textproduct: Great Falls

KEY MESSAGES

- Widely scattered snow showers continue through this evening.

- Widespread strong winds sweep through the region late Wednesday into Thursday, with another period of strong winds over the southwest on Saturday.

- Periods of heavy mountain snow will impact the Continental Divide through Saturday, with cold temperatures and locally heavy lower elevation snow over central and north-centgral MT heading into the weekend.

- Milder and windy conditions look to return next week.

UPDATE

No updates planned for the evening forecast...overall everything is on track. Scattered light snow showers are diminishing this evening, as they continue to move from west to east across the area.

Otherwise, all attention will start to turn towards the strong winds that will develop on Wednesday evening along the Rocky Mountain Front and then spread eastward, over the Plains and across Southwest MT by Thursday morning. Overall, this could be a very strong high wind event. The entire CWA is under a high wind warning...thus no changes.

In terms of snowfall, heavy snow is still expected along the Rocky Mountain Front, beginning on Wed and then going into Sat. Initially, near blizzard conditions are possible Wed night into Thu, and it is still possible that the winter storm warning might be changed to a blizzard warning. Expect colder air to start to move southward on Thu afternoon into North Central MT. This will end the strong winds, but allow for snow to develop over North Central and Central MT. Periods of snow will then continue into Sat. A winter storm watch was issued for a portion of Central MT, with additional winter statements likely issued over the next few days. Brusda

DISCUSSION

/Issued 600 PM MDT Tue Mar 10 2026/

- Meteorological Overview:

Cold westerly flow aloft remains over the Northern Rockies this afternoon with H500 temperatures down to the -35 to -40C range. This combined with surface temperatures in the 30s and 40s will maintain areawide widely scattered snow/graupel showers through this evening. An elevated warm front will bring more scattered rain and snow showers on Wednesday while the westerly flow increases markedly and ushers periods of widespread strong to damaging winds that will peak in strength late Wednesday through Thursday afternoon. During this timeframe there looks to be a wide swath of H700 flow in the 70 to 100 kt range. Both deterministic and ensemble guidance do mix at least some of this to the surface even though the timing of the strongest flow is not quite in phase with peak diurnal mixing. Scattered convective shower activity, associated with elevated instability, will also work to mix stronger winds to the surface.

This set up also brings anomalously Pacific moisture deep into the interior northwest. Snow will continue increasing along the Continental Divide and will become heavy at times for the immediate eastern slopes. The combination of the snow and winds will bring periods of blizzard conditions. Then a Canadian cold front will move southward on Thursday and will decrease the winds for northern areas, but will introduce colder temperatures and snow to much of central and north-central MT Thursday night through Saturday. Snowfall amounts will largely be determined by where the frontogenesis sets up. There's currently some uncertainty on how fast this will move south and whether or not it will stall along the way.

The boundary does looks to move southward and bring another round of strong gusty winds and convective snow showers to southwest MT Saturday afternoon. Models aren't very enthusiastic as far as widespread accumulating snow, but localized snow impacts are definitely on the table, especially over and near the mountain passes. Snow begins to diminish on Sunday, but temperatures look to remain below average for at least one more day. Most ensembles favor ridging aloft to move in next week for milder, but continued breezy to windy conditions. Despite this, there may be one more wave that sneaks in and brings some light, mostly mountain snow on Monday. - RCG

- Forecast Confidence & Scenarios:

Widespread Strong to damaging winds Wednesday night through Thursday...

The combination of anomalously strong winds aloft with scattered convective rain/snow showers look to transfer strong wind gusts generally ranging from 60 to 90 mph over large portions of north- central and southwest Montana for a 2 to 6 hour period, longest over the central plains and along the Rocky Mountain Front. Winds of this magnitude for such a long time span would exert a much larger impact than instantaneous high wind gusts of a typical high wind event. The one confounding factor that could preclude the higher end wind gusts from reaching the surface in such a widespread fashion is the peak upper level winds occurring during the late night and early morning hours, generally between 3 am and noon. There's is an expectation for convective showers to make up for this shortcoming; however, should the showers not be as widespread or effective, then the strongest winds will be far more localized and much shorter in duration. Some impacts may include tree/power line damage, areas of blowing dust or snow, and difficult to dangerous travel for high profile or light weight vehicles. All the high wind watches were upgraded to high wind warnings with the afternoon forecast package.

