A series of rather potent shortwaves and associated zonal flow resulted in a period of stronger winds across the plains of North-central Montana early in December. Short breaks were observed between periods of higher winds, resulting in several rounds of High Wind Warnings.
Every event with a place to put it; 8 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 TFX wrote it up.
A series of rather potent shortwaves and associated zonal flow resulted in a period of stronger winds across the plains of North-central Montana early in December. Short breaks were observed between periods of higher winds, resulting in several rounds of High Wind Warnings.
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 2, 8:37 PM MST, 1 hour 6 minutes earlier.
Area Forecast Discussion National Weather Service Great Falls MT 837 PM MST Sat Dec 2 2023 .SYNOPSIS... Periods of strong winds and primarily mountain snow are expected with the passage of two PAcific weather systems this weekend with the first system moving through the region this evening. After a brief lull early Sunday, the system moves across the area late Sunday afternoon through early Monday. Much above average temperatures are then expected Tuesday and Wednesday as a ridge of high pressure builds in. && .UPDATE... The evening update has been published. Gusty winds and scattered, mostly mountain, snow showers following the passage of a Pacific cold front will gradually diminish heading into the overnight hours. Most of the impacts in terms of slippery/snow covered roads and reduced visibility have been in the Homestake Pass area and west/northwest Beaverhead County. The Winter Weather Advisories for the Rocky Mountain Front zones were extended to midnight due to ongoing snow showers and gusty winds there. These advisories as well as the one for the Chief Joseph/Big Hole Pass area look like they will be allowed to expire at midnight. I considered adding the Homestake Pass area to the advisory, but held off since these impacts should be short lived. Winds have been gusty at times, but have largely fell short of warning criteria; however, there is still some opportunity for gusts to become strong, so the two High Wind Warnings left (MacDonald Pass area/Judith Basin County) were left as is. Pops were adjusted per current trends and winds were lowered at bit for the overnight hours. The remainder of the forecast remains in good shape. - RCG && .AVIATION... 448 PM MST Sat Dec 2 2023 (03/00Z TAF Period) A fast moving Pacific shortwave and attendant cold front will continue to move the region this evening into tonight. Strong west to northwesterly flow aloft will maintain gusty winds, mountain wave activity, and instances of low level wind shear through 03/09Z before decreasing in a west to east fashion. Snow shower activity will be mostly confined to the mountains, but KHLN, KEKS, and KBZN may see brief a brief period of snow showers along with low VFR/MVFR conditions through 03/06Z. After a brief of lighter winds on Sunday, the next shortwave approaches Sunday afternoon and evening and delivers another round of strong, gusty winds and mostly mountain snow showers. - RCG Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PREV DISCUSSION... /ISSUED 127 PM MST Sat Dec 2 2023/ Periods of strong winds and mainly mountian snow will impact the area through early Monday as a series of fairly vigorous shortwave troughs move across the region. Satellite imagery this afternoon shows the initial mid level wave beginning to dampen as it reaches the northern Rockies while next system upstream still appears fairly potent as it tracks across the Gulf of AK. Snow was developing across western MT this afternoon ahead of the incoming front associated with the initial system with a period of accumulating snow expected near the continental divide from Rogers Pass north to the Canadian border through early this evening. A less organized area snow showers will accompany the front east across north-central and southwest MT this evening. Snow accumulations of 1- 4 inches are still expected along the continental divide north of Rogers Pass this afternoon with the Marias Pass area the most likely travel corridor to be affected and a winter weather, advisory remains in effect through 6pm. Further south and east, some more organized snow showers could bring localized accumulations to around 2 inches near the ID and WY borders. Strong winds are primarily a concern for portions of north-central MT through tonight but gusty winds will be widespread across all areas, peaking with the frontal passage this evening. A High Wind warning remains in effect for areas along and to the lee of the Rocky Mtn Front and across the Judith Basin area where terrain/wind interaction is most likely to produce some gusts in excess of 50kts. A brief period of low-amplitude ridging translates east across the area late tonight through early Sunday allowing for a relatively dry period with winds relaxing some before the next period of strong wind develops late Sunday through Monday morning in association with the system currently moving through the Gulf of AK. Mid level winds are stronger with this system as it crashes the weak ridge over the region, which also creates a more favorable (stable) temperature profile for mountain wave enhancement at the onset Sunday night. Model ensembles have a 60% or greater probability for strong winds (> 50Kt gusts) west of I-15 from northern Lewis and Clark county north to