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: Cloudy with scattered snow showers. Southwest winds around 15 mph in the afternoon. Chance of snow 40 percent. Highs 19°F to 25°F.

Tonight: Breezy...snow. Snow accumulation of 1 to 4 inches. Southwest winds 15 to 20 mph. Chance of snow 90 percent. Lows 12°F to 18°F.

Saturday: Breezy...snow. Snow accumulation of 2 to 3 inches. West winds 15 to 20 mph. Chance of snow near 100 percent. Highs 19°F to 25°F.

Saturday Night: Colder...cloudy. Snow likely in the evening... Then chance of snow after midnight. Snow accumulation up to 1 inch. Total snow accumulation 3 to 8 inches. West winds around 15 mph. Chance of snow 60 percent. Lows 4°F to 10°F.

Sunday: Breezy. Mostly cloudy with scattered snow showers. West winds 15 to 20 mph in the afternoon. Chance of snow 40 percent. Highs 19°F to 25°F.

Sunday Night: Mostly cloudy with scattered snow showers. Chance of snow 30 percent. Lows 4°F to 10°F.

Monday: Mostly cloudy with a 30 percent chance of snow. Highs 22°F to 28°F.

Monday Night: Mostly cloudy with a 50 percent chance of snow. Lows 9°F to 15°F.

Tuesday: Mostly cloudy with a 40 percent chance of snow. Highs 22°F to 28°F.

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

Wednesday: Mostly cloudy with a 20 percent chance of snow. Highs 24°F to 30°F.

Wednesday Night: Mostly cloudy with a 20 percent chance of snow. Lows 11°F to 17°F.

Thursday: Mostly cloudy with a 20 percent chance of snow. Highs 25°F to 31°F.

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Mountain Weather

It's snowing this morning. As of 6:00 AM the mountains near Bozeman and Big Sky received 1 to 3 inches of snow and all other areas received a trace. Temperatures were in the single digits and low teens Fahrenheit. Ridgetop winds at Bridger Bowl and Hyalite Canyon were blowing 20 to 35 mph from the West. Most other areas this morning had winds blowing 10 to 25 mph from the West. Snow will end this morning but return late afternoon or early evening.

Today will remain cold with temperatures struggling to climb out of the teens Fahrenheit and winds may increase a bit more this afternoon with the next round of snow. Snowfall today and tonight should bring 2 to 4 inches of new snow by tomorrow morning although tonight's snow should favor the mountains near Cooke City and West Yellowstone.

Snowpack and Avalanche Discussion:

Cooke City:

In many places near Cooke City, the snowpack is very deep. Where it isn't deep will be a good place to trigger an avalanche like one above Sheep Creek. Look for exposed rocks or any place you think your sled could tag a buried rock or stump.

There is another problem that is more widespread and responsible for several other recent avalanches. A very thin layer of small faceted crystals formed about a week and a half ago. Doug found this layer on most aspects yesterday buried 1.5 feet deep (photo, video). This layer is difficult to see, but it exists next to an ice crust on southerly aspects. Until more snow and wind-blown snow add stress to the snowpack, avalanches will not occur on every slope; however, the possibility is lurking on most. Make sure your partners watch from a safe location (not the toe of a slope) and consider the consequences of a slide like being pushed into trees or over rocks. For today the Avalanche Danger is rated MODERATE.

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

Many slopes have a persistent layer of faceted snow crystals buried in the upper 3 feet of the snowpack. In most cases this layer is very obvious visually, while digging, and in stability tests. Recent avalanches provide clear evidence of this layer's ability to fracture. Avalanches have occurred on Bridger Peak (accident report), Lionhead, Skyline Ridge, Fan Mountain, and Cedar Mountain. Additionally the Big Sky Ski Patrol has triggered avalanches in undisturbed areas with basically a backcountry snowpack.

Why are there tracks on many other slopes but no avalanches? This weak layer will definitely propagate a fracture (video). The missing step has been fracture initiation which is more difficult without stress from much new snow or wind-blown snow. Both snow and wind are coming. Conditions are not all doom and gloom. Some slopes lack this weak layer of facets, but it requires several snowpits to confirm this layer doesn't exists.

With a persistent weak layer buried on many slopes, human triggered avalanches remain possible. Unfortunately this layer will not show many signs of instability, and skiers and riders can hit many slopes before one slides. Today, the Avalanche Danger is rated MODERATE.

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.