textproduct: Great Falls

KEY MESSAGES

- A long duration and significant wind event will impact the Northern Rockies through the evening hours today.

- Blizzard conditions will continue along the Rocky Mountain Front through the early afternoon today, with winds gradually decreasing thereafter; however, snow will continue into the first half of the weekend.

- Winter weather impacts increase across north-central and central Montana tonight through Saturday as areas of snow become more widespread.

UPDATE

/Issued 529 AM MDT Thu Mar 12 2026/

Morning update has been published, with the main change being to update diurnal to better match observed temperatures and relative humidity values overnight. Otherwise the remainder of the forecast remains on track, with winds gusts of between 60-80 mph being observed along the Montana Hwy 200/US Hwy 87 corridor from between Great Falls and Stanford and along, immediate Rocky Mountain, and across portions of Southwest Montana. As the morning progresses these strong winds will continue to overspread the remainder of Southwest, Central, and North Central Montana. Travel will be very dangerous for high profile vehicles through the morning and into the afternoon hours. Power outages are likely to occur given the duration of the winds and stress to infrastructure, especially in areas that do not typically see these winds. If you must venture outside be aware of your surrounding. Watch out for flying debris and downed power lines. - Moldan

DISCUSSION

/Issued 529 AM MDT Thu Mar 12 2026/

- Meteorological Overview:

A plume of Pacific moisture within strong westerly flow aloft will stream eastward and across the Northern Rockies through Saturday, with the initial plume through Thursday being orientated along the entirety of the Continental Divide from the Idaho border to the Canadian border before shifting south to mainly affect the southern 2/3rd of the Divide for the remainder of the period. This plume of moisture will help to support a multi-day snowfall event along the Continental Divide into the first half of the upcoming weekend, with most mountain locations measuring storm total snowfall in the feet. At the surface an area of low pressure will emerge across Southern Alberta during the early morning hours on Thursday and quickly move east over Western NoDak by Thursday afternoon. As this surface low moves east a cold front will begin to dive south and east over the plains of North Central and Central Montana during the afternoon and evening hours on Thursday. This front and where it ultimately stalls across Central Montana will not only be the focus for lower elevation snowfall during the days on Friday and Saturday, but will also serve the purpose of shutting down the strong westerly winds on Thursday. Strong to very strong westerly winds will be experienced across the entirety of Southwest through North Central Montana from the early morning hours on Thursday through Thursday evening, with winds gradually subsiding from north to south. Additional opportunities for strong winds will arrive across Southwest Montana, mainly south of the I-19 corridor, on Friday and Saturday as continued strong westerly winds aloft move over the area. - Moldan

As the upper-level wave exits the region, a ridge builds into the Western U.S. next week. Being along the eastern edge of the ridge will bring a northwest flow aloft pattern for the beginning of next week before the ridge flattens out mid week. Overall, the forecast period will be drier, but a few disturbances rounding out the ridge will bring a few chances for precipitation through mid week. Strong 700mb flow looks to keep windy conditions next week. The ridge combined with strong winds will bring well above average temperatures by midweek. -Wilson

- Forecast Confidence & Scenarios:

High Wind Hazards for Thursday :

Confidence in a widespread, long duration, and significant wind event remains high across all of North Central, Central, and Southwest Montana. Latest deterministic and ensemble guidance has slowed down with the arrival of a southward advancing cold front, which would help to shut-off the strongest winds, until later in the afternoon across portions of North Central Montana. This slower southward movement of the front may require a temporal extension of the High Wind Warning for portions of Glacier, Pondera, and Teton counties given the current 21z expiration. Otherwise the remaining High Wind Warnings remain on track. This event will stress infrastructure across the area, with ~7 to 14 hours of continuous sustained wind speeds of 40-50 mph and/or gusts in excess of 60 mph. - Moldan

Winter Weather Hazards:

Blizzard conditions will continue near the continental divide from Glacier NP to as far south as Rogers Pass as higher intensity snowfall rates and stronger winds continue. Further south along the divide, snowfall amounts decrease, but periods of more intense snow and winds could create localized periods of blowing snow with visibility 1/2 mile or less from MacDonald Pass south through NW Beaverhead county.

