Strong zonal flow ahead of an initial shortwave during the afternoon of the 15th was translated to the surface through early on the 16th. These winds were stronger and more widespread than the previous event a day prior, but paled in comparison to the winds that developed just a day or so later on the 17th.
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 TFX wrote it up.
Strong zonal flow ahead of an initial shortwave during the afternoon of the 15th was translated to the surface through early on the 16th. These winds were stronger and more widespread than the previous event a day prior, but paled in comparison to the winds that developed just a day or so later on the 17th.
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 15, 4:54 AM MST, 1 hour 6 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Great Falls MT 454 AM MST Mon Dec 15 2025 .KEY MESSAGES... - Mild temperatures continue early this week with multiple high wind episodes expected through the upcoming week. - Strong winds develop today across north-central Montana with wind speeds peaking along the Rocky Mountain Front this afternoon and late this afternoon through tonight further east. - A strong cold front on Wednesday will bring another period of widespread and potentially damaging winds to much of the area as well as the potential for locally intense snow showers. && .DISCUSSION... - Meteorological Overview: Flat upper level ridging exists across the western US downstream of troughing in the NE Pacific with fast mid-upper level westerly flow across the Northern Rockies and MT. A pair of shortwave disturbances ejecting out of the offshore trough will progressively flatten the ridge through Wednesday with significant wind events expected with the passage of each wave, particularly on Wednesday with the most widespread/impactful winds. Temperatures remain well above average today with a few locations potentially reaching daily records again. It's worth mentioning that Dillon is now up to a 5 day stretch of daily record maximum temps with another possible today. Main story however will be the development of strong winds today as mid-level flow increases ahead of the initial shortwave disturbance moving onshore with surface low pressure emerging in central AB late this afternoon and tracking east while the shortwave translates east along the US/Canadian border tonight. As mid-level flow increases today strong winds will redevelop along the Rocky Mountain Front before spreading east across much of north-central MT tonight. There is a period of somewhat decreased winds on Tuesday before the second and stronger wave approaches the area Tuesday night. 700MB wind speeds increased to 65-85kts as this wave moves across the area Wednesday, supporting the potential for widespread strong winds. Meanwhile, Pacific moisture emebedded in the flow will initially bring precipitation to areas along the continental divide near GNP today and tomorrow with snow levels remaining relatively high. Additional moisture arrives with a Pacific cold front on Wednesday along with lowering snow levels through significant snowfall is mainly limited to areas along the continental divide north of Rogers Pass to the Canadian border. Rain and snow showers spread east with the cold front on Wednesday with cooling aloft providing enough instability for locally intense showers. Hoenisch - Forecast Confidence & Scenarios: Very favorable conditions for mountain wave wind enhancement are expected this afternoon along the Rocky Mtn Front, including a stable/critical temp/wind profile above mountain tops, which will support the potential for gust in excess of 85 mph there and possibly a few isolated gusts to around 100 mph in the most terrain favored locations on the east slopes. As this initial wind maximum translates east this evening/overnight, stronger gusts spread across north-central MT with enough lingering mountain wave support for the risk of isolated gusts in excess of 65-75 mph across areas downstream of the Little Belts including Judith Basin county. Cooling aloft on Wednesday will allow for effective atmospheric mixing across the entire area which will also aid in Wednesday's strong winds being more widespread and of longer duration (multiple hours of very windy conditions vs the typical 1-3 hr peak period). This and the notably significant 850-700MB wind speeds (>90th climatological percentile) has the potential to produce a more impactful and widespread than average wind event for the area, including in the Helena and Gallatin valleys. Hoenisch && .AVIATION... 15/12Z TAF Period VFR conditions prevail through the TAF period. Mountain wave turbulence and instances of low level wind shear will increase later today and tonight as westerly flow aloft strengthens with gusty winds impacting most north-central MT terminals this afternoon through tonight. Hoenisch && .HYDROLOGY... Mild daytime and overnight temperatures will lead to rapid melting of the recent snow across eastern portions of north-central MT. With initially frozen ground, much of the snowmelt is likely to remain on the surface and may lead to standing water. While overall impact to creek/stream levels is low, most creeks are likely to be frozen with potential for water flow over the ice or potentially back up in some creek bottoms. Hoenisch && .PRELIMINARY POINT TEMPS/POPS... GTF 60 41 52 41 / 10 0 10 20 CTB 55 34 45 33 / 10 10 10 40 HLN 51 37 52 35 / 10 20 20 40 BZN 54 37 55 36 / 10 10 10 10 WYS 39 24 40 31 / 10 20 30 50 DLN 54 37 54 35 / 10 10 10 20 HVR 44 30 44 30 / 20 0 10 30 LWT 51 34 46 34 / 10 0 10 10 && .TFX WATCHES/WARNINGS/ADVISORIES... High Wind Watch from Tuesday evening through Wednesday evening for Bears Paw Mountains and Southern Blaine-Big Belt, Bridger and Castle Mountains-Canyon Ferry Area-Cascade County below 5000ft-East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Eastern Pondera and Eastern Teton-Eastern Toole and Liberty-Elkhorn and Boulder Mountains-Fergus County below 4500ft-Gallatin Valley-Gates of the Mountains-Helena Valley-Judith Basin County and Judith Gap-Little Belt and Highwood Mountains-Madison River Valley-Meagher County Valleys- Missouri Headwaters-Northern High Plains-Snowy and Judith Mountains-Southern High Plains-Southern Rocky Mountain Front- Upper Blackfoot and MacDonald Pass-Western and Central Chouteau County. Winter Storm Watch from Tuesday evening through Wednesday evening for East Glacier Park Region-Southern Rocky Mountain Front. High Wind Warning from noon today to 11 AM MST Tuesday for Bears Paw Mountains and Southern Blaine-Cascade County below 5000ft- Eastern Pondera and Eastern Teton-Fergus County below 4500ft- Hill County-Judith Basin County and Judith Gap-Little Belt and Highwood Mountains-Northern Blaine County-Snowy and Judith Mountains-Upper Blackfoot and MacDonald Pass-Western and Central Chouteau County. High Wind Warning until 8 AM MST Tuesday for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera- Eastern Toole and Liberty-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.
