Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
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323 FXUS65 KTFX 111047 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 347 AM MST Thu Dec 11 2025 .KEY MESSAGES... - It turns colder later today as a cold front moves southward through Montana. - A period of heavy snow is possible on Friday, mostly east of a line from Shelby to Belt. - After a brief cool down Friday, it starts to turn warmer Saturday, and by Sunday, many areas over Central and Southwest MT will have afternoon temperatures in the 50s once again. - Several days of windy conditions are expected next week over North Central MT. && .DISCUSSION... - Meteorological Overview: The main concern this morning is the cold front that is forecast to move southward through the CWA. As of 330 AM, the cold air will still up in southern Alberta, near Lethbridge, and not moving southward very fast. This is a concern, as a later arriving cold front might not push as far south as currently forecast. (The Helena/Townsend area...before moving back north.) Thus temperatures from Great Falls southward will be mild today, with some areas already close to 60 degrees. Additionally, the freezing level this morning was over 9000 feet, thus it is going to take some time for the air to cool not only at the surface, but aloft. This could allow for more rain to fall, which could lower snow amounts a bit. In terms of a flash freeze, it is possible, but confidence is lower right now, as the cold air is just gradually moving in over an hour or two, rather than a 15 min period right now. So for today, do expect some light snow, mostly late this morning north of Highway 2 and towards this evening further south. However, snow amounts will be on the light side, generally less than inch at lower elevations...maybe 1 to 3 inches in the mountains. For tonight/Friday, the main concern will be how far south this cold front makes it before it starts to move back northward on Friday. Right now the front is forecast to move down to about a Helena/Townsend line. This might be a bit far south, should the front be slow to arrive. That being said, the cold front is expected to move back northward by Friday afternoon as a warm front. Areas just to the north of this frontal boundary will have the highest chances for heavy snowfall on Friday. Right now, that area is looking to be areas east of a line from Shelby to Belt. Areas over the Plains west of this line will likely just get some minor snow accumulations. East of this line, there is still the potential for about a 5 to 10 inch snowfall at lower elevations and a bit higher amounts in the mountains. Temperatures will be colder over North Central MT, but mild air will continue to reside over Southwest MT. For Saturday and Sunday...expect warmer air to gradually move northward through the CWA, starting in the Central areas on Saturday and then moving through the northern portions of the CWA on Sunday. Any light snowfall from the Friday storm should end early on Saturday. Monday through Thursday...the above normal temperatures will continue through the first half of next week, before slowly cooling a bit late next week. There is a good potential for several days of windy conditions next week, with some periods of strong winds possible over North Central MT. Also, scattered showers will be on the increase, starting as rain early in the week, then going more towards snow by late next week as temperatures cool down a bit. - Forecast Confidence & Scenarios: Snowfall...the location of where the cold front ends up tonight will have significant impacts on where the heavy snow sets up on Friday. The further south the front pushes, the more likely the heavy snow will fall over the eastern portions of North Central MT. If the front stalls out along a line from Great Falls to Lewistown, then just mainly the northern portions of North Central MT will have the potential for heavy snow on Friday. Strong winds early next week...There is already and 80 percent chance that winds could exceed warning criteria along the Rocky Mountain Front and in the Cut Bank area Mon and Tue and a 60 percent chance on Wed. Brusda && .AVIATION... 11/06Z TAF Period An active TAF period is forecast across much of the region. Initial concerns are for gusty surface winds over parts of the plains through the overnight, with the potential for LLWS across areas where surface winds remain/trend light and variable. An initial weaker front ahead of the main Canadian cold front will result in a few wind shifts this evening and overnight across the Hi-Line. Widespread mountain wave turbulence will continue into Thursday. A mix of rain and snow continues across northeastern portions of the region this evening and tonight ahead of a stronger cold front during the day Thursday. This precipitation trends further south through the day, becoming all snow behind the front which moves south across the plains during the morning and early afternoon. Current thinking is that the cold air behind the front will remain over the plains, hence keeping the precipitation type as rain over most valleys in Central and Southwest Montana. Mountains will become increasingly obscured through the TAF period. -AM && .PRELIMINARY POINT TEMPS/POPS... GTF 57 8 16 8 / 70 50 90 60 CTB 51 -1 9 1 / 40 20 80 60 HLN 60 24 40 27 / 80 80 80 30 BZN 56 34 47 33 / 50 70 70 20 WYS 39 30 39 22 / 40 60 50 10 DLN 55 42 53 34 / 20 20 10 0 HVR 39 -3 6 -6 / 70 50 80 90 LWT 49 8 19 5 / 90 70 100 80 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 3 PM MST this afternoon for Bears Paw Mountains and Southern Blaine-East Glacier Park Region-Hill County-Northern Blaine County-Western and Central Chouteau County. Winter Storm Watch from late tonight through late Friday night for Bears Paw Mountains and Southern Blaine-Cascade County below 5000ft-East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Eastern Pondera and Eastern Teton-Eastern Toole and Liberty-Fergus County below 4500ft-Hill County-Judith Basin County and Judith Gap-Little Belt and Highwood Mountains- Northern Blaine County-Northern High Plains-Snowy and Judith Mountains-Southern High Plains-Southern Rocky Mountain Front- Western and Central Chouteau County. Winter Weather Advisory from 9 AM this morning to 11 PM MST this evening for Big Belt, Bridger and Castle Mountains-Cascade County below 5000ft-Fergus County below 4500ft-Gates of the Mountains-Judith Basin County and Judith Gap-Little Belt and Highwood Mountains-Meagher County Valleys-Snowy and Judith Mountains-Southern High Plains-Southern Rocky Mountain Front- Upper Blackfoot and MacDonald Pass. High Wind Warning until 3 PM MST this afternoon for Judith Basin County and Judith Gap-Madison River Valley. && $$ http://www.weather.gov/greatfalls