Areas adjacent to the East Glacier Region and Rocky Mtn front may see some minor snow accumulations as snow showers move off the continental divide following the Pacific front Thursday morning. The combination of very strong winds (gusts in excess of 70mph), some fresh snowfall and downstream wind transport of snow from areas to the west, could also produce reduced visibility in blowing snow, though not to the extent as areas further west. - Hoenisch

The Winter Storm Watch for portions of the Central and North Central Montana plains and Island Ranges has been upgraded to either a Winter Storm Warning or Winter Weather Advisory from this evening through Saturday afternoon; with the focus for the heaviest snow and subsequent impacts expected along and south of the MT Hwy 200 corridor, especially between Great Falls and Lewistown, and west of the US Hwy 89 corridor from Great Falls to Browning. North and east of this line snowfall amounts begin to drop off and with this being a multi-day snowfall event the expected impacts are likely to be that of the nuisance variety. South of the Little Belt and Snowy Mountains a Winter Storm Watch has been issued to include the Big Belt, Bridger and Castle Mountains, Elkhorn and Boulder Mountains, Helena Valley, and Meagher County Valleys due to uncertainty on how far south the cold front and associated snow band moves. Finally the Winter Storm Warning for the Upper Blackfoot and MacDonald Pass, which currently runs through noon Friday, may need to be extended further into the day on Saturday but uncertainty remains once again in how far south the persistent snow will be over this time. - Moldan

AVIATION

12/18z TAF Period

Initial concern this TAF period will be for continued gusty winds in most areas through the remainder of the afternoon, decreasing from northwest to southeast late afternoon and early evening. A mix of rain and snow showers streaming across the Continental Divide will persist through the afternoon before a more stratiform type of precipitation becomes dominant this evening. A few instances of lightning cannot be ruled out in the showery activity this afternoon.

At least light intermittent snow will develop this evening over the plains, with highest confidence in impacts in Lewistown overnight. Mountains will be obscured through the TAF period. -AM

PRELIMINARY POINT TEMPS/POPS

GTF 47 26 29 21 / 40 70 90 80 CTB 39 19 27 14 / 30 70 80 70 HLN 47 30 39 27 / 90 90 100 90 BZN 53 32 49 31 / 30 50 60 80 WYS 45 31 44 31 / 40 50 80 70 DLN 52 36 54 36 / 30 20 30 50 HVR 45 20 33 16 / 50 50 40 60 LWT 45 22 31 18 / 70 100 100 100

TFX WATCHES/WARNINGS/ADVISORIES

Blizzard Warning until 3 PM MDT this afternoon for East Glacier Park Region-Southern Rocky Mountain Front.

High Wind Warning until 6 PM MDT this evening for Bears Paw Mountains and Southern Blaine-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- Fergus County below 4500ft-Gallatin Valley-Gallatin and Madison County Mountains and Centennial Mountains-Gates of the Mountains- Helena Valley-Hill County-Judith Basin County and Judith Gap- Little Belt and Highwood Mountains-Madison River Valley-Meagher County Valleys-Missouri Headwaters-Northern Blaine County- Northwest Beaverhead County-Ruby Mountains and Southern Beaverhead Mountains-Snowy and Judith Mountains-Upper Blackfoot and MacDonald Pass-Western and Central Chouteau County.

Winter Weather Advisory until 3 PM MDT this afternoon for Northern High Plains-Southern High Plains.

Winter Weather Advisory from 6 PM this evening to 6 PM MDT Saturday for Bears Paw Mountains and Southern Blaine-Eastern Glacier, Western Toole, and Central Pondera-Eastern Toole and Liberty-Western and Central Chouteau County.

Winter Storm Warning from 3 PM this afternoon to 6 PM MDT Saturday for East Glacier Park Region-Southern Rocky Mountain Front.

Winter Storm Warning until 6 PM MDT Saturday for Little Belt and Highwood Mountains-Snowy and Judith Mountains.

Winter Storm Watch from 6 PM MDT this evening through Saturday afternoon for Big Belt, Bridger and Castle Mountains-Elkhorn and Boulder Mountains-Helena Valley-Meagher County Valleys.

High Wind Warning until 3 PM MDT this afternoon for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera- Northern High Plains-Southern High Plains-Southern Rocky Mountain Front.

Winter Storm Warning from 6 PM this evening to 6 PM MDT Saturday for Cascade County below 5000ft-Eastern Pondera and Eastern Teton-Fergus County below 4500ft-Gates of the Mountains-Judith Basin County and Judith Gap-Northern High Plains-Southern High Plains.

Winter Storm Warning until noon MDT Friday for Northwest Beaverhead County-Upper Blackfoot and MacDonald Pass.