A low pressure system from the Gulf of Alaska descended over the Rocky Mountain region, then moved northeast, emerging over the northern high plains. An arctic air mass from Alberta combined with wamer temperatures from the south to steer plentiful moisture through the area, bringing the first major winter storm of the season to northeast Motana.
Every event with a place to put it; 17 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 GGW wrote it up.
A low pressure system from the Gulf of Alaska descended over the Rocky Mountain region, then moved northeast, emerging over the northern high plains. An arctic air mass from Alberta combined with wamer temperatures from the south to steer plentiful moisture through the area, bringing the first major winter storm of the season to northeast Motana.
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 Glasgow, MT wrote its last area forecast discussion before the first event at Nov 8, 3:58 AM MST, 6 hours 2 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 358 AM MST THU NOV 8 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY... AN UPPER TROUGH STORM SYSTEM CHURNING OFF THE WEST COAST WILL SWING EAST OVER THE DIVIDE AND NORTHEAST MONTANA THROUGH THIS WEEKEND. OUT AHEAD OF THE STORM AN UPPER LEVEL DISTURBANCE TREKKING THROUGH SASKATCHEWAN AND MANITOBA SENT THE STATIONARY BOUNDARY SOUTH INTO NORTHEAST MONTANA WEDNESDAY NIGHT. THIS ACTED AS A COLD FRONT SENDING 850MB TEMPERATURES DOWN TO -4C TO -6C BY 18Z TODAY. THE WEST COAST TROUGH PICKS UP SIGNIFICANT AMOUNTS OF MOISTURE THAT WILL BE EJECTED BY THE BASE OF THE TROUGH NORTHEAST INTO MONTANA TODAY. SURFACE TEMPERATURES WILL NOT HAVE MUCH OF A CHANCE TO RECOVER AS THE COLD FRONT PLUNGES FURTHER SOUTH TODAY. THEREFORE EXPECT MOST PRECIPITATION NORTH OF THE MISSOURI RIVER TO BEGIN AS SNOW. ELSEWHERE COULD BE A MIX INITIALLY. THE UPPER JET WHICH TAKES AIM AT MOST OF THE STATE WILL NOT WAVER MUCH TODAY THROUGH FRIDAY. SO EXPECT THAT ONCE THE SNOW BEGINS IT WILL JUST CONTINUE THROUGH SATURDAY. THE BLIZZARD WINTER STORM HEADLINES BEGIN AT 18Z WHICH MIGHT BE A LITTLE EARLY BUT WILL ALLOW FOR ANY UNCERTAINTY OF WHEN THE SNOW STARTS FLYING. ALL THE MODELS RAMP UP QPF QUITE RAPIDLY AS THE DAY TRANSITIONS INTO EVENING. SNOW ACCUMULATIONS BEGIN TO AMPLIFY AFTER 00Z FRIDAY...ESPECIALLY FOR AREAS NORTH OF THE MISSOURI RIVER. ISENTROPIC LIFT REALLY RAMPS UP AT THIS TIME AS WELL...WITH 2 TO 3 G/KG MIXING RATIOS PUMPING IN EARLY AND POSSIBLY EVEN 4 G/KG BY 00Z SATURDAY FOR THE SOUTHEAST ZONES. STRONG Q VECTOR CONVERGENCE ALSO PASSES OVER THE REGION ON FRIDAY...AND CURRENTLY FRIDAY STILL LOOKS LIKE THE DAY WITH MOST OF THE ACCUMULATION OF SNOW FOR THE EVENT. FRIDAY THE 850MB TEMPERATURES BEGINS TO FALL AGAIN AS THE TROUGHS MOVES EAST. THEREFORE EXPECT THE MIXING RATIOS TO INCREASE. STORM TOTAL SNOW WILL RANGE FROM AROUND 6 TO 8 INCHES SOUTH OF THE MISSOURI RIVER TO AROUND 10 TO 15 INCHES NORTH OF THE RIVER. WIND STRENGTH IS A CHALLENGE SINCE IT WILL TAKE A WHILE FOR THE SURFACE PRESSURE GRADIENT TO RAMP UP. SIGNIFICANT SHEAR SAYS THAT WINDS WILL BE SURFACE BASED MOSTLY WITH THE LEE SURFACE TROUGH CENTER BEGINNING IN THE CENTRAL ROCKIES. SO WIND STRENGTH INITIALLY WILL NOT BE BLIZZARD STRENGTH BUT SHOULD BECOME STRONGER INTO THE EVENING AND FRIDAY. BUFKIT INDICATES 850MB WINDS SLOWLY RAMPING UP THURSDAY NIGHT AND BECOMING STRONGEST ON FRIDAY...THEN REACHING AROUND 40KTS BY FRIDAY NIGHT. THE 850MB WINDS WILL BE MIXING TO THE SURFACE WITH THE CAA. SO BLIZZARD CONDITIONS AND VISIBILITY COULD BE ACHIEVED TONIGHT THROUGH FRIDAY NIGHT NORTH OF THE MISSOURI RIVER. WINDS AND SNOW CONTINUE STRONG THROUGH SATURDAY. SO THE ENDING TIME OF THE HEADLINES AT 00Z SUNDAY LOOK GOOD FOR NOW. SCT .