERATE TO SEVERE TURBULENCE WILL BE
EXPECTED ACROSS MUCH OF THE NORTHERN ROCKIES. WITH THE UNSTABLE
ATMOSPHERE LATER THIS EVENING INTO THE OVERNIGHT THERE WILL BE
SNOW SHOWERS AROUND AND COULD BRING LOWER CEILINGS AND
VISIBILITIES THAN FORECAST. MOUNTAIN OBSCURATIONS ARE EXPECTED
THROUGH THURSDAY MORNING.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT... HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON BUTTE/BLACKFOOT
REGION.
WINTER STORM WARNING UNTIL 5 AM MST THURSDAY ABOVE 5000 FEET FOR
THE BITTERROOT/SAPPHIRE MOUNTAINS.
HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON
MISSOULA/BITTERROOT VALLEYS.
WINTER STORM WARNING UNTIL 5 AM MST THURSDAY FOR I-90 LOOKOUT
PASS TO HAUGAN.
HIGH WIND WARNING UNTIL 1 PM MST THIS AFTERNOON FLATHEAD/MISSION
VALLEYS.
WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON ABOVE 5000
FEET FOR THE WEST GLACIER REGION.
WIND ADVISORY UNTIL 1 PM MST THIS AFTERNOON KOOTENAI/CABINET
REGION.
HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON POTOMAC/SEELEY
LAKE REGION.
ID...WINTER STORM WARNING UNTIL 5 AM MST THURSDAY FOR LOST TRAIL PASS.
WIND ADVISORY UNTIL 11 PM MST THIS EVENING EASTERN LEMHI
COUNTY...WESTERN LEMHI COUNTY.
WINTER STORM WARNING UNTIL 4 AM PST THURSDAY ABOVE 5000 FEET FOR
THE SOUTHERN CLEARWATER MOUNTAINS.
WIND ADVISORY UNTIL 8 AM PST THIS MORNING FOR THE CAMAS PRAIRIE
AND HIGHWAY 95 BETWEEN WHITE BIRD AND RIGGINS.
&&
SHORT TERM...MSJ
LONG TERM....MSJ
AVIATION...NOBLEPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
644 AM MST WED FEB 22 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0400 PM AVALANCHE 12 SE HUNGRY HORSE 48.26N 113.88W
02/20/2012 FLATHEAD MT LAW ENFORCEMENT
*** 1 FATAL *** SNOWMOBILE TRIGGERED AVALANCHE IN THE
LOST JOHNNY CREEK DRAINAGE...LOCATED IN THE SWAN MOUNTAIN
RANGE OF THE FLATHEAD NATIONAL FOREST.
&&
ALLEGRETTOPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
820 AM MST WED FEB 22 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0700 AM HEAVY RAIN THOMPSON FALLS 47.60N 115.34W
02/22/2012 M0.90 INCH SANDERS MT TRAINED SPOTTER
0700 AM HEAVY RAIN 9 NNW NOXON 48.12N 115.85W
02/22/2012 M1.40 INCH SANDERS MT TRAINED SPOTTER
&&
ALLEGRETTOThe national radar mosaic for the moment the first event began.
4 heavy snow, 1 strong wind, 1 high wind. Local standard time, as filed.
There was shingle damage in East Missoula to 25 homes.
A tree and billboard were blown down in Superior along with some shingle damage to the roof of an elementary school. Nearly 100 trees were reported to be blown down, some with their root balls attached and some snapped in half. Nine structures were damaged from falling trees, along with three homes and three moble homes. According to the fire chief, there were no injuries. The total swath of damage was estimated to be 6 miles long, from Superior east to mile marker 52 on I-90.
The ski resort at Lookout pass reported 14 inches of snow.
A 24 hour snowfall total of 10 inches was measured 1 mile south of Condon.
A 24 hour snowfall total of 9 inches was measured at Swan lake.
A 24 hour snowfall total of 10 inches was measured at Lake McDonald.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2012Every state in 2012This day in weather historyWarnings in Montana, February 2012
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: 367360, 367358, 366153, 367373, 367372, 367371.