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.

Today: Sunny. Patchy fog in the morning. Highs 24°F to 30°F.

Tonight: Mostly clear. Patchy fog after midnight. Lows -1°F to 7°F.

Friday: Mostly sunny. Patchy fog in the morning. Southwest winds around 15 mph late in the afternoon. Highs 22°F to 28°F.

Friday Night: Mostly clear. Southwest winds around 15 mph in the evening. Lows 0°F to 10°F.

Saturday: Mostly sunny. Highs 22°F to 28°F.

Saturday Night: Mostly clear in the evening then becoming partly cloudy. Lows -1°F to 7°F.

Sunday: Partly cloudy. Highs 23°F to 29°F.

Sunday Night: Partly cloudy in the evening then clearing. Lows 3°F to 9°F.

Monday / Martin Luther King Jr Day: Mostly sunny. Highs 23°F to 29°F.

Monday Night / Martin Luther King Jr Night: Mostly clear. Patchy fog after midnight. Lows 2°F to 10°F.

Tuesday: Mostly sunny. Patchy fog in the morning. Highs 23°F to 29°F.

Tuesday Night: Mostly clear. Lows 6°F to 12°F.

Wednesday: Partly cloudy with a 20 percent chance of snow. Highs 23°F to 29°F.

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Mountain Weather

Yesterday was warm and sunny with more of the same forecasted today. This morning mountain temperatures were near 20 degrees Fahrenheit and winds were blowing from the Southwest to Northwest 5 to 15 mph gusting 25 to 30 mph. With more sunshine today, temperatures will be in the low 30's Fahrenheit. Winds will remain westerly and wind speeds shouldn't change much.

Snowpack and Avalanche Discussion:

The Bridger, Gallatin, and Madison Ranges, the Lionhead area near West Yellowstone, and Cooke City:

There are two problems to manage today. Winds have blown new snow from Monday and formed fresh drifts and wind slabs, the primary avalanche problem. Ski Patrols at Bridger, Moonlight, and Big Sky triggered some avalanches yesterday on recently wind loaded slopes. Winds have been especially strong in the Bridger Range where Eric and Karl observed an avalanche on Saddle Peak that probably occurred on Tuesday. Being a couple days old, these wind slabs should be harder to trigger today, but I wouldn't trust them.

The other problem is a layer of facets buried 6 to 16 inches deep. Yesterday near Big Sky, my partners and I found this layer on many slopes between 8000 and 9500 feet (snowpit). On southerly aspects that had just a little wind loading, we experienced collapsing and cracking, a clear sign of unstable snow. In this area on Tuesday, a skier intentionally triggered a slide about 20 feet wide and 15 inches deep. Also on Tuesday, just outside the advisory area in the Tobacco Root Mountains, a skier triggered a slide that broke about 1 foot deep and 100 feet wide on a non-wind loaded slope.

This layer of facets remains weak and is a tricky problem because it does not have a predictable distribution in the large scale. Many slopes do not have it but some do. Because this layer is buried only about a foot deep, dig many quick pits and conduct quick stability tests as Doug recommends in this video. Looking for this layer and testing it should take less than a minute. Check out the propagation potential of a hard wind slab resting on these facets in a video from Eric and Karl doing research yesterday.

For today, wind loaded slopes steeper than 35 degrees 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) and (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.