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: Partly cloudy in the morning then becoming mostly cloudy. Occasional flurries in the afternoon. Southwest winds around 15 mph late in the afternoon. Highs 21°F to 27°F.

Tonight: Cloudy. Occasional flurries. Lows 3°F to 9°F.

Monday: Cloudy. Slight chance of snow in the morning...then chance of snow in the afternoon. Southwest winds around 15 mph late in the afternoon. Chance of snow 30 percent. Highs 18°F to 24°F.

Monday Night: Cloudy with a 50 percent chance of snow. Southwest winds around 15 mph. Lows 10°F to 16°F.

Tuesday: Cloudy with a 50 percent chance of snow. Southwest winds around 15 mph. Highs 22°F to 28°F.

Tuesday Night: Cloudy with a 50 percent chance of snow. Lows 14°F to 20°F.

Wednesday: Mostly cloudy in the morning then becoming partly cloudy. A 20 percent chance of snow. Highs 26°F to 32°F.

Wednesday Night: Mostly cloudy with a 30 percent chance of snow. Lows 11°F to 17°F.

Thursday: Cloudy with a 50 percent chance of snow. Highs 19°F to 25°F.

Thursday Night: Colder. Mostly cloudy with a 30 percent chance of snow. Lows 0°F to 6°F.

Friday: Mostly cloudy with a 20 percent chance of snow. Highs 11°F to 17°F.

Friday Night: Mostly cloudy with a 20 percent chance of snow. Lows -5°F to 1°F.

Saturday: Mostly cloudy with a 20 percent chance of snow. Highs 5°F to 11°F.

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

Mountain Weather

There is no new snow to report, but a weak weather disturbance could deposit a trace to one inch of snow by this afternoon. This morning mountain temperatures are in the 20s Fahrenheit with the exception of the West Yellowstone area where temperatures are in the single digits Fahrenheit. Winds are blowing 15 to 30 out of the West-southwest with gusts in Hyalite reaching close to 50 mph. Today, temperatures will warm into the upper 20s to low 30s Fahrenheit and winds will continue to blow 15 to 30 out of the West-southwest. There is a chance of mountain snow showers through the day, but accumulations will be light. A stronger storm system is forecasted tomorrow night into Tuesday.

Snowpack and Avalanche Discussion:

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

Taking time to assess snowpack and terrain can be difficult when generally safe avalanche conditions exist. However, assuming all slopes are safe during a low avalanche danger can be costly. This was demonstrated by the human triggered avalanche in the Hourglass chute north of Bridger Bowl on Thursday (video, video, photo1, photo2). This slide occurred on a slope where a wind slab formed over a thin layer of facets. While investigating the slide on Friday, both Mark and I felt this chute was one of the few places in the area with unstable snow.

Today, wind slabs resting over facets are the main avalanche concern. While generally green light conditions exist in most areas, a slab-facet combination can be found on isolated slopes in exposed, upper elevation terrain (photo). The challenge today will be figuring out which wind loaded slopes have buried weak layers and which do not. If you're not willing to dig a snowpit, then it's probably best to avoid the most dangerous slopes – the ones steeper than 35 degrees that drain over cliffs or into gullies or trees.

* * NEW WEAK LAYER * *

Recent dry weather has faceted the snow surface in many areas (video, article). Yesterday, I skied in the southern mountains near West Yellowstone and found a well-developed layer of near surface facets on all aspects and elevations. This layer has also been observed in the mountains near Bozeman and Big Sky as well as the Cooke City area. Currently, this layer does now pose a major avalanche threat, but once a slab of snow builds on top of it, we'll have the right recipe for avalanches.

Today, generally safe avalanche conditions exist and the Avalanche Danger is rated LOW.

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.