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: Snow in the morning...then numerous snow showers in the afternoon. Snow accumulation of 2 to 4 inches. South winds around 15 mph. Chance of snow near 100 percent. Highs 27°F to 33°F.

Tonight: Snow. Snow accumulation of 5 to 8 inches. Chance of snow near 100 percent. Lows -1°F to 5°F.

Friday: Colder. Snow in the morning...then snow likely in the afternoon. Areas of blowing snow through the day. Snow accumulation of 1 to 3 inches. Total snow accumulation 8 to 16 inches. North winds around 15 mph. Chance of snow near 100 percent. Highs 4°F to 10°F. Wind chill readings -12°F to -22°F.

Friday Night: Colder. Mostly cloudy. Chance of snow in the evening. North winds around 15 mph in the evening. Chance of snow 30 percent. Lows -8°F to -16°F.

Saturday: Partly cloudy. Highs 1°F to 7°F. Lowest wind chill readings -17°F to -27°F in the morning.

Saturday Night: Partly cloudy. Lows -7°F to -13°F.

Sunday: Partly cloudy. Highs 3°F to 9°F. Lowest wind chill readings -20°F to -30°F in the morning.

Sunday Night: Partly cloudy. Lows -7°F to -15°F.

Monday: Partly cloudy. Highs 4°F to 10°F.

Monday Night: Mostly cloudy with a 40 percent chance of snow. Lows -6°F to 0°F.

Tuesday: Not as cold. Mostly cloudy with a 40 percent chance of snow. Highs 15°F to 21°F.

Tuesday Night: Mostly cloudy with a 20 percent chance of snow in the evening...then partly cloudy after midnight. Lows 0°F to 8°F.

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

 Hazardous Weather Forecast  Gibbon Falls Forecast  Mammoth Forecast  Midway Forecast  Norris Forecast  Old Faithful Forecast 

Mountain Weather

No snow fell yesterday or overnight, but snowfall started this morning near West Yellowstone with 2 inches of new snow at 6:00 AM and snow just beginning near Big Sky. This morning, mountain temperatures were mostly in the 20s Fahrenheit except in the Bridger Range where temperatures were near freezing. Winds eased a little this morning and were blowing 10 to 20 mph from the South-southwest with gusts of 30 mph; however, winds remained strong in Hyalite Canyon where they were averaging 30 mph with gusts of 50 mph.

A slow-moving winter storm will bring snowfall throughout the advisory area today. Temperatures should drop a few degrees and reach 0 degrees Fahrenheit by tomorrow morning. Winds will also decrease. By tomorrow morning 8 to 10 inches of snow will fall near in the mountains West Yellowstone and Cooke City, 6 to 8 inches near Big Sky, and 3 to 6 inches near Bozeman. All the meteorological factors for snow are aligning well today making higher snow amounts possible. Snowfall will continue through Friday.

Snowpack and Avalanche Discussion:

The Bridger and Northern Gallatin Ranges:

The Bridger and northern Gallatin Ranges have a similar weak layer (video) as the rest of the advisory area, but they only received an inch or two of snow early this week. While these areas have not received much new snow, they experienced equally strong winds that stripped some slopes to bare ground. These strong winds created widely variable surface conditions, thus the distribution of the near-surface weak layer is random and will be tricky to map once it is buried by today's snowfall. For today the Avalanche Danger is rated MODERATE on all wind-loaded terrain and LOW Avalanche Danger on all other slopes.

Southern Gallatin and Madison Ranges, the Lionhead area near West Yellowstone and Cooke City:

Snowfall on Monday and Tuesday totaled about 5 inches near Big Sky, about 7 inches near West Yellowstone and 12 inches near Cooke City. Since then strong winds from the Southwest easily redistributed this snow. Near Cooke City yesterday, my partner and I found widespread wind drifts and wind slabs resting on lower density snow, a great recipe for avalanches. Although we found only one small, natural avalanche, wind loaded slopes would have been prime places for human triggered slides.

Fresh wind slabs always create an avalanche problem, but a longer lasting problem is a layer of weak, faceted snow that formed on the snow surface during dry weather after New Year's. In many places this layer is near-surface facets, and in a few places (Beehive Basin and Town hill near Cooke City) this layer is surface hoar (photo). The type of crystal doesn't matter because both are weak and will remain fragile for weeks to come (video). This layer will be tricky because it exists on many slopes in some areas and exists on only a few slopes in areas like Cooke City.

For today, any slope with a wind-load has a CONSIDERABLE Avalanche Danger since it's likely someone can trigger an avalanche. On slopes without a wind-load the Avalanche Danger is rated MODERATE.

* * Avalanche Danger Rising * *

Be heads up today. As quickly as snow falls, the avalanche danger will rise quickly too and could easily become HIGH today or even reach avalanche warning criteria. Stay tuned. If such criteria are met, we could issue a warning this afternoon.

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) and (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.