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.

Rest Of Today: Cloudy. Snow likely late in the morning...then chance of snow in the afternoon. New snow accumulation around 1 inch. Total snow accumulation 1 to 3 inches. Highs 20°F to 26°F. Chance of snow 70 percent.

Tonight: Cloudy with a 50 percent chance of snow. Areas of blowing snow after midnight. Lows 8°F to 14°F. Southwest winds around 15 mph.

Sunday: Breezy. Snow likely. Areas of blowing snow. Snow accumulation of 1 to 3 inches. Highs 17°F to 23°F. Southwest winds 15 to 20 mph. Chance of snow 60 percent.

Sunday Night: Snow likely. Snow accumulation of 1 to 3 inches. Lows 10°F to 16°F. Southwest winds around 15 mph. Chance of snow 70 percent.

Monday: Breezy. Snow likely. Areas of blowing snow. Snow accumulation of 4 to 6 inches. Total snow accumulation 6 to 12 inches. Highs 23°F to 29°F. Southwest winds 15 to 25 mph. Chance of snow 70 percent.

Monday Night: Breezy. Cloudy with a 50 percent chance of snow. Areas of blowing snow. Lows 12°F to 18°F.

Tuesday: Mostly cloudy with a 40 percent chance of snow. Highs 15°F to 21°F. Lowest wind chill readings -10°F to -20°F in the afternoon.

Tuesday Night: Colder. Mostly cloudy with a 30 percent chance of snow. Lows -2°F to 4°F.

Wednesday: Partly cloudy with a 20 percent chance of snow. Highs 9°F to 15°F.

Wednesday Night: Partly cloudy with a 20 percent chance of snow. Lows -2°F below to 4°F.

Thursday: Not as cold. Partly cloudy. Highs 19°F to 25°F.

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

Friday: Partly cloudy. Highs 25°F to 31°F.

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Mountain Weather

Over the past 24 hours 1 to 3 inches of low density fell in most mountain locations with the exception of the northern Madison Range which picked up 4 inches. Currently, temperatures are in the mid to high teens F and winds are light, blowing 5 to 10 mph out of the West-southwest. Today, temperatures will warm into the low 20°s F under partly cloudy skies and winds will continue to blow 5 to 10 mph out of the West-southwest. There is a slight chance of snow showers in the southern Mountains, but today should remain mostly dry. Another storm is forecasted to impact our area Sunday night into Monday.

Snowpack and Avalanche Discussion:

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

It's not even officially winter, yet - but it sure feels like it. After two weeks of near continuous snowfall, the snowpack in southwest Montana is well above average (NRCS Snow Update). In terms of snowpack stability, a deeper pack typically means a stronger pack. This has proven generally true so far.

Although our snowpack is looking good, it's not perfect. Today, the primary avalanche concern will be new snow instabilities. Avalanches failing on storm interfaces in the top 1 to 2 feet of the snowpack remain possible. On Thursday, a skier in the Bridger Range triggered a slab avalanche on Saddle Peak that failed within the storm snow. Fortunately, the skier was not caught. Also, Doug got unstable results on a storm interface at Bacon Rind on Wednesday and Snowmobilers got similar results during stability tests in Teepee Basin in the southern Madison Range Yesterday. Although our snowpack data is limited from Cooke City, I expect these types of instabilities to exist in that area as well.

This type of avalanche problem typically doesn't live long but remains a concern as long as there's new snow. Avoiding slopes steeper than 35 degrees, especially slopes that have been wind affected is the best way to mitigate this problem. Fortunately, winds have been relatively calm the past few days keeping transport to a minimum.

A less likely, but potentially more dangerous situation are avalanches failing on deeper layers in the snowpack. Large, natural avalanches in the northern Bridger Range earlier in the week are a prime example of this problem. Yesterday, Mark and I investigated one of these slides in Hollywood Bowl south of Frazier Basin. This avalanche failed on a thin layer of facets 1 to 2 feet above the ground and likely occurred during a rapid loading event this past Wednesday.

Buried facets are not widespread throughout our forecast area, but continue to make their presence known (see Doug's video of Bacon Rind). Triggering a slide on a deeper layer will be most likely in steep, rocky terrain where the snowpack is thinner. Carefully evaluating snow stability and terrain is a wise idea before committing to steep slopes

Today, heightened avalanche conditions exist and human triggered avalanches are possible. For this reason the Avalanche Danger is rated MODERATE.

I will issue 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.

PHOTOS, SNOWPITS, and VIDEOS

1. We've recently uploaded more photos and snowpits to our web site, more than what are linked in the advisory.

2. We're creating a series of "How To…" stability test videos. So far we've got clips on performing a CT and ECT. There are located under Stability Tests on the 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.