textproduct: Great Falls

KEY MESSAGES

- Widespread precipitation today, with accumulating snow most prevalent over the higher terrain of southwest MT tonight into Monday morning.

- Milder and drier conditions start by Tuesday and generally prevail through the rest of the upcoming workweek.

- With lighter winds and areas of high humidity levels, pockets of fog will be possible during late overnight and morning hours, mainly impacting central and north-central MT and the southwest valleys during the upcoming work week.

UPDATE

/Issued 811 PM MST Sun Nov 1 2026/

Mid-level cooling is occurring this evening as as the upper trough axis begins to shift east across the region. Snow levels ranged from around 7000 ft across SW MT to around 5000-6000 along the continental divide from MacDonald Pass and north. The onset of N-NW lower to mid level flow has led to some additional upslope cooling to the north of the Little Belts, where snow levels are as low as around 4000 ft. Expect snow levels to continue to lower overnight with snow at most central and SW MT passes by midnight and as low as around 4000 ft across central MT. Deeper moisture shifts east of the area with the trough axis overnight and precipitation decreases from west to east but persists in N/NW flow upslope favored areas into tomorrow morning, including around the central MT mountains and mountains of Gallatin and Madison counties. Made some adjustments to snow levels for the rest of tonight based on trends this evening but overall snow amount forecasts are on track with overnight snow accumulation of an inch or more mainly limited to elevations above 6000 ft. Hoenisch

..Fog during the upcoming week

The main time period of concern will be Sunday night into Monday morning as precip moves through the region and tapers off. Lighter winds, along with residual moisture, will provide favorable conditions for fog development. The main impact associated with this would be a reduction in visibility and the potential for freezing fog due to overnight lows expected to be near or below freezing. If areas of denser fog develop, there is the potential for that fog to remain socked in and keep daytime high temperatures 5-10 degrees cooler than expected. Through the rest of the upcoming work week, pockets of fog may develop overnight, although these would likely be patchy and limited to areas near bodies of water and valleys. -ESH

AVIATION

02/06Z TAF Period

Light precipitation will continue to slowly exit off to the east through the night. Across southwest Montana where precip wants to hang on longer, reduced visibility and low cloud decks will be a concern into the early morning hours. Terminal KWYS may have calm enough winds for a brief period of lower visibility with the development of fog, that threat will burn off quickly with sunrise. Clouds gradually move eastward, breaking up and rising through the morning. VFR conditions return to all terminals in the 2nd half of the TAF period. -JR

PRELIMINARY POINT TEMPS/POPS

GTF 42 33 52 33 / 90 100 10 0 CTB 42 28 51 29 / 80 50 0 0 HLN 44 33 49 28 / 100 60 10 0 BZN 43 31 44 24 / 90 100 50 0 WYS 41 26 42 19 / 100 90 10 0 DLN 42 32 44 26 / 100 70 10 0 HVR 44 31 47 29 / 80 90 10 0 LWT 48 30 45 28 / 80 100 70 0

TFX WATCHES/WARNINGS/ADVISORIES

None.