textproduct: Missoula

DISCUSSION

KEY MESSAGES:

- Unsettled, cool, and showery conditions persist into the weekend.

- Mountain snow this weekend will create difficult conditions for backcountry recreation, especially along the Continental Divide.

- Widespread frost and freezing temperatures are highly likely Sunday through Tuesday mornings.

At 1am, the snow level remains between 5500-6000 feet, we do expect them to lower over the weekend eventually to 4000 feet or lower. What does this mean, well the potential for a slushy accumulation during hours of darkness at mountain pass level and higher. Sun angles and lack of moderate precipitation intensities will keep any impacts during the day to people ill- prepared for cool and wet conditions. Those that are recreating in the mountains should plan for cool and showery conditions, that can produce hypothermia if lacking preparation. Showers will continue through the weekend under cyclonic flow, mainly in the mountains with light precipitation amounts, except along the ID/MT border, Mission Mountains, and Glacier National Park Region where 0.50 to 1.00 inch of water equivalent is possible by Sunday evening. That same time frame and those mountains ranges will also have the potential for 4 to 12 inches of snow, mainly above 5000 feet. Higher valleys of southwest MT could receive 1 to 5 inches of snow, mainly tonight through Sunday morning.

Note: those forecast snow amounts are for a period of time longer than our current winter weather advisories, hence the differences in amounts.

By Monday, temperatures will be 5-10 degrees below normal for this time of year. Kids will need jackets for the morning bus and be carrying them home during the afternoon. Sensitive vegetation will need care both Monday and Tuesday mornings, as temperatures lower into the 20s in western Montana and higher valleys of north- central ID. Cloud cover over the weekend, will likely keep overnight lows above freezing below 4000 feet.

Tuesday through Friday will see a warming trend with dry conditions. By Friday, temperatures could be 5-8 degrees warmer than normal as a chance for showers returns.

AVIATION

Widespread showers have arrived, favoring KGPI, KMSO, and KHRF. Expect widespread lowered ceilings down to about 2500 feet by Saturday morning, as well as continued precipitation through about midday transitioning to scattered showers and thunderstorms in the afternoon. Precipitation will obscure terrain throughout the Northern Rockies airspace.

MSO WATCHES/WARNINGS/ADVISORIES

MT...Winter Weather Advisory from midnight Saturday night to midnight MDT Sunday night for Bitterroot/Sapphire Mountains... Butte/Blackfoot Region...Potomac/Seeley Lake Region...West Glacier Region.

ID...None.