textproduct: Missoula

DISCUSSION

KEY MESSAGES:

- A trough approaching the west coast will usher in a pattern change this weekend.

- The pattern over the next week will remain active with troughs moving through the region.

A closed low off the west coast is filling in and will become a trough by the time it arrives in the northern Rockies Saturday morning. A larger, stronger trough will remain off the US west coast setting up southwesterly flow into the region. The southwest flow will cause warmer temperatures and rising snow levels, and while the trough will also bring some moisture, it won't be much. Over all, it will be a breezy, wet weekend, especially in the mountains as a result.

Some cooler air will make it into the region by Monday, causing snow levels to trend down slowly, but steadily. As the broader area of troughing migrates eastward, it will bring more cold air with it, and snow levels will reach around 4,000ft late Tuesday or early Wednesday. So some light snow showers could reach valley floors in western Montana by mid or late next week.

AVIATION

Increased southwest winds aloft, decreasing stability, and thicker cloud cover this morning, and a developing easterly wind gradient is making it more difficult for fog to sustain this morning. A large low pressure system approaching the west coast and the ridge progressing east will cause southwest winds to increase today and cause VFR conditions across the region once the fog clears from northwest Montana.

MSO WATCHES/WARNINGS/ADVISORIES

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