the Canadian border as well as areas adjacent to the N/E slopes of the Little Belt, Highwood and Bears Paw mountains where the High Wind Warning continues. Precipitation looks to again be focused near the continental divide with some minor snow accumulation possible at some passes initially Sunday night before snow levels rise Sunday night through Monday with warming aloft. Upper level ridging amplifies Monday into Tuesday with additional warming pushing temperatures well above seasonal averages with some areas potentially seeing daytime maximum temperatures around 60 Tuesday. While strong winds look to peak Sunday night, windy conditions are likely to continue through at least Tuesday on the plains as disturbances passing over the ridge enhance the surface trough to the lee of the Rockies at times. A plume of moisture with sub-tropical origins also continues to move over the ridge early next week, keeping cloud-cover plentiful and overnight lows on the mild side, while also keeping humidity on the higher side despite the westerly flow. Longer range model ensembles are in very good agreement in the depiction of large scale upper level ridging centered across the area Tuesday progressing east as the next upper trough from the Pacific moves onshore and into the western US by the end of the week. Cluster analysis reveals some differences in timing/and amplitude of the trough late next week with about 2/3 of model ensemble members supporting a more amplified trough than the mean. && .PRELIMINARY POINT TEMPS/POPS... GTF 26 45 37 52 / 10 10 10 20 CTB 24 43 33 47 / 10 10 10 10 HLN 24 44 33 51 / 60 20 20 30 BZN 17 39 29 50 / 60 10 20 30 WYS 7 27 21 35 / 100 80 80 60 DLN 17 37 27 47 / 50 20 10 10 HVR 24 43 30 48 / 60 10 10 10 LWT 24 42 30 47 / 30 0 20 20 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until midnight MST tonight for East Glacier Park Region-Northwest Beaverhead County-Southern Rocky Mountain Front. High Wind Warning from 2 PM Sunday to 11 AM MST Monday for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Northern High Plains-Southern High Plains-Southern Rocky Mountain Front. High Wind Watch from Sunday afternoon through Monday morning for Bears Paw Mountains and Southern Blaine-Cascade County below 5000ft-Eastern Pondera and Eastern Teton-Eastern Toole and Liberty-Fergus County below 4500ft-Gates of the Mountains-Snowy and Judith Mountains-Upper Blackfoot and MacDonald Pass-Western and Central Chouteau County. High Wind Warning until midnight MST tonight for Upper Blackfoot and MacDonald Pass. High Wind Warning until 4 AM MST Sunday for Judith Basin County and Judith Gap. High Wind Warning from 5 PM Sunday to 11 AM MST Monday for Judith Basin County and Judith Gap. && http://www.weather.gov/greatfalls
Special Weather Statement National Weather Service Great Falls MT 543 PM MST Sat Dec 2 2023 MTZ320-322>330-030330- Big Belt, Bridger and Castle Mountains- Elkhorn and Boulder Mountains-Canyon Ferry Area- Missouri Headwaters-Madison River Valley-Gallatin Valley- Northwest Beaverhead County- Beaverhead and Western Madison below 6000ft- Ruby Mountains and Southern Beaverhead Mountains- Gallatin and Madison County Mountains and Centennial Mountains- Including the cities of Trident, Maudlow, Battle Ridge Pass, Bozeman Pass, Deep Creek Pass, Montana City, Clancy, Boulder, Corbin, Wickes, Elk Park Pass, Homestake Pass, Toston, Townsend, Winston, Harrison, Three Forks, Willow Creek, Pony, Whitehall, Cameron, Ennis, Jeffers, McAllister, Norris, Bozeman, Gallatin Gateway, Dewey, Wisdom, Wise River, Big Hole Pass, Chief Joseph Pass, Bannack, Dillon, Glen, Waterloo, Monida Pass, Big Sky, West Yellowstone, Targhee Pass, and Raynolds Pass 543 PM MST Sat Dec 2 2023 ...Scattered snow showers and gusty winds will continue moving through Southwest Montana through the evening hours... Scattered snow showers and gusty westerly winds in excess of 40 mph at times will impact Southwest Montana for the remainder of the evening. Total snow accumulations up to 3 inches will be possible at pass level, particularly over Big Hole and Chief Joseph Pass. Impacts will include slippery roads and reduced visibility down to a mile or less with the heavier snow showers. Snow impacts will mostly be over the mountain passes, but lower elevations may see brief periods of reduced visibility and minor snow accumulations as well. Anyone traveling this evening should be prepared for potential rapid changes to wintry driving conditions over short distances.
The national radar mosaic for the moment the first event began.
8 high wind. Local standard time, as filed.
Mesonet sensor MTSBN Sieben Flats measured a single gust of 60 mph.
Mesonet station MTBRN Two Medicine Bridge (MT DOT) measured a lone gust to 71 mph.
Ambient Weather Equipment measured a gust of 64 mph at LJ Johnson farm in northeastern Glacier County.
Mesonet station DELMT Dellwo (MCSCN) measured two wind gusts in excess of 60 mph, including a peak gust of 72 mph.
Mesonet station LGPVC Logan Pass Visitor Center measured a gust of 71 mph.
RAWS station JPKM8 Judith Peak measured a lone gust to 59 mph.
RAWS station HRKM8 Harkness measured a lone gust to 60 mph.
ASOS station KCTB Cut Bank measured two gusts of 58 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2023Every state in 2023This day in weather historyWarnings in Montana, December 2023
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: 1144748, 1144780, 1144784, 1144789, 1144764, 1144756, 1144754, 1144796.