Caution advised for snow falling off of building roofs. Park accordingly.

Dangerous avalanche conditions may already exist in many back country areas, please call the Recorded Avalanche Advisory 406-587-6981 for the most current conditions. Also, see the Avalanche Advisory posted below.

Today: Breezy...snow. Snow accumulation of 2 to 4 inches. West winds 15 to 20 mph. Chance of snow near 100 percent. Highs 20°F to 26°F.

Tonight: Cloudy. Snow likely in the evening...then chance of snow after midnight. Snow accumulation around 1 inch. Total snow accumulation 3 to 9 inches. West winds around 15 mph in the evening. Chance of snow 60 percent. Lows 2°F to 8°F.

Sunday: Mostly cloudy with a 20 percent chance of snow. West winds around 15 mph late in the afternoon. Highs 19°F to 25°F.

Sunday Night: Mostly cloudy with a 20 percent chance of snow. Southwest winds around 15 mph. Lows 2°F to 8°F.

Monday: Mostly cloudy with a 40 percent chance of snow. Southwest winds around 15 mph in the afternoon. Highs 22°F to 28°F.

Monday Night: Mostly cloudy with a 50 percent chance of snow. Lows 8°F to 14°F.

Tuesday: Mostly cloudy with a 40 percent chance of snow. Highs 21°F to 27°F.

Tuesday Night: Partly cloudy with a 20 percent chance of snow. Lows 3°F to 9°F.

Wednesday: Partly cloudy with a 20 percent chance of snow. Highs 22°F to 28°F.

Wednesday Night: Partly cloudy with a 20 percent chance of snow. Lows 7°F to 13°F.

Thursday: Partly cloudy with a 20 percent chance of snow. Highs 22°F to 28°F.

Thursday Night: Partly cloudy with a 20 percent chance of snow. Lows 6°F to 12°F.

Friday: Partly cloudy. Highs 26°F to 32°F.

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Mountain Weather

The first waves of moisture from a pacific storm are starting to impact our area. As of 6:00 AM 8 inches of snow has accumulated in the mountains near Big Sky. The mountains around West Yellowstone and Cooke City have picked up 2 to 4 inches while the mountains near Bozeman have picked up a trace to one inch. Snow will continue through the day with an additional 5 to 7 inches likely in the mountains near Big Sky and West Yellowstone. The mountains near Bozeman and Cooke City will pick up 4 to 6 inches.

Currently, temperatures are in the teens Fahrenheit and winds are blowing 10 to 25 mph out of the West-southwest with ridgetop gusts reaching into the 30s. Today, high temperatures will climb into the upper teens to mid-twenties Fahrenheit and winds will continue to blow 15 to 25 out of the west. There will likely be a spike in wind speed as the front passes later this morning. Snow will gradually taper off tonight.

Snowpack and Avalanche Discussion:

Bridger, Gallatin, and Southern Madison Ranges, Lionhead Area near West Yellowstone, and Cooke City:

Over the past week, numerous human triggered avalanches have occurred throughout our advisory area. The main reason for the uptick in avalanche activity is a layer of facets buried 1 to 3 feet deep that has been put under stress by recent incremental snowfall (video). This problem will escalate as we receive more snow and wind today.

Alongside accumulating snow, strong winds will play a major role in a rising avalanche hazard. Today, wind loaded slopes will be the primary avalanche concern. West to southwest winds will make wind slabs most prevalent on north through east facing slopes though all aspects may harbor wind drifted snow. As more snow becomes available for transport, wind slabs will become more reactive as they grow in size and distribution. Yesterday, a skier near Blackmore in the northern Gallatin Range triggered touchy wind slabs near ridgelines that propagated hundreds of feet across. Today, wind loaded slopes have the potential to break wider and deeper than one might expect.

Non-wind loaded slopes also pose an avalanche threat. As snow accumulates today and more weight is added to buried persistent weak layers, avalanches will become more likely. This problem is more difficult to predict, since not all slopes possess buried weak layers. However, buried facets have continuously shown up in snowpits throughout our advisory area. Over the past two days Doug found a layer of facets to be reactive in stability tests near Cooke City (video) and I got similar results near Hebgen Lake on Thursday. Places where the snowpack is thin, specifically around rock bands or scoured ridgelines will be likely areas to trigger deeper, more dangerous slides (photo, photo, video). A snowpit or two in the area you plan to ride is often a worthwhile investment that can help facilitate better decision making.

Today, human triggered avalanches are likely on wind loaded slopes which have a CONSIDERABLE Avalanche Danger. Non-wind loaded slopes have a MODERATE Avalanche Danger. If today's storm delivers, the Avalanche Danger could climb to HIGH on wind loaded slopes and CONSIDERABLE on non-wind loaded slopes.

Northern Madison Range:

More than 8 inches of snow has fallen in the past five hours in the mountains around Big Sky. This hefty shot of snow will create an assortment of avalanche problems. The primary avalanche concern will be wind loaded slopes. Upper elevation terrain leeward to west-southwest winds will receive the heaviest loading. Today, natural avalanches are likely and human triggered avalanches are very likely on wind loaded slopes which have a HIGH Avalanche Danger.

On non-wind loaded slopes a layer of facets buried 1 to 3 feet deep will feeling the stress from this rapid load. This layer is most widespread in mid to low elevations terrain where the snowpack is shallow. Places like Yellow Mountain are likely areas to find buried persistent weak layers. Today, continued snow will make human triggered avalanches likely on non-wind loaded slopes which have a CONSIDERABLE Avalanche Danger.

The next advisory tomorrow morning at 7:30 AM. If you have any snowpack or avalanche observations, drop us a line at mtavalanche@gmail.com or call us at: 406-587-6984.

EDUCATION, PHOTOS, SNOWPITS, and VIDEOS

1. For links to Articles, Education and (photos), (snowpits), or (videos) listed in the above report, please visit this Link.

2. They have recently uploaded more photos and snowpits to their web site, more than what are linked in the advisory above.

3. They have creating a series of "How To…" stability test videos. So far they have clips on performing a CT and ECT. They are located under Stability Tests on their Resources page.

Information provided by Doug Chabot, Mark Staples, and Eric Knoff from the Gallatin National Forest Avalanche Center. For Photos and Videos, please visit the Avalanche Centers Website!

If you have any snowpack or avalanche observations, drop them a line at mtavalanche@gmail.com or call: 406-587-6984.

For detailed Avalanche Terms utilized here, please see the Avalanche Glossary.