textproduct: Missoula

DISCUSSION

KEY MESSAGES:

- Heavy, wet snow combined with sudden snow squalls could lead to hazardous travel, localized tree damage, and power outages.

- A shift to warmer and drier weather arrives this weekend, with temperatures climbing well above normal by Sunday.

A strong area of low pressure will move through the region today, spreading showers across the area. A sharp cold front will sweep through from west to east this morning, causing gusty winds, and dragging snow levels down to around 2,500-3,500 feet by midday. Expect a period of moderate to heavy rain and snow as the front passes. A few isolated thunderstorms are possible, which could produce brief heavy downpours or sudden bursts of snow.

There is a notable risk for heavy snow bands or sudden snow squalls in southwest Montana mid-morning. This could cause rapidly dropping visibility and hazardous travel conditions, particularly on Interstate 90 and Highway 12 between Garrison Junction and Homestake Pass.

As the storm center drifts eastward, wrap-around moisture will cause widespread precipitation, mainly in the form of snow this evening into tonight. The Mission and Swan mountain ranges are in the bullseye for 12 to 24 inches of snow. Mountain passes can expect 4 to 9 inches, while valleys near the Divide may see a trace to 4 inches. Due to the heavy, wet nature of the snow combined, isolated tree damage and power outages are possible. Winter Weather Advisories are in effect for much of the mountainous terrain.

Conditions will rapidly improve as we head into the weekend. A ridge of high pressure will build over the region, clearing our skies and kicking off a significant warming and drying trend.

By Sunday, afternoon high temperatures are expected to climb approximately 10 degrees above seasonal averages, providing excellent conditions for outdoor activities. This warm, tranquil weather pattern is expected to persist into early next week. By the middle of next week, we may see another dip in the jet stream approach, which could introduce a return to cooler and more unsettled conditions, though details remain sparse this far out.

AVIATION

Conditions will deteriorate rapidly after 09/1200Z as a cold front traverses the region from west to east. Expect widespread MVFR/IFR conditions due to moderate to heavy precipitation, with snow levels dropping to 2,500 feet by midday. Of particular concern is the potential for convective snow bands or squalls in southwest Montana (near KBTM and the Divide) mid-morning, which may cause sudden LIFR visibility. Breezy winds will occur with and behind the front as well, with gusts of 20 to 25 kts being common. Persistent mountain obscurations and icing will continue through tonight, especially along the Continental Divide and the Mission/Swan ranges, as wrap-around moisture maintains low ceilings and snowfall.

MSO WATCHES/WARNINGS/ADVISORIES

MT...Winter Weather Advisory until 6 AM MDT Friday for Bitterroot/Sapphire Mountains.

Winter Weather Advisory from 6 AM this morning to noon MDT Friday for Potomac/Seeley Lake Region...West Glacier Region.

Winter Weather Advisory from 6 AM this morning to 6 AM MDT Friday for Butte/Blackfoot Region.

ID...Winter Weather Advisory until 5 AM PDT Friday for Southern Clearwater Mountains.