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 cloudy. Snow likely in the morning...then chance of snow in the afternoon. Snow accumulation up to 1 inch. Total snow accumulation up to 3 inches. Chance of snow 70 percent. Highs 13°F to 19°F.

Tonight: Partly cloudy. Lows -3°F to -9°F.

Monday: Mostly sunny. Highs 16°F to 22°F.

Monday Night: Partly cloudy in the evening then becoming mostly cloudy. Lows -2°F to 4°F.

Tuesday: Partly cloudy in the morning then becoming mostly cloudy. Highs 19°F to 25°F.

Tuesday Night: Mostly cloudy with a 20 percent chance of snow. Lows 8°F to 14°F.

Wednesday: Cloudy with a 50 percent chance of snow. Highs 20°F to 26°F.

Wednesday Night: Cloudy with a 50 percent chance of snow. Lows 3°F to 9°F.

Thursday: Cloudy with a 30 percent chance of snow. Highs 14°F to 20°F.

Thursday Night: Cloudy with a 30 percent chance of snow. Lows -1°F to 5°F.

Friday: Partly cloudy. Highs 21°F to 27°F.

Friday Night: Partly cloudy. Lows 1°F to 7°F.

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

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Mountain Weather

Overnight, a fast but intense storm delivered eleven inches of snow to the northern Gallatin Range and eight inches to the mountains around Big Sky. Strangely enough the southern Madison Range picked up two inches while the Lionhead Area, Bridger Range and mountains around Cooke City squeaked out a trace to one inch. Currently, temperatures are in the single digits Fahrenheit and winds are blowing 10 to 20 out of the North with gusts reaching close to 30 mph. Highs today will climb into the teens Fahrenheit and winds will remain out of the north at 10 to 20 mph. Snow showers will linger in the mountains through the morning hours, but skies will gradually begin to clear by this afternoon. Clear skies and colder temperatures will be on tap for tomorrow.

Snowpack and Avalanche Discussion:

Cooke City:

Consistent snowfall in the mountains around Cooke City has kept the development of persistent weak layers to a minimum. Mark rode this area a few days ago found a generally stable snowpack (video). While most slopes offer green light conditions, there are a few areas to look out for. Mid to low elevation slopes where the snowpack is thinner hold the weakest snowpack structure (photo). Be cautious when riding in these areas, specifically around creek beds or steep gullies. In upper elevation terrain, there is the possibility a stubborn wind slab could pop loose under the weight of skier or rider.

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:

Although these areas are not dealing with new snow instabilities, they have a few problems of their own.

In the mountains around West Yellowstone, a layer of facets buried 1 to 2 feet deep can be found on most aspects and elevations. Yesterday, skiers in the southern Madison Range got unstable results during stability tests and experienced a few large collapses – both signs of instability. Though this layer is gaining strength, it can't be fully trusted. Digging snowpits to assess this layer is a good insurance policy before committing to avalanche terrain.

In the Bridger Range, the snowpack is well adjusted. There are a few areas where weak snow can be found 2 to 3 feet below the surface, but this problem is not widespread. Steep slopes below ridgelines or variable areas such as the west side are places humans could possibly trigger an avalanche. Pay attention to changing snow conditions and avoid areas where you can shove your pole straight to the ground.

Today, human triggered avalanches are possible and the Avalanche Danger is rated MODERATE.

Northern Gallatin, and Northern Madison Ranges:

The surprise storm that hammered the northern Gallatin Range and mountains around Big Sky last night will certainly have a negative effect on snowpack stability. With close to .5 inches of SWE falling in a few hours, the snowpack will struggle to adjust to this rapid load.

Today, there will be two main avalanche problems.

1. Wind Slabs

2. Buried Persistent weak layers

In upper elevation terrain, moderate north winds will be strong enough to transport the new snow onto leeward slopes. Slopes facing the southern half of the compass will be most susceptible to slab formation. Fresh wind drifts will be sensitive to human triggers and will be especially dangerous in high consequence terrain.

Buried persistent weak layers do not exist on all slopes making this a tricky problem. Yesterday, I toured up Mount Ellis and found buried facets to be widespread (video). However, this is not the norm. In most areas, persistent weak layers have a sporadic distribution and appear to be most present on slopes that had a shallow snowpack during the January dry spell. Watching for signs of instability such as cracking/collapsing and digging multiple snowpits in the area you plan to ride is the best way to ensure you are not walking directly into the dragon's den.

Today, new snow, wind slabs and buried persistent layers make human triggered avalanches 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.