Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
737 FXUS65 KTFX 081509 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 809 AM MST Mon Dec 8 2025 .KEY MESSAGES... - Strong winds develop later today and then continue into Tuesday. - Mild temperatures expected at lower elevations the next few days. - Daily mountain snowfall will continue, but snow levels will be rather high early this week. - Still looking to get rather cold for a few days late this week, but warms back up over the weekend. && .UPDATE... Satellite imagery this morning shows an extensive Chinook Arch developing across the area on the nose of fairly extensive upper level jet and Pacific moisture plume moving into the Northern Rockies. Main weather impact today will be the increasing winds with strongest winds still expected to become more widespread tonight through early Tuesday. Snow develops along the continental divide through this afternoon with snow levels currently around 4500 ft, expected to rise to around 6500 ft by this evening as milder flow from the Pacific continues to overspread the area. Temperatures this morning are already in the upper 30s to around 40 across most of the plains/valleys with afternoon temps on track to reach the upper 40s to around 50 at many lower elevation locations, with warmest temps in areas adjacent to the east slopes of the Rockies and just north of the Little Belts. Hoenisch && .DISCUSSION... /Issued 437 AM MST Mon Dec 8 2025/ - Meteorological Overview: A strong westerly flow aloft will reside over the CWA through early Tuesday. This will result in periods of strong winds at the surface later today and into Tuesday. A few isolated strong wind gusts occurred overnight, but I expect the stronger wind gusts to start to become more widespread this afternoon and evening. The brisk westerly flow is also allowing for mild temperatures to move into the CWA. Just a few locations along the Milk River in Blaine County and a few locations along the Missouri River breaks area in Fergus County have not warmed up yet. Overall, I went with near NBM temperatures, but I did raise them in a few locations a few degrees. Note, the GFS model is even warmer, especially on Wed. A concern for Tue is the GFS model as the cold air moving back down from Canada for a few hours as the area of low pressure that causes all the wind moves off to our east. The NAM model is not as aggressive with the cold air. However, the GFS solution could have some more impacts if it pans out, such as colder air moving back in, and some convective snow showers along the frontal boundary. Otherwise, warmer air returns for Wednesday, before most models agree that the cold air makes a return Wed night into Thu. Expect a sharp drop in temperatures behind this cold front. Precip -> Today through Wed -> Snow levels will be rather high through this period, unless the GFS pans out for Tue afternoon, lowering snow levels for a few hours. This will result in rain falling for elevations generally below 5500 feet most days. (The freezing level at Midnight was 7000 feet.) Thus no winter weather advisories will be issued at this time for early this week. (That could change if the GFS pans out for Tue though.) Thursday through Friday...Overall the forecast models agree it will turn colder/snowy for a few days. The GFS model continues to be the most aggressive with the snowfall. Overall the NBM is a good solution at this time, with snowfall amounts of 3 to 6 inches at lower elevations over North Central MT and well over a foot in the mountains. In Southwest MT, the snowfall will not be as much, as the forecast models generally stall the cold front out along a line from just south of Helena to just north of Bozeman. Temperatures near the US/Canadian border will be quite cold on Friday and cold weather advisory criteria might be met. Saturday through Monday...expect a gradual warming trend, with some light precipitation, mostly over the mountains of the Rocky Mountain Front. - Forecast Confidence & Scenarios: There is an 80 percent chance of high winds in the high wind warning area from later today into Tuesday. There is a 40 percent of 4 inches or more of snowfall at lower elevations on Thursday. Thus winter statements are likely later this week. There is a high probability that cold weather statements will be needed later this week, especially for areas along/north of Highway 2. Brusda && .AVIATION... 08/12Z TAF Period Main concern over the area through this period will be the potential for strong wind gusts and mountain snow. Expect increasing winds at the surface, with strong winds possible over much of Central and North Central MT this afternoon into Tue morning. Also, rain/snow will affect the mountains, especially the Rocky Mountain front. Mountains/passes will be obscured across the CWA at times through the period. Brusda && .PRELIMINARY POINT TEMPS/POPS... GTF 51 39 50 33 / 10 30 50 60 CTB 46 32 42 25 / 10 30 40 40 HLN 49 39 50 34 / 20 50 70 80 BZN 46 36 51 31 / 10 20 60 80 WYS 33 25 38 27 / 30 70 90 90 DLN 44 37 49 34 / 10 30 40 70 HVR 42 31 45 21 / 10 30 70 30 LWT 43 32 46 25 / 10 20 60 50 && .TFX WATCHES/WARNINGS/ADVISORIES... High Wind Warning from 2 PM this afternoon to 10 AM MST Tuesday for Cascade County below 5000ft-East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Eastern Pondera and Eastern Teton-Eastern Toole and Liberty-Gates of the Mountains- Madison River Valley-Northern High Plains-Southern High Plains- Southern Rocky Mountain Front-Upper Blackfoot and MacDonald Pass. High Wind Warning from 6 PM this evening to 3 PM MST Tuesday for Bears Paw Mountains and Southern Blaine-Big Belt, Bridger and Castle Mountains-Fergus County below 4500ft-Hill County-Little Belt and Highwood Mountains-Meagher County Valleys-Northern Blaine County-Snowy and Judith Mountains-Western and Central Chouteau County. High Wind Warning until 3 PM MST Tuesday for Judith Basin County and Judith Gap. && $$ http://www.weather.gov/greatfalls