Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
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288 FXUS65 KTFX 102151 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 251 PM MST Wed Dec 10 2025 .KEY MESSAGES... - Strong winds continue through this evening along the Continental Divide, and the Madison River Valley and US Hwy 87 corridor through Thursday. - An Arctic front will surge south across the plains on Thursday, bringing falling temperatures and accumulating snow. - Heavier snow remains possible on Friday and into Saturday morning over portions of Central and North Central Montana, but the exact placement of this heavy snow continue to fluctuate. && .DISCUSSION... - Meteorological Overview: An active pattern will continue across the Northern Rockies through the end of the work week thanks to an anomalous moisture streaming eastward from the Pacific Northwest within strong mid-level flow. This strong mid-level flow will continue to bring high winds to portions of the valleys and plains of Central and Southwest Montana, especially those locations near the northern and eastern foothills of terrain and near terrain gaps. Additionally, an Arctic front will surge south and across North Central and portions of Central Montana and undercut the Pacific moisture. Lift associated with this front will help to support a band of snow advancing south during the day on Thursday, with a broader area of snow developing on Friday as a mid-level warm front lifts to the northeast over the Arctic airmass. Above normal temperatures across all locations through Thursday morning will fall to below normal in wake of the Arctic front and remain so through the day on Friday, with the exception of Southwest and portions of Central Montana were above normal temperatures will continue. - Moldan - Forecast Confidence & Scenarios: High Winds through this Evening... The High Wind Warning remains in place for the Northern and Southern High Plains adjacent to the Rocky Mountain Front, Eastern Glacier/Western Toole, and Upper Blackfoot and MacDonald Pass through the early evening hours tonight. Wind gusts across these areas have been gusting anywhere from 55 mph to near 85 mph due to the combination of a strong pressure gradient and/or cross barrier flow and mountain wave activity. It is possible that these warnings may need to be extended into the day on Thursday, most notably for the Northern and Southern High Plains adjacent to the Rocky Mountain Front, given continued mid-level flow of 60-80kts and the presence of a moderately strong pressure gradient; however, with ridgetop stability weakening during the overnight hours and a less favorable environment for mountain wave activity there was enough doubt with this forecast issuance to hold off on extending the High Wind Warning for now. High Winds through Thursday... The High Wind Warnings for Judith Basin County and Judith Gap, and Madison River Valley remain in effect through the afternoon hours on Thursday. High winds will continue across these areas due to the presence of a strong pressure gradient and terrain funneling. Arctic Front and Accumulating Snow on Thursday... Confidence is high in an Arctic front advancing south across the plains of Central and North Central Montana during the morning to early afternoon hours on Thursday. At this time most guidance indicates that the front will initially sag south into portions of North Central Montana by as early as this (Wednesday) evening before briefly retreating north prior to 12z on Thursday. Light snow is likely to accompany this front as it wavers over the plains, especially across northern portions of Hill and Blaine Counties and the Easter Glacier Park Region. A strong surge of pressure rises associated with surface high pressure building south along the Canadian Rockies will then kick the Arctic front back to the south and through Cut Bank and Havre between 12-15z (Thursday) and Great Falls and Lewistown between 15-18z (Thursday). As the Arctic front begins to interact with the terrain of Central Montana it will begin to slow and eventually stall, generally along and north of the US Hwy 12 corridor. A quick 1 to 3" of snow will be possible across most plains locations outside of the Cut Bank Area and I-15 corridor north of Great Falls with the passage of the front, with 2 to 4 inches in the Island Ranges and Rocky Mountain Front. In addition to the threat for accumulating snow, rapidly falling temperatures associated with the front will allow for any wet road surfaces to rapidly freeze. While snowfall amounts are overall on the lighter side, especially given the snowy pattern that we have been in as of late, the threat for a flash freeze was the tipping point to issue a Winter Weather Advisory for any location with 1" or more of forecasted snow. - Moldan Winter Storm Watch Friday and Friday night... The main concern will be how far south the cold front goes and how much lift do we get on the cold side on Friday to create the potential for heavy snow over North Central MT. Where the cold front stalls on Friday will greatly determine where the heavy snow sets up on Friday. Should the front stall a bit further north, the area of heavy snow will likely shift northward a bit into southern Canada. Should the front make it all the way south to I-90, then it is likely that much of North Central MT could get some heavy snow on Friday. Overall, the forecast models continue to show the potential for about a 5 to 12 inch snowfall in the band of heavy snow that sets up on Friday. Additionally, there is the potential for some cold weather advisory statements Friday into Saturday over the northern portions of North Central MT. Brusda && .AVIATION... 10/18Z TAF Period Rain continues across KLWT and KHVR today, with a slight chance for light freezing rain at KHVR through 10/20z since temperatures are still below freezing. Across the region today, a good mid/low level jet is setting up, which will bring speed/directional low level wind shear concerns, especially in the Southwest Valleys. Breezy to gusty southwest/west winds set up across the North- Central MT plains/Madison River Valley today. A front will makes its way south across the Hi-line tonight, which will bring a directional wind shift along with lower clouds and precipitation. KHVR will be most impacted, which a good chance of seeing IFR to LIFR ceilings. This front will continue to push south Thursday morning, but timing uncertainty and with it being right at the end of the TAF period, impacts were left out of the other TAFs this cycle. -Wilson && .PRELIMINARY POINT TEMPS/POPS... GTF 51 52 2 15 / 20 80 70 80 CTB 36 44 -8 9 / 60 60 60 70 HLN 51 52 24 39 / 20 70 80 60 BZN 42 53 40 47 / 10 60 80 50 WYS 32 38 31 39 / 20 40 70 40 DLN 44 52 47 52 / 0 10 20 10 HVR 28 38 -8 4 / 90 80 60 80 LWT 42 49 15 18 / 60 90 90 100 && .TFX WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 8 PM MST this evening for Eastern Glacier, Western Toole, and Central Pondera-Northern High Plains- Southern High Plains-Upper Blackfoot and MacDonald Pass. Winter Weather Advisory from midnight tonight to 3 PM MST Thursday 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 Thursday night 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 to 11 PM MST Thursday 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 Thursday for Judith Basin County and Judith Gap-Madison River Valley. && $$ http://www.weather.gov/greatfalls