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY... SATURDAY NIGHT THE MAJOR WINTER STORM WILL BEGIN TO WIND DOWN WITH SNOWFALL RATES DECREASING ACROSS THE AREA FROM WEST TO EAST. THE 00Z RUN OF THE MODELS ARE A BIT MORE PROGRESSIVE IN MOVING THE SNOWFALL OUT OF THE CWA AND THIS TREND WILL BE WATCHED CLOSELY. FOR NOW THE THINKING IS THERE WILL STILL BE LINGERING LIGHT SNOW OR FLURRIES LINGERING ON SUNDAY MORNING...ESPECIALLY IN THE NORTHEASTERN PART OF OUR FORECAST AREA. REGARDLESS...WITH STRONG NORTHWEST WINDS THERE WILL STILL LIKELY BE BLOWING AND DRIFTING OF THE SNOW. NORTHWESTERLY FLOW AND MUCH COLDER TEMPERATURES...WELL BELOW AVERAGE...WILL BE LEFT IN THE WAKE OF THIS SYSTEM. SUNDAY NIGHT WILL FEATURE CLEARING SKIES FROM WEST TO EAST AS WELL AS SOME OF THE COLDEST TEMPERATURES OF THE SEASON SO FAR WITH MANY AREAS EXPECTED TO EXPERIENCE LOW TEMPERATURES NEAR OR BELOW ZERO. THEN FOR MONDAY AND TUESDAY AS AN UPPER LEVEL RIDGE BUILDS INTO THE AREA WEST TO NORTHWESTERLY CHINOOK WINDS WILL COME ACROSS THE DIVIDE AND TRY TO MODERATE TEMPERATURES. WITH A FRESH SNOW PACK IN PLACE HOWEVER...FEEL THAT MODELS ARE TOO BULLISH ON THIS TREND SO HAVE UNDERCUT GUIDANCE...PARTICULARLY IN THE FAVORED COOLER VALLEY REGIONS ACROSS THE MILK AND MISSOURI RIVERS. THERE THE SHALLOW COLDER AIR WILL PERSIST THOUGH HIGHER ELEVATIONS TO THE SOUTH AND WEST WILL MIX OUT AND EXPERIENCE MODERATING HIGHS BOTH MONDAY AND TUESDAY. THE ECMWF AND GFS SHOW THAT AS ANOTHER TROUGH BEGINS TO ENTER THE WESTERN U.S. ON WEDNESDAY THE RIDGE AXIS WILL BEGIN TO PROGRESS EAST OF OUR CWA SO MAY EXPERIENCE INCREASING CLOUD COVER TOWARD THE MIDDLE PORTION OF THE WEEK. MALIAWCO/EBERT && .AVIATION... COLD FRONT THAT SLID THROUGH THE REGION WEDNESDAY NIGHT HAS LEFT LOW CLOUDS OVER THE TAF SITES THIS MORNING. MVFR CONDITIONS ARE EXPECTED FOR MOST OF THE DAY WITH THIS LOW CLOUD LINGERING. FLIGHT CONDITIONS WILL DETERIORATE LATE IN THE DAY AS THE WINTER STORM SYSTEM MOVES INTO THE STATE. RAE && .GLASGOW WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING FROM 11 AM THIS MORNING TO 6 PM MST SATURDAY FOR PETROLEUM...GARFIELD. BLIZZARD WARNING FROM 11 AM THIS MORNING TO 6 PM MST SATURDAY FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...DANIELS...SHERIDAN...WESTERN ROOSEVELT...MCCONE... RICHLAND...NORTHERN PHILLIPS...SOUTHWEST PHILLIPS...NORTHERN VALLEY...EASTERN ROOSEVELT. WINTER STORM WARNING FROM 11 AM FRIDAY TO 6 PM MST SATURDAY FOR DAWSON...PRAIRIE...WIBAUX. && WEATHER.GOV/GLASGOW
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GLASGOW MT 357 AM MST THU NOV 8 2012 MTZ016>020-023-024-059>062-091100- CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY- DANIELS-SHERIDAN-WESTERN ROOSEVELT-MCCONE-RICHLAND- NORTHERN PHILLIPS-SOUTHWEST PHILLIPS-NORTHERN VALLEY- EASTERN ROOSEVELT- 357 AM MST THU NOV 8 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TODAY AND TONIGHT A BLIZZARD WARNING IS IN EFFECT THIS AFTERNOON THROUGH SATURDAY FOR SIGNIFICANT SNOWFALL AMOUNTS OF 12 TO 17 INCHES...AND BLOWING SNOW MAKING TRAVEL HAZARDOUS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME AFTER SUNDAY. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MTZ021-022-025>027-091100- PETROLEUM-GARFIELD-DAWSON-PRAIRIE-WIBAUX- 357 AM MST THU NOV 8 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TODAY AND TONIGHT A WINTER STORM WARNING IS IN EFFECT THIS AFTERNOON THROUGH SATURDAY FOR SIGNIFICANT SNOWFALL AMOUNTS OF OF 9 TO 14 INCHES AND BLOWING SNOW MAKING TRAVEL HAZARDOUS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME AFTER SUNDAY. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The national radar mosaic for the moment the first event began.
