High winds were measured over the Northern Rocky Mountain Front as well as Central and Southwest Montana mountains.
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.
High winds were measured over the Northern Rocky Mountain Front as well as Central and Southwest Montana 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 Great Falls, MT wrote its last area forecast discussion before the first event at Dec 20, 12:40 AM MST, 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 1240 AM MST Thu Dec 20 2012 .UPDATE... TONIGHT...Winds continue to increase along the Northern Rocky Mountain Front and are nearing High Wind criteria. Have updated to issue a warning through 5 AM MST Friday and to add a mention of blowing snow across this region. mpj && .AVIATION... .Updated 0528Z... VFR conditions will prevail over the next 24 hours. At all TAF sites...winds will increase overnight across the Rocky Mountain Front and adjacent high plains. Clouds will generally increase throughout the TAF period...however ceiling heights should remain above VFR restrictions. Suk && .PREV DISCUSSION... /ISSUED 445 PM MST Wed Dec 19 2012/ Tonight through Thursday...Atmospheric moisture will increase over the Rocky Mountain Front tonight as a strong mid-level jet stream pulls Pacific moisture into the area. Lift associated with the jet and lift over the terrain will result in widespread snow late tonight through Thursday near the continental divide over the Northern Rocky Mountain Front. The NAM and SREF models are most aggressive, forecasting locations near the divide to receive between one half and one inch of precipitation through the period. Meanwhile, the GFS is drier with one half inch or less. The NAM and SREF seem reasonable given the amount of moisture and lift in this area. Relied upon a blend of the NAM and SREF for precipitation, resulting in forecast snow amounts of 6 to 12 inches near the divide in the Northern Rocky Mountain Front tonight through Thursday evening. Issued a winter storm warning for this area with the main impacts being heavy snow and blowing snow. Lighter snow showers will affect the southern areas of the Rocky Mountain Front with a few inches of accumulation expected. Further east of the divide, dry weather should prevail due to breezy downslope winds. Langlieb Thursday night through Friday...Upper low off coast Pac NW deepens as ridge over eastern MT strengthens leaving CWA under southwest flow aloft. Mid- and upper-level moisture will result in mostly cloudy skies, but lower-level moisture will largely be confined to the continental divide and westward. While breezy downslope winds will tend to mitigate precipitation along the east slopes, isolated showers are possible over the mountains of central and southwest Montana. Temperatures will remain above seasonal normals both periods. Britton Friday Night through Wednesday...Southwest flow aloft will bring increasing moisture to the Continental Divide Friday night and Saturday as a trough of low pressure moves into the Pacific Northwest. A cold Canadian airmass will result in the northern zones having below normal temperatures Saturday while southwest Montana will have highs near normal. By Sunday, the cold airmass will push farther south. There is still a fair amount of uncertainty in the long-range models regarding precipitation amounts, temperatures and timing. The latest ECMWF has trended colder but the inherited forecast is in line with this colder trend. Models show differences regarding precipitation amounts and for now have kept the best chance for precipitation in the mountains across southwest Montana. Given the model differences and run-to-run inconsistencies, forecast confidence remains low and will not favor one model solution over the other and keep the forecast cooler than average with increased precipitation chances. MLV/Blank && .PRELIMINARY POINT TEMPS/POPS... GTF 20 41 26 41 / 0 0 0 10 CTB 16 42 21 36 / 10 10 10 10 HLN 10 35 17 37 / 0 10 10 10 BZN 3 30 11 35 / 0 0 10 10 WEY -9 22 3 27 / 20 10 20 10 DLN 8 31 15 36 / 10 10 20 20 HVR 11 36 18 34 / 0 0 0 10 LWT 10 38 21 41 / 0 0 0 10 && .TFX WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING until 5 PM MST Thursday FOR ELEVATIONS ABOVE 5500 FEET FOR Northern Rocky Mountain Front. HIGH WIND WARNING until 5 AM MST Friday Northern Rocky Mountain Front. HIGH WIND WARNING from 2 AM Thursday to 11 AM MST Friday Madison. && weather.gov/greatfalls
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREAT FALLS MT 942 PM MST WED DEC 19 2012 MTZ015-201215- MADISON- 942 PM MST WED DEC 19 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST MONTANA. .DAY ONE...THIS AFTERNOON AND TONIGHT A HIGH WIND WARNING IS IN EFFECT FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR THE NORRIS HILL AREA. SOUTHWEST WINDS 30 TO 40 MPH WITH GUSTS TO 60 MPH ARE EXPECTED. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THE HIGH WIND WARNING CONTINUES THROUGH THURSDAY NIGHT. THE POTENTIAL EXISTS FOR COLDER TEMPERATURES AND A CHANCE FOR LIGHT SNOW ACROSS THE REGION SUNDAY THROUGH MONDAY. HOWEVER... CONFIDENCE IN THE TEMPERATURE RANGE AND SNOWFALL AMOUNTS REMAINS LOW AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. MTZ008-010>014-044>055-201215- BEAVERHEAD-EASTERN GLACIER-HILL-CASCADE-CHOUTEAU- CENTRAL AND SOUTHERN LEWIS AND CLARK-TOOLE-LIBERTY- EASTERN PONDERA-BLAINE-SOUTHERN ROCKY MOUNTAIN FRONT- EASTERN TETON-JUDITH BASIN-FERGUS-JEFFERSON-BROADWATER-MEAGHER- GALLATIN- 942 PM MST WED DEC 19 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA...NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA. .DAY ONE...THIS AFTERNOON AND TONIGHT THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER TONIGHT IS LOW. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THE POTENTIAL EXISTS FOR COLDER TEMPERATURES AND A CHANCE FOR LIGHT SNOW ACROSS THE REGION SUNDAY THROUGH MONDAY. HOWEVER... CONFIDENCE IN THE TEMPERATURE RANGE AND SNOWFALL AMOUNTS REMAINS LOW AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. MTZ009-201215- NORTHERN ROCKY MOUNTAIN FRONT- 942 PM MST WED DEC 19 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL MONTANA. .DAY ONE...THIS AFTERNOON AND TONIGHT A WINTER STORM WARNING IS IN EFFECT FROM 11 PM THIS EVENING TO 5 PM MST THURSDAY FOR ELEVATIONS ABOVE 5500 FEET. SNOW ACCUMULATIONS OF 6 TO 12 INCHES WITH LOCALLY HEAVIER AMOUNTS AT HIGHER ELEVATIONS ARE EXPECTED. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THE WINTER STORM WARNING CONTINUES INTO THURSDAY EVENING. THE POTENTIAL EXISTS FOR COLDER TEMPERATURES AND A CHANCE FOR LIGHT SNOW ACROSS THE REGION SUNDAY THROUGH MONDAY. HOWEVER... CONFIDENCE IN THE TEMPERATURE RANGE AND SNOWFALL AMOUNTS REMAINS LOW AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
3 high wind. Local standard time, as filed.
High wind gust of 54KT (62MPH) was reported at the Heart Butte, MT RAWS.
High wind gust of 35KT (40MPH) was reported 4 miles NNE of McAllister, MT at the Norris Hill DOT sensor.
High wind gust of 68KT (78MPH) was reported in Cascade, MT.
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, December 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: 426405, 426404, 426406.