


Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
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213 FXUS65 KTFX 131521 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 921 AM MDT Mon Oct 13 2025 .KEY MESSAGES... - Snow over central and north-central Montana diminishes later this morning, although lighter snow may persist through Tuesday morning along the divide. - Temperatures slowly warm to near average by the end of the week,but there will be day to day opportunities for scattered shower activity and mostly mountain snow, especially Wednesday through Friday. - Periods of breezy to windy conditions are expected heading into the weekend. && .UPDATE... Morning update has been published, with the main adjustment coming in the form on winter weather highlights. All of the Winter Storm Warnings have been cancelled or downgraded, with the Southern Rocky Mountain Front and Southern High Plains being downgraded to a Winter Weather Advisory which was then subsequently extended until 6PM MDT this evening. Here additional snow accumulations of up to 2 inches are expected thanks to low-level northeast upslope flow, with localized amounts possibly approaching 4 inches. Elsewhere the Winter Storm Warning for the Gates of the Mountains was downgraded to a Winter Weather Advisory as light snow was on- going here; however, no adjustment was made to the endtime as the bulk of the impactful snow is expected to end near noon MDT. Finally the Winter Weather Advisories that were in effect for portions of North Central and Central Montana were cancelled outside of the Upper Blackfoot and MacDonald Pass Area and Cascade County below 5000 ft as additional snowfall accumulations of up to 1" are possible through noon MDT here. Otherwise the only other adjustment to the on-going forecast was to cool temperatures by 2 to 4 degrees as persistent cold air advection and mid- to upper level cloudiness will inhibit any significant solar insolation throughout the day today, especially across Central and North Central Montana where snow has recently fallen over the past 24 hours. - Moldan && .DISCUSSION... /Issued 539 AM MDT Mon Oct 13 2025/ - Meteorological Overview: Cold northeasterly upslope flow will persist over central and north- central MT for much of today while warmer air and moisture overrun the shallow colder air via H500 southwesterly flow. This will maintain cold and damp conditions for the northern half of the forecast area today. Snowfall and wintry impacts will peak this morning before diminishing and retreating to areas along the Rocky Mountain Front later this afternoon into tonight. A closed low diving southward along the Pacific Northwest coast will continue to support difluent flow over the Northern Rockies for the first half the week. Moisture and weak shortwaves moving in from the southwest will bring periods of rain showers and higher mountain snow tonight into Tuesday, mostly for southwest MT. The cold air over central and north-central MT will slowly retreat northward heading into mid- week. The Pacific Northwest closed mid- level low is expected to peak in intensity over central CA before weakening and swinging northeastward through the Great Basin and eventually reaching eastern MT by around Thursday. The evolution of this feature will be complex as it approaches the region, so the precise locations of its low pressure center(s) and resultant precipitation locations is still a bit on the fuzzy side. Overall expect the most widespread rain and mountain snow to occur between Tuesday night and Friday. With milder Pacific air moving in, snow impacts look to be on the minor side and mostly confined to mountain areas. Ridging aloft with stronger westerly flow looks to at least briefly move through the Northern Rockies heading towards the weekend followed by more passing troughs in an increasingly northwesterly flow aloft. This will result in periods of breezy to windy conditions, though the timing details still need to be worked out depending trough and ridge phasing. - RCG - Forecast Confidence & Scenarios: Snow today through Tuesday morning... Warm air aloft overrunning cold northeasterly flow in the low levels continues to bring snow this morning for central and north- central locations along the divide and near the central island ranges. The focus of the heaviest snow initially set up in the Boulder and Helena areas, a little farther south than originally expected. The Helena Airport set a 24 hour snowfall record yesterday with 2.6 inches. The main area of snow has since lifted northward toward the Southern Rocky Mountain Front/central island ranges and their adjacent plains. Although snowfall has generally fallen below expectation for the winter storm warned area, I will leave the warning posted for a bit longer with a general 1 to 4 inches of snow still expected through the morning hours. Slippery roads and power outages from heavy, wet snow will continue to be the primary impacts. Snow gradually diminishes later this morning into the afternoon, though light snow may persist along the Rocky Mountain Front through Tuesday morning. - RCG && .AVIATION... 13/12Z TAF Period Snow over central and north-central MT will slowly retreat to areas along the Rocky Mountain Front as the day progresses; however, MVFR/IFR conditions will generally persist through 14/00Z due to lingering patchy fog and low stratus. There will be some improvement tonight, but there will be lingering MVFR conditions throughout the night. Additionally, while light snow continues along the divide tonight, another shortwave moves into southwest MT and brings more low VFR/MVFR ceilings and mountain obscuration. - RCG && .PRELIMINARY POINT TEMPS/POPS... GTF 33 24 40 28 / 80 20 20 30 CTB 30 23 40 21 / 70 30 10 10 HLN 34 25 41 29 / 90 20 40 50 BZN 41 24 48 30 / 10 10 30 60 WYS 46 23 50 27 / 10 40 60 80 DLN 43 25 48 33 / 10 30 40 50 HVR 39 21 48 29 / 40 10 10 30 LWT 35 23 46 29 / 30 20 20 60 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until noon MDT today for Cascade County below 5000ft-Gates of the Mountains-Upper Blackfoot and MacDonald Pass. Winter Weather Advisory until 6 PM MDT this evening for Southern High Plains-Southern Rocky Mountain Front. && $$ http://www.weather.gov/greatfalls