17 high wind. Local standard time, as filed.
An ambient weather station, RAWS station SRYM8 Saint Mary RAWS, and mesonet station SNPMT Sunpoint in Glacier NP measured gusts in excess of 60 mph, including a peak gust of 67 mph at the Ambient station in Babb.
Numerous sensors in northern Liberty measured strong winds and gusts, including GW0718 Joplin 25 NNW and MT mesonet station Mt Lebanon SE to name a couple. The peak observed gusts was 82 mph at Joplin 25 NNW.
Mesonet stations MTM51 Gildford and MTM06 N Havre both measured gusts of 58 mph or greater, including a peak gust of 60 mph at Gildford.
Multiple sensors in this zone, including MTBRN Two Medicine Bridge, MT Mesonet stations Dog Gun Lake E, Wetzel NE, and Dupuyer N, and MTBWG Browning DOT measured gusts in excess of 75 mph or sustained winds averaging 50 mph or greater over at least an hour. The peak observed gust was 94 mph at the Browning DOT sensor.
Numerous sensors in this zone reported sustained winds of 40 mph or greater observed over at least an hour or gusts to 58 mph or greater, including MT mesonet stations Mission Lake S, Buffalo Lake E, Sunburst NNW, Conrad N, Ledger N MDA, and Ethridge N, MT DOT sensors Sunburst (MTSUN), Sweet Grass (MTSWT), and Valier Jct (MTVAR), and ASOS/AWOS stations KCTB Cut Bank and KSBX Shelby. There were more sensors than this, but you get the point. Peak observed gust in this zone was 84 mph at Mission Lake S.
A personal weather station at Upper Elk Creek, RAWS station GSNM8 Gleason, and MT DOT sensor MTROG Rogers Pass measured gusts in excess of 60 mph, including a peak gust of 82 mph at Upper Elk Creek.
Many sensors in this zone measured sustained winds of 50 mph or greater over at least an hour or gusts in excess of 75 mph, including sensors MTCTS Choteau South, DELMT Dellwo, MTPND Pendroy, and Bynum W MT mesonet. The peak observed gust at a sensor was 88 mph at Dellwo along the immediate eastern slopes of the Rockies.
Mesonet station MTNOR Norris Hill measured several instances of high sustained winds, in addition to a few gusts in excess of 58 mph. The peak gust at this sensor was 61 mph.
Mesonet station MTGYS Geyser, AWOS station K1CM Charlie, and MT mesonet stations Judith Gap, Moccasin, and Benchland all measured gusts of 58 mph or greater. The peak gust was at Geyser, and was 67 mph.
ASOS station KGTF Great Falls Airport, AWOS station K1AM Raynesford, MTM76 Cascade E MDA, and MT mesonet stations Eden NW and Sun River SE all measured gusts of 58 mph or greater, with Sun River SE measuring sustained winds of 40 mph or greater over at least an hour. The peak observed gust was 64 mph at Sun River SE.
MT mesonet stations Carter N, Highwood Bench, Frenchmans Ridge, Fort Benton E, and MTM02 S Loma, along with mesonet station MTLOM Loma DOT all measured gusts in excess of 58 mph, including a few reports of sustained winds of 40 mph averaged over an hour. The peak observed gust was 61 mph at several sensors.
A combination of mesonet sensors (Forestgrove N and MTBCH Beacon Hill) and AWOS sensors (KMVH N Bar Ranch, K1OM Oscar, and K1NM November) all measured gusts of 58 mph or greater. The peak observed gust was 75 mph at Beacon Hill.
Mesonet stations MTCHK Chinook and MTM48 Chinook E MDA both measured gusts in excess of 58 mph, in addition to MTCHK measuring sustained winds averaging 40 mph over an hour. The peak observed gust was 63 mph at Chinook E MDA.
MT mesonet station Cleveland N and RAWS station FBLM8 Fort Belknap both measured gusts in excess of 58 mph, in addition to Cleveland N measuring sustained winds averaging at least 40 mph over an hour. The peak observed gust was at Cleveland N and was 71 mph. There was also a report received of a tin roof being ripped off a shed and thrown between 150 and 200 feet downwind.
Mesonet station MTM73 Ledger N MDA measured two gusts of 58 mph or greater, including a peak gust of 63 mph.
Mesonet station Mtfps Flesher Pass MTDOT measured a 59 mph gust.
Mesonet station MTMON Monarch Canyon and RAWS station SFJM8 South Fork Judith measured gusts in excess of 58 mph, including a peak gust of 63 mph at Monarch Canyon.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2025Every state in 2025This day in weather historyWarnings in Montana, December 2025
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: 1303311, 1303319, 1303314, 1303312, 1303313, 1303316, 1303317, 1303320, 1303315, 1303307, 1303309, 1303310, 1303305, 1303306, 1303321, 1303318, 1303308.