textproduct: Great Falls

KEY MESSAGES

- Light mountain precipitation tonight into early Tuesday.

- Gusty winds return to the Rocky Mountain Front tonight and spread further onto the plains Tuesday.

- Temperatures trend warmer for the latter half of the week as upper level ridging builds in, perhaps challenging some record highs.

DISCUSSION

/Issued 116 PM MST Mon Nov 9 2026/

- Meteorological Overview:

Initially zonal flow aloft trends more southwesterly through the remainder of the day and into tonight as another wave moves onshore from the Pacific Northwest. One initial impact from this system will be for increased winds and gusts along the immediate eastern slopes of the Rocky Mountain Front, though ridgetop stability is rather mediocre at this point in the event. Cross barrier flow is largely around or less than 50kts at 700mb, so confidence in any strong winds (sustained wind 50+ mph or a gust of 75+ mph) materializing at the surface in the aforementioned area remains low. The other initial impact will be for mainly light mountain precipitation along the Continental Divide tonight into early Tuesday. Snow levels are rather high for this event, briefly dropping below 6,500 ft in a few localized areas. Given precipitation amounts look light and that snow levels are so high, impacts from any snow that falls will be minimal.

Heading into the daytime hours Tuesday the flow aloft trends a bit more northwesterly as the main trough axis exits eastward. Daytime mixing will result in gusty winds spreading over the remainder of the plains during the day. winds aloft at the top of the mixed layer does look to briefly flirt with 50kts, but is not forecast to be persistent in time nor location. While a few isolated gusts to 58 mph will be reasonable tomorrow over the plains, they look too infrequent in any one area to warrant a High Wind Warning. Trends will continue to be monitored for any changes in thinking for this timeframe.

The latter half of the week will feature a warming trend thanks to an upper level ridge building in across the west. Well above average temperatures are forecast, with a few locations approaching daily record highs at times. The ridge trends eastward ahead of troughing this weekend, though there remains uncertainty how quickly this trend ensues. -AM

- Forecast Confidence & Scenarios:

Winds Tuesday: The probability for a 58 mph gust near Cut Bank and Geyser is roughly 30%. Further west along the immediate eastern slopes of the Rocky Mountain Front the probability for a 75 mph gust in and around Browning peaks at 20% or so. While a few isolated gusts of criteria will occur, they look to be too isolated to warrant High Wind Warnings at this time. -AM

AVIATION

10/00Z TAF Period

VFR conditions will prevail through the TAF period. As the next disturbance arrives, low and mid-level clouds will increase through the overnight hours, particularly along the Continental Divide with mountain obscuration possible between 10/06Z and 10/18Z. Precipitation is generally expected to stay within the vicinity of the mountains across Central and Southwest Montana, however, an isolated shower cannot be ruled out across the plains and lower elevation valleys of Southwest Montana. Winds will increase out of the south initially after 10/12Z and veer to the west by the afternoon with gusty conditions expected across the region through at least 11/00Z. -thor

PRELIMINARY POINT TEMPS/POPS

GTF 41 58 43 66 / 10 10 0 0 CTB 36 53 38 62 / 0 0 0 0 HLN 37 56 37 59 / 10 10 0 0 BZN 36 56 33 59 / 0 10 0 0 WYS 27 46 24 49 / 0 0 0 0 DLN 35 55 32 57 / 0 0 0 0 HVR 34 60 35 66 / 10 30 0 0 LWT 38 56 36 65 / 0 10 0 0

TFX WATCHES/WARNINGS/ADVISORIES

None.