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: Mostly sunny. Highs 27°F to 33°F.

Tonight: Mostly clear. Lows 6°F to 12°F.

Sunday: Mostly sunny. Southwest winds around 15 mph in the afternoon. Highs 27°F to 33°F.

Sunday Night: Partly cloudy. Lows 7°F to 13°F.

Monday: Partly cloudy with isolated snow showers. Southwest winds around 15 mph in the afternoon. Chance of snow 20 percent. Highs 24°F to 30°F.

Monday Night: Partly cloudy. Lows 11°F to 17°F.

Tuesday: Not as cold. Partly cloudy. Highs 32°F to 38°F.

Tuesday Night: Partly cloudy. Lows 13°F to 19°F.

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

Wednesday Night: Mostly cloudy in the evening then becoming partly cloudy. Lows 10°F to 16°F.

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

Thursday Night: Partly cloudy in the evening then becoming mostly cloudy. Lows 11°F to 17°F.

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

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Mountain Weather

Snow showers yesterday morning produced 2 to 4 inches in most areas. This morning temperatures were in the teens Fahrenheit and westerly winds were blowing 10 to 15 mph with gusts 20 to 30 mph. Today will be mostly sunny with temperatures in the low 30s Fahrenheit. Westerly winds will blow 10 to 25 mph.

Snowpack and Avalanche Discussion:

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

Today will have perfect conditions for human triggered avalanches - recent heavy snow, lurking weaknesses in the snowpack combined with sunshine and good powder. What worries me is that many slopes are stable, and signs of instability may not be obvious before triggering an avalanche.

However, mother nature gave us some good clues yesterday.

1. Ace Powder Guides spotted 10 recent natural avalanches on S facing slopes on Kirkwood Ridge near West Yellowstone. These were 70 to 100 feet wide and broke about 1.5 feet deep.
2. Gallatin National Forest Snow Rangers remotely triggered a small slide along Beaver Creek on a Southeast facing slope. It was 12 inches deep and about 25 feet wide.
3. Two slides were remotely triggered on a West facing slope in Beehive Basin. Both were about 1 to 1.5 feet deep and 50 feet wide.
4. The Moonlight Basin Ski Patrol spotted a small slide on Fan Mountain in a "seemingly shallow faceted area" with a heavy load of new snow.
5. Eric spotted a natural avalanche (photo) on Mount Blackmore and experienced collapsing and cracking on Southeast facing slopes in areas that previously had a thin snowpack (video).
6. Two days ago on Mount Ellis, Eric experienced widespread collapsing and cracking (photo).
7. I saw one small slide near McAtee Basin involving just the new snow on a North aspect, then experienced collapsing and cracking on a South facing slope along Buck Ridge (video).
8. A skier near Cooke City observed shooting cracks in the snowpack at lower elevations and significant wind drifting at higher elevations (photo).

There are several avalanche problems today. At higher elevations in many places the snowpack is deep and strong, and the avalanche problem is fresh wind slabs and drifts. Fortunately these are usually easy to see and avoid. Another trickier problem is weak facets under the new snow. These facets exist on many slopes that previously had less than 2.5 feet of snow due to low elevation or wind scouring. They also exist on slopes that were sheltered from strong wind events in January and developed a thin layer of near surface facets.

These avalanche problems are confusing and tricky. The simple solution is to avoid any fresh wind slabs and drifts. Also, assume every slope has weak facets under the new snow until you have enough evidence to convince yourself they will be absent from the slopes where you hope to ski or ride. This is not an impossible task but will require careful observations.

Many slopes can easily produce human triggered avalanches today and many will not. These are dangerous avalanche conditions that require careful snowpack evaluations to ski or ride in avalanche terrain. For today the Avalanche Danger is rated CONSIDERABLE.

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.