Periods of heavy mountain snow along the Continental Divide spreading to the lower elevations of central and north-central Montana Thursday night through Saturday... Heavy mountain snow has already commenced over the western mountains west of the Continental Divide. This will only increase as the strong westerly flow aloft ushers in rich Pacific moisture deep into the interior northwest. Areas along the immediate eastern slopes of the divide will see snow totals ranging from 1 to 4 feet through Saturday afternoon. The combination of strong gusty winds will produce near whiteout conditions at times, especially on Thursday. A winter weather advisory has been issued for the Rocky Mountain Front zones and NW Beaverhead County for the near term, with the winter storm watch being upgraded to a winter storm warning for the Rocky Mountain Front zones Wednesday night through Saturday. This will be closely monitored for an upgrade to a blizzard warning should confidence increase with the stronger winds being aligned with the heavy snow.

By Thursday night colder air moves onto the plains, along with an area of H500/H700 frontogenesis. This will bring periods of snow over central and north-central MT Thursday night through Saturday. Currently the heaviest snow looks to fall over the high plains adjacent to the Rocky Mountain Front and then along and north of the central island ranges where snow totals look to generally fall in the 10 to 20 inch range. Lighter amounts in the 3 to 8 inches seem plausible for other central/north-central locations. Ultimately this will depend on precisely where this transient area of frontogenesis sets up. Southwestern areas don't look overly optimistic for accumulating snow aside from locally intense snow showers on Saturday. Winter storm watches have been sent out for most central/north-central locations from Thursday night through Saturday afternoon. - RCG

AVIATION

11/00z TAF Period

Winds and scattered snow showers will wind down early this evening. Snow showers will continue to be a "hit or miss" at terminal through 11/01 - 11/03z. The main concern for Wednesday is diurnal driven breezy to gusty winds picking up again across the region mid to late morning, and continuing throughout Wednesday afternoon. -Wilson

PRELIMINARY POINT TEMPS/POPS

GTF 20 44 37 49 / 20 10 50 70 CTB 16 39 25 40 / 10 10 70 70 HLN 20 46 38 50 / 20 20 50 80 BZN 14 46 35 55 / 20 10 20 60 WYS 5 34 24 45 / 30 10 50 70 DLN 15 44 35 52 / 10 10 30 40 HVR 18 45 28 43 / 10 10 70 80 LWT 16 41 30 46 / 30 20 40 80

TFX WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until 6 PM MDT Wednesday for East Glacier Park Region-Southern Rocky Mountain Front.

Winter Storm Warning from 6 PM Wednesday to 6 PM MDT Saturday for East Glacier Park Region-Southern Rocky Mountain Front.

Winter Storm Watch from Thursday evening through Saturday afternoon for Bears Paw Mountains and Southern Blaine-Cascade County below 5000ft-Eastern Glacier, Western Toole, and Central Pondera-Eastern Pondera and Eastern Teton-Eastern Toole and Liberty-Fergus County below 4500ft-Judith Basin County and Judith Gap-Little Belt and Highwood Mountains-Northern High Plains-Snowy and Judith Mountains-Southern High Plains-Western and Central Chouteau County.

High Wind Warning from midnight Wednesday night to 6 PM MDT Thursday for Beaverhead and Western Madison below 6000ft-Big Belt, Bridger and Castle Mountains-Canyon Ferry Area-Cascade County below 5000ft-Eastern Pondera and Eastern Teton-Eastern Toole and Liberty-Elkhorn and Boulder Mountains-Gallatin Valley- Gallatin and Madison County Mountains and Centennial Mountains- 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-Northwest Beaverhead County-Ruby Mountains and Southern Beaverhead Mountains-Upper Blackfoot and MacDonald Pass-Western and Central Chouteau County.

High Wind Warning from 6 PM Wednesday to 3 PM MDT Thursday for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Northern High Plains-Southern High Plains- Southern Rocky Mountain Front.

High Wind Warning from 3 AM to 6 PM MDT Thursday for Bears Paw Mountains and Southern Blaine-Fergus County below 4500ft-Hill County-Northern Blaine County-Snowy and Judith Mountains.

Winter Weather Advisory from 6 PM Wednesday to noon MDT Friday for Northwest Beaverhead County.