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: Mostly sunny. Areas of fog in the morning. Highs 15°F to 21°F.

Tonight: Partly cloudy. Areas of fog after midnight. Lows -1°F to 5°F.

Tuesday: Mostly cloudy. Patchy fog in the morning. Isolated snow showers in the afternoon. Chance of snow 20 percent. Highs 19°F to 25°F.

Tuesday Night: Cloudy with a 30 percent chance of snow. Lows 8°F to 14°F.

Wednesday: Cloudy with a 50 percent chance of snow. West winds around 15 mph. Highs 21°F to 27°F.

Wednesday Night: Cloudy with a 40 percent chance of snow. Lows 6°F to 12°F.

Thursday: Mostly cloudy with a 50 percent chance of snow. Highs 18°F to 24°F.

Thursday Night: Mostly cloudy with a 30 percent chance of snow. Lows 3°F to 9°F.

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

Friday Night: Partly cloudy. Lows 6°F to 12°F.

Saturday: Partly cloudy. Highs 27°F to 33°F.

Saturday Night: Partly cloudy. Lows 9°F to 15°F.

Sunday: Partly cloudy with a 30 percent chance of snow. Highs 26°F to 32°F.

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Mountain Weather

Over the past 24 hour a trace to one inch of snow has fallen in the mountains. At 4:00 AM temperatures are in the single digits above or below zero Fahrenheit and winds are blowing 10 to 20 out of the west. Today, clear skies and abundant sunshine will allow temperatures to warm into the upper teens to low twenties Fahrenheit and winds will remain out of the west at 10 to 20 mph. The building ridge of high pressure will begin to break down tonight increasing the chance of cloudy skies and light precipitation by tomorrow.

Snowpack and Avalanche Discussion:

Cooke City:

Observations from Cooke Cite continue to indicate that green light conditions exist on most slopes. However, this not a guarantee avalanches won't happen. Unstable snow can still be found on mid to low elevation slopes where the snowpack is shallow (video). Getting stuck or stepping off your sled and sinking to the ground are prime indicators the snowpack is weak and potentially unstable. Be cautious when riding in these areas, specifically around creek beds or steep gullies. In upper elevation terrain, there is the possibility skier or rider could trigger an isolated wind slab.

Today, generally safe avalanche conditions exist and the Avalanche Danger is rated LOW.

Bridger, Southern Gallatin, and Southern Madison Ranges, Lionhead area near West Yellowstone:

In the southern Madison Range and mountains around West Yellowstone, a layer of facets buried 1 to 2 feet deep remains the primary avalanche concern. On Saturday, skiers near the wilderness boundary in the Taylor Fork got unstable results during stability tests and experienced a few large collapses – both signs of instability. Although this layer is gaining strength, it continues to hold the ability to produce human triggered avalanches.

In the Bridger Range – The snowpack is deep and mostly stable near the ski area, but variable conditions exist on the west side and in the northern and southern part of the Range. Areas where the snowpack is less than a meter deep, primarily in steep rocky terrain will be the most prone to human triggered avalanches.

Today, heightened avalanche conditions exist and the Avalanche Danger is rated MODERATE.

Northern Gallatin, and Northern Madison Ranges:

On Saturday a skier triggered and was caught in an avalanche on a north facing slope near Alex Lowe Peak in the northern Gallatin Range. The caught individual lost a ski but was uninjured. The incident occurred around 6:00 PM on Saturday evening and both the caught skier and his partner ended up spending the night on the mountain side. Fortunately, they made it out safely on Sunday morning with the help of Gallatin County Search and Rescue.

It was reported that the avalanche broke an estimated 300 feet wide and ran approximately 500 vertical. The skier triggered the slide near exposed rocks where the snowpack was thin. A pencil hard wind slab resting over facets was the set up that produced the avalanche. A report on this incident will be available in the next day or two.

Since Saturday, a foot of fresh snow has fallen in the northern Gallatin Range. This has put additional stress on buried weak layers in the snowpack. A similar situation exists in the mountains around Big Sky. Yesterday, a skier remotely triggered a slide on a west facing slope in Beehive Basin – bull's eye data the snowpack is unstable. The tricky part about this situation is some slopes have buried weak layers while others do not (video). There is little consistency as to what slopes harbor buried facets, so careful snowpack evaluation is essential before committing to avalanche terrain

A more recognizable avalanche problem is wind loaded slopes. Yesterday, strong winds from the North-northwest loaded leeward slopes and cross loaded exposed terrain features. Both the Big Sky and Moonlight Basin Ski Patrols triggered sensitive wind slabs during control work. Wind loaded slopes will remain sensitive to the weight of a skier or rider.

Today, human triggered avalanches are likely on wind loaded slopes and slopes steeper than 35 degrees which have a CONSIDERABLE Avalanche Danger. All other slopes have a MODERATE Avalanche Danger.

The next advisory tomorrow morning at 7:30 a.m. 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.