


Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
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727 FXUS65 KTFX 130932 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 332 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. && .DISCUSSION... - 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... 13/06Z TAF Period Initial concern this TAF period will be for persistent snow and low clouds north of I-90 through the morning. Snow diminishes through the late morning hours into early Monday afternoon, though low clouds look to hang around a bit longer. Mountains will remain obscured north of I-90 through the TAF period. There is a conditional risk for fog at KWYS this morning, dependent on how quickly mid level cloudiness moves away from the terminal. -AM && .PRELIMINARY POINT TEMPS/POPS... GTF 34 24 42 28 / 100 20 20 30 CTB 30 22 41 23 / 70 20 10 10 HLN 37 25 44 30 / 70 20 40 50 BZN 44 24 49 30 / 10 10 30 60 WYS 49 25 51 29 / 0 40 60 80 DLN 46 26 50 32 / 10 30 40 50 HVR 38 24 49 30 / 40 10 10 30 LWT 37 22 48 29 / 50 10 20 60 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until noon MDT today for East Glacier Park Region-Gates of the Mountains-Southern High Plains-Southern Rocky Mountain Front. Winter Weather Advisory until noon MDT today for Cascade County below 5000ft-Eastern Pondera and Eastern Teton-Elkhorn and Boulder Mountains-Helena Valley-Judith Basin County and Judith Gap-Little Belt and Highwood Mountains-Northern High Plains- Upper Blackfoot and MacDonald Pass. && $$ http://www.weather.gov/greatfalls