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: Breezy. Partly cloudy. South winds 15 to 20 mph. Highs 24°F to 30°F. Lowest wind chill readings -10°F to -20°F in the morning.

Tonight: Partly cloudy. South winds around 15 mph. Lows 3°F to 9°F.

Saturday: Partly cloudy in the morning then becoming mostly cloudy. Intermittent flurries through the day. South winds around 15 mph in the morning becoming south around 15 mph late in the afternoon. Highs 26°F to 32°F.

Saturday Night: Breezy. Mostly cloudy. Slight chance of snow in the evening...then snow likely after midnight. Snow accumulation of 1 to 2 inches. South winds 15 to 20 mph. Chance of snow 70 percent. Lows 9°F to 15°F.

Sunday: Breezy. Snow likely in the morning...then snow likely and isolated thunderstorms in the afternoon. Snow accumulation of 1 to 3 inches. Total snow accumulation 2 to 5 inches. Southwest winds 15 to 20 mph. Chance of precipitation 60 percent. Highs 19°F to 25°F.

Sunday Night: Mostly cloudy with a 50 percent chance of snow. Lows 6°F to 12°F.

Monday: Chance of snow in the morning...then snow likely in the afternoon. Moderate snow accumulations. Chance of snow 70 percent. Highs 18°F to 24°F.

Monday Night: Mostly cloudy with a 40 percent chance of snow. Lows 1°F to 7°F.

Christmas Day / Tuesday: Partly cloudy with a 20 percent chance of snow. Highs 12°F to 18°F. * Merry Christmas *

Christmas Night / Tuesday Night: Partly cloudy with a 20 percent chance of snow. Lows -3°F to 3°F. * Merry Christmas *

Wednesday: Partly cloudy with a 20 percent chance of snow. Highs 17°F to 23°F.

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

Thursday: Mostly cloudy with a 40 percent chance of snow. Highs 18°F to 24°F.

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Mountain Weather

Dry and windy weather continues. This morning temperatures were in the teens Fahrenheit and southerly winds were blowing 15 to 25 mph with gusts of 40 to 60 mph at the highest ridgetops. The exception is the Bridger Range which had temperatures in the low 20s Fahrenheit and calmer winds. Today will be partly sunny and temperatures will rise into the low 20s Fahrenheit while the Bridger Range could see temperatures approaching 30 Fahrenheit. Strong south winds will continue and only slightly ease by late afternoon. Light snowfall should come sometime Sunday with more possible for Christmas.

Snowpack and Avalanche Discussion:

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

Snowfall early this week combined with strong winds created wind slabs, the primary avalanche problem today. These wind slabs should be much less sensitive to triggering than they were a few days ago, but I doubt they have bonded to the underlying snow enough to trust them in high consequence terrain.

In many places, faceted snow exists near the ground but is weak in only a few areas. Ace Powder Guides investigated the snowpack on Mount Hebgen yesterday near West Yellowstone. They found some faceted crystals but these facets did not propagate cracks in extended column tests. What does this mean? Watch a video from the National Avalanche Center here. We have gotten similar results in many other areas.

One concern I have is the combination of a stiff wind slab resting on weak facets. A recent avalanche was spotted near the summit of Sacajawea likely involving this combination. The Big Sky Ski Patrol also found this combination in a few upper elevation, north facing slopes. I suspect it might be found in other isolated areas like the west side of the Bridger Range where a snowboarder was killed two winters ago in this exact scenario following several days of strong south winds.

For today, the presence of wind slabs that are several days old and isolated slopes that harbor weak faceted snow means human triggered avalanches are possible. For this reason the Avalanche Danger is rated MODERATE.

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. For links to all photos and videos listed in the above report, please visit this Link.

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

3. 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.