Although upper level ridging was building in from the west across the Northern Rockies, a strong pressure gradient and a ridgetop inversion supportive of mountain wave activity resulted in strong winds and gusts along the Rocky Mountain Front.
Every event with a place to put it; 2 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.
Although upper level ridging was building in from the west across the Northern Rockies, a strong pressure gradient and a ridgetop inversion supportive of mountain wave activity resulted in strong winds and gusts along the Rocky Mountain Front.
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, 6:19 PM MST, 1 hour 26 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Great Falls MT 619 PM MST Mon Dec 2 2024 Aviation Section Updated. .KEY MESSAGES... - High winds along the Rocky Mountain Front through late Tuesday morning, with the strongest period of winds from this evening through the mid-morning hours on Tuesday. - Above normal temperatures will occur for most locations through Saturday, with the exception of locations northeast of a Cut Bank, to Great Falls, to Lewistown line where temperatures will fluctuate between below normal to near normal from Tuesday through Thursday. - Dry conditions expected through the middle of the work week. - Potential exists for a more widespread wind event from Friday night through Saturday night. && .DISCUSSION... /Issued 150 PM MST Mon Dec 2 2024/ - Meteorological Overview: H500 ridge axis over the western seaboard will gradually shift eastward and towards the Northern Rockies through the middle to end of the work week; however, as the ridge shifts eastward it will see decreasing heights as a series of shortwaves crest the ridge axis and dive southeast over the Northern Rockies and High Plains. The first of these series of shortwaves will move over North Central Montana tonight through Tuesday night, with the main impacts being increasing southwest to west surface winds, especially along the Rocky Mountain Front. The second shortwave will then begin to approach the Northern Rockies on Thursday morning before exiting the region Friday morning. This disturbance will bring another period of strong and gusty winds to portions of the Central and North Central Montana plains and north-south valleys of Southwest Montana, in addition to light precipitation to the Continental Divide. Finally, the third and overall strongest disturbance will begin to approach the Northern Rockies from the Pacific Northwest Saturday morning before moving over the region from Saturday evening through Sunday morning. This disturbance will not only have the best opportunity to produce widespread strong, if not high, winds, but also precipitation mainly in the form of snow, especially in the mountains. - Moldan - Forecast Confidence & Scenarios: High Winds from this afternoon through Tuesday : Confidence remains high in High Winds materializing along the Rocky Mountain Front this afternoon and persisting through Tuesday morning, with the strongest winds occurring between 10 and 30 miles of the Continental Divide north of the MT HWy 200 corridor, especially near the East Glacier Park Area. BUFKIT sounding continue to support a favorable thermal profile near ridgetops with wind speeds of 35-55kts within this stable layer to support mountain wave activity. Additionally, and more importantly in the case of this event, the pressure gradient between Cut Bank and Kalispell will increase from between 6mb to 8mb late this afternoon/early this evening to 10mb by midnight tonight, and then peak at between 10mb to 12mb early Tuesday morning. This strong pressure gradient alone will likely support wind gusts of 50-70 mph along the Rocky Mountain Front and over the adjacent plains, with any mountain wave activity supporting additional speed increases. The High Wind Warning for the Rocky Mountain Front and adjacent foothills and plains, and Eastern Glacier, Western Toole, and Central Pondera Counties will therefore continue, with the only adjustment being to move the start time forward for the East Glacier Park Region and Northern High Plains given the potential earlier onset of High Winds here. - Moldan Temperatures: Milder temperatures are already in place across much of Southwest and Central Montana valleys. This more mild airmass will make inroads on the plains into Tuesday, though will take its time making it across the entirety of the plains. Areas like Havre that are notorious for holding on to the cooler temperatures will once again be slow to warm up this week. After a brief cooldown across the plains Wednesday an even milder airmass makes another push into the region Thursday into Saturday. This weekend: Cluster guidance still favors ridging in some capacity this weekend, though there are an increasing number of members that are favoring at least a partial breakdown of the ridge. Scenarios that favor this breakdown would result in a period of gusty winds and would increase chances for precipitation across the region. The chance for a 58 mph gust around Cut Bank Saturday is around 75%, increasing to around 85% in Browning. -AM && .AVIATION... 03/00Z TAF Period The main concern for this period will be winds over North Central and Central Montana. Strong northwest winds aloft will continue mountain wave turbulence with periods of low-level wind shear. Surface winds will be strongest along the Rocky Mountain Front and adjacent plains, where gusts are forecast to exceed 45 kt at times, with gusts in excess of 60 kt possible closer to the Rocky Mountain Front. Winds will start to decrease after 15Z. Overall, though, VFR conditions are forecast to continue across North Central, Central, and Southwest Montana through at least 04/00Z. Mainly high-level cloudiness will pass over the area for much of the period, but mid-level cloudiness will start to increase over the plains after 15Z. Patchy fog is possible north and east of KHVR and in some Southwest MT valleys, but the probability that fog will directly impact any of the terminals is low. -Coulston Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 32 46 23 41 / 0 0 0 0 CTB 27 42 19 33 / 0 0 0 0 HLN 24 48 23 47 / 0 0 0 0 BZN 19 47 20 46 / 0 0 0 0 WYS 6 38 6 39 / 0 0 0 0 DLN 23 48 19 46 / 0 0 0 0 HVR 7 35 16 27 / 0 0 10 10 LWT 28 47 25 43 / 0 0 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 11 AM MST Tuesday for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera- Northern High Plains-Southern High Plains-Southern Rocky Mountain Front. && http://www.weather.gov/greatfalls
The national radar mosaic for the moment the first event began.
2 high wind. Local standard time, as filed.
Montana Mesonet station Dog Gun Lake E (acedoggu) measured a 68 mph gust. Additionally, mesonet station MTBWG Browning (MT DOT) measured multiple 58 mph gusts.
Montana mesonet station Mission Lake S (acemissi) measured sustained winds, averaged over an hour, of 41 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2024Every state in 2024This day in weather historyWarnings in Montana, December 2024
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: 1219410, 1219409.