textproduct: Missoula

DISCUSSION

KEY MESSAGES:

- Quiet Weekend: Snow showers end this evening, then patchy fog potential, mix sun/clouds.

- Wintry Weather Returns Monday/Tuesday: Moderate pass level impacts, wintry mix (messy commute potential) in the valleys.

- Gusty winds/organized snow showers mid next week

Scattered snow showers will continue into this afternoon, leading to brief accumulations on roadways and rapidly changing driving conditions. However, this activity will quickly subside around sunset. High pressure ridging follows for the weekend, bringing a mix of sunshine and high-to-mid-level clouds as daytime temperatures gradually moderate. Patchy morning fog and stratus will be a concern, especially across northwest Montana.

Precipitation will begin early Monday morning and last through Tuesday as a weak-to-moderate atmospheric river pushes through the Northern Rockies. A notable concern is moderate impacts at pass levels, with a 50-60% probability of at least 6 inches of snow for the MT/ID border passes.

Precipitation type remains the primary uncertainty. Currently, NBM snow levels appear too high for Monday morning given the warm air advection pattern and limited mixing, so we have trended these downward. This adjustment introduces the potential for light snow in the valleys of northwest Montana early Monday. Thereafter, enhanced mixing should allow snow levels to rise, transitioning valley precipitation to a wintry mix, most likely rain and snow at night, changing to rain during the afternoon hours. Overall, prepare for slick pass-level roads and potentially messy valley roads, primarily during the nighttime and morning periods.

The character of the event shifts as an upper-level trough and cold front pass through late Tuesday into Wednesday. Westerly winds will increase alongside a threat for organized snow showers and banding. We will be watching this period closely for more significant valley impacts. Looking further ahead, gusty winds are expected through the second half of next week. Friday, in particular, stands out among guidance as a notably windy period and will be another timeframe to monitor as we get closer.

AVIATION

Scattered snow showers will continue into this afternoon, leading to brief accumulations and low visibility for KMSO, KHRF and KBTM. However, this activity will quickly subside around sunset. A ridge of high pressure this weekend will bring a mix of sun and clouds, with patchy fog each morning, especially across northwest Montana.

MSO WATCHES/WARNINGS/ADVISORIES

MT...None. ID...None.