WEATHER ALERT DAY has been declared for Friday in northwest Montana and for Saturday in the Gallatin Valley as heavy accumulating snow, freezing rain, gusty winds and major travel impacts are expected.
A winter storm will bring heavy snow and gusty easterly winds, particularly in the Flathead Valley and West Glacier region today. The cold air is a bit slower than originally forecast, but a flash freeze situation on the roads appears possible as the evening commute gets underway.
Snowfall rates could become moderate to heavy this evening, with 4 to 8 inches snow possible for localized areas around the Flathead Valley. Wind gusts of 30 to 40 mph will create blowing snow, reducing visibility at times. Light to moderate snow is likely with accumulations of up to 3 inches in valleys along and south of I-90.
There will be a brief period of a mix of rain, snow and freezing rain in lower valleys such as the Mission, Missoula and Bitterroot Valleys. A full list of the National Weather Service Warnings and Advisories are posted below.
Overnight through early Saturday afternoon, a secondary round of heavy snowfall will impact parts of southwest Montana near and east of I-15. The Gallatin Valley snowfall rates up to 1/2″ per hours and could see 2-6″ of additional snowfall with moderate to major travel impacts before this system begin to clear.
Lingering snow showers are expected Saturday west of the divide, especially in higher elevations and northern valleys. Additional accumulations will be light, generally under 3 inches. Morning temperatures near freezing may lead to icy conditions on untreated roads. Highs will climb into the mid-30s, with lows in the upper 20s.
Our next weather maker will impact the area late Saturday through Monday, bringing another round of snow and mixed precipitation.
Snowfall totals of 3 to 6 inches are possible at mountain passes, including Lookout, Marias, and Lost Trail.
Valleys may see light snow or rain, with a risk of black ice as temperatures drop overnight. Highs will be slightly warmer, in the mid-30s to low 40s, with lows in the upper 20s.
WINTER STORM WARNING through 5 AM Saturday for the Flathead/Mission Valleys due to heavy snow, flash freeze, and mixed precipitation expected. Total snow accumulations between 4 and 8 inches and ice accumulations around a light glaze.
WINTER STORM WARNING through 5 AM Saturday for the West Glacier Region due to heavy snow and blowing snow expected. Total snow accumulations between 8 and 12 inches.
WINTER STORM WARNING until 5 PM Saturday for Little Belt and Highwood Mountains, Snowy and Judith Mountains, Big Belt, Bridger and Castle Mountains, including the following locations: Deep Creek Pass, Bozeman Pass, Maudlow, Battle Ridge Pass, Neihart, Kings Hill Pass, Trident, and Monarch. Heavy snow. Additional snow accumulations between 5 and 10 inches
WINTER STORM WARNING from 5 AM Saturday until 5 PM Saturday for Gallatin Valley, Gallatin and Madison County Mountains and Centennial Mountains. Including the following locations: Bozeman, West Yellowstone, Big Sky, Raynolds Pass, and Targhee Pass. Total snow accumulations in Gallatin Valley between 2 and 6 inches and between 4 and 12 inches in the mountains.
WINTER WEATHER ADVISORY through 8 AM Saturday for the Kootenai/Cabinet Region. Total snow accumulations 2 to 5 inches Eureka to Whitefish, and Libby, then 6 to 10 inches Bull Lake and between Libby and Happy`s Inn, 12 to 18 inches of snow in the mountains closer to the Idaho border.
WINTER WEATHER ADVISORY through 8 AM Saturday for the Lower Clark Fork Region. Total valley snow accumulation of 1 to 3 inches. Total snow accumulation at Lookout Pass 6 to 10 inches. Ice accumulations around a light glaze.
WINTER WEATHER ADVISORY through 8 AM Saturday for the Missoula/Bitterroot Valleys. Snow accumulations of 1 to 3 inches are expected, with isolated higher amounts nearing 6 inches.
WINTER WEATHER ADVISORY through 8 AM Saturday for the Bitterroot/Sapphire Mountains. This advisory includes Lolo and Lost Trail Passes. Additional snow accumulations of 3 to 6 inches at passes, and 2 to 5 inches in the valleys. Ice accumulations around a light glaze.
WINTER WEATHER ADVISORY through 8 AM Saturday for the Butte/Blackfoot Region. Total snowfall 1 to 2 inches south and west of Garrison Junction including Butte, 3 to 5 inches MacDonald Pass and Ovando.
WINTER WEATHER ADVISORY through 8 AM Saturday for the Potomac/Seeley Lake Region. Total snow accumulations of 3 to 5 inches Seeley Lake to Clearwater Junction, 1 to 2 inches elsewhere. Ice accumulations around a light glaze.
WINTER WEATHER ADVISORY from 8 PM Friday until 4 AM Saturday for the Southern Clearwater Mountains. Snow and black ice expected. Total snow accumulations up to 3 inches in the valleys, but 3 to 6 inches at Lolo Pass.
WINTER WEATHER ADVISORY from 5AM to 5PM Saturday for the Madison River Valley, including Cameron, McAllister, Ennis, Norris and Jeffers. Total snow accumulations between 2 and 4 inches.
WINTER WEATHER ADVISORY from 5AM to 5PM Saturday for the Missouri Headwaters, including Pony, Harrison, Whitehall, Three Forks and Willow Creek. Total snow accumulations up to 3 inches.
AVALANCHE WARNING until 5 AM Saturday for the mountains around Cooke City. The avalanche danger is HIGH on all slopes. Natural and human triggered slides are very likely.