16 winter storm, 1 blizzard. Local standard time, as filed.
Spotters and cooperative observers reported around 6 inches of snowfall with slick road conditions due to brief freezing drizzle at the onset of the event.
A variety of spotter and cooperative reports confirmed snowfall totals of 5 to 10 inches across the county. Road conditions were also slick due to brief freezing drizzle at the onset of the event.
Cooperative observer at Zortman reported 7.5 inches of snow.
Cooperative observers reported 7 to 10 inches of snow across the area.
Multiple sources reported 8 to 12 inches of snow with a maximum storm total snowfall of 12.5 inches at the NWS office in Glasgow.
Snow reports of 5 to 6 inches were common across the area with a few observers reporting drifts 12 inches high.
Snow fall amounts of 10 to 12 inches were reported across this area with severe driving conditions being reported by the Montana Department of Transportation.
Snow reports of 6 inches were common across the area with freezing drizzle also reported in the late afternoon of the 9th.
The Morgan Port of Entry reported 9 inches of snow.
Snow reports of 6 to 9 inches were common across the area.
Cooperative observers and the county dispatch office reported the event began with freezing rain, which created slick roads, then changed over to snow with reports of 5 to 5.5 inches common across the area.
Multiple cooperative and CoCoRaHs observers reported a variety of 5 to 10 inches of snow fall while severe driving conditions were reported by the Montana Department of Transporation.
Cooperative observer in the town of Circle reported 6.5 inches of snow.
Cooperative observer reported 10 inches of snowfall in Terry with drifts up to 2 feet high. Icy road conditions were also reported from brief freezing drizzle at the onset of the event.
A variety of reports confirmed snowfall totals of 6 to 8 inches in the Yellowstone River Valley with amounts of 10 to 14 inches along the Big Sheep Mountains. Underlying slick road conditions were also reported due to some freezing drizzle at the onset of the event.
Cooperative observer in Wibaux reported 7 inches of snowfall. Other reports across the county included freezing drizzle, snow, and melting snow which caused very slick road conditions, resulting in an automobile accident on Interstate 94 with multiple fatalities. Two pregnant women, not wearing seatbelts, were killed when the vehicle rolled over off the interstate. Neither fetus survived. The driver was wearing a seatbelt and had some non-life threatening injuries.
Blizzard conditions were observed in Glasgow during the late morning hours with one-quarter mile visibility and 35 mph winds.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Winter Storm, Wibaux | 2012-11-09 | 19 | Female | Vehicle/Towed Trailer | Direct |
| Winter Storm, Wibaux | 2012-11-09 | 21 | Female | Vehicle/Towed Trailer | Direct |
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, November 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: 421663, 421661, 420999, 420998, 421018, 421026, 420854, 420992, 421000, 420996, 420997, 420977, 420991, 421645, 421660, 421638, 421670.