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: Mostly sunny in the morning then becoming partly cloudy. Highs 16°F to 22°F. Lowest wind chill readings -14°F to -24°F in the morning.

Tonight: Cloudy. Slight chance of snow in the evening...then chance of snow after midnight. Chance of snow 50 percent. Lows 1°F to 7°F.

Sunday: Mostly cloudy with a 40 percent chance of snow. Highs 15°F to 21°F.

Sunday Night: Mostly cloudy in the evening then becoming partly cloudy. A 20 percent chance of snow. Lows -2°F to 4°F.

Monday: Partly cloudy. Highs 14°F to 20°F.

Monday Night / New Years Eve: Partly cloudy. Lows -2°F to 4°F. * Happy New Year *

Tuesday / New Years Day: Partly cloudy. A 20 percent chance of snow in the afternoon. Highs 15°F to 21°F. * Happy New Year *

Tuesday Night / New Years Night: Partly cloudy. Lows 0°F to 6°F. * Happy New Year *

Wednesday: Partly cloudy. Highs 17°F to 23°F.

Wednesday Night: Partly cloudy in the evening then clearing. Lows -5°F to 5°F.

Thursday: Mostly sunny. Highs 21°F to 27°F.

Thursday Night: Partly cloudy. Lows 2°F to 8°F.

Friday: Partly cloudy. Highs 22°F to 28°F.

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

Mountain Weather

Over the past 24 hours a trace to one inch of snow fell in the mountains. Currently, temperatures are in the single digits Fahrenheit and westerly winds are blowing 5 to 15 mph. Today, temperatures will warm into the high teens to low twenties Fahrenheit and winds will continue to blow 5 to 15 mph from the west. Skies will become partly to mostly cloudy by this afternoon as a weak storm system approaches. Light snow is likely by tomorrow morning with 1 to 3 inches possible by tomorrow afternoon.

Snowpack and Avalanche Discussion:

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

Triggering an avalanche today will be a lot like hitting the bull's eye on a dart board. It could take dozens of throws or you could get lucky (or in this case unlucky) on the first toss. Yesterday, I observed this 'dart board' scenario in the mountains around Cooke City. I was amazed at the terrain people were riding without triggering slides. That was, until we came across a slope that had recently avalanched (photo, video). This slide occurred on a southwest facing slope what was heavily wind loaded.

Today, the primary avalanche concern will be wind slabs. Yesterday, gusty west-northwest winds developed sensitive soft slabs on leeward slopes. Both the Moonlight Basin and Big Sky Ski Patrols reported triggering fresh wind slabs during control work. Also, a skier near Cooke City reported triggering soft slabs on east facing slopes below ridgelines.

Winds died down yesterday afternoon allowing recently formed wind drifts a little time adjust. In areas where wind deposited snow rests over a thin layer of facets, human triggered avalanches will be more likely. On slopes that lack near surface instabilities, fresh wind drifts will be more stubborn. This creates a tricky scenario. The best approach today will be to recognize and avoid wind loaded slopes, especially those in steep, upper elevation terrain.

There is a chance that slides could fail on faceted layers near the ground. Impacting deeper weak layers will be easiest on slopes that have a thin and variable snowpack. Once a weak layer collapses, it can propagate into areas where the snowpack is deeper (photo).

Right now more slopes are stable than unstable, but human triggered avalanches remain possible and 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 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.