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. Also, see the Avalanche Advisory posted below.

Today: Partly cloudy. Highs 34°F to 40°F.

Tonight: Cloudy. Scattered snow showers after midnight. Southwest winds around 15 mph. Chance of snow 50 percent. Lows 21°F to 27°F.

Sunday: Breezy. Snow showers. Snow accumulation of 3 to 5 inches. West winds 15 to 20 mph. Chance of snow 80 percent. Highs 29°F to 35°F.

Sunday Night: Breezy...colder. Cloudy with snow showers likely. Snow accumulation of 2 to 3 inches. Total snow accumulation 5 to 8 inches. West winds 15 to 20 mph. Chance of snow 60 percent. Lows 4°F to 10°F.

Monday: Mostly cloudy in the morning then becoming partly cloudy. A 30 percent chance of snow showers. West winds around 15 mph. Highs 21°F to 27°F.

Monday Night: Mostly clear. Lows 3°F to 9°F.

Tuesday: Not as cold. Mostly sunny. Highs 30°F to 36°F.

Tuesday Night: Mostly clear in the evening then becoming partly cloudy. Lows 14°F to 20°F.

Wednesday: Mostly cloudy. Chance of snow in the morning...then chance of snow...possibly mixed with rain in the afternoon. Chance of precipitation 30 percent. Highs 32°F to 38°F.

Wednesday Night: Mostly cloudy with a 40 percent chance of snow. Lows 14°F to 20°F.

Thursday: Cloudy with a 40 percent chance of snow. Highs 26°F to 32°F.

Thursday Night: Cloudy with a 30 percent chance of snow. Lows 12°F to 18°F.

Friday: Cloudy in the morning then becoming partly cloudy. A 30 percent chance of snow. Highs 26°F to 32°F.

 Hazardous Weather Forecast  Yellowstone & Grand Teton Forecasts  Gibbon Falls Forecast  Mammoth Forecast  Midway Forecast  Norris Forecast  Old Faithful Forecast 

Mountain Weather

Yesterday about an inch of snow fell near Cooke City and West Yellowstone. This morning temperatures were in the high 20s Fahrenheit with winds blowing 15 mph from the West and gusting to 20 mph. Yesterday in the mountains near Bozeman, winds were blowing 20 to 40 mph. Today will be a mix of clouds and sun. High temperatures will be in the 30s Fahrenheit and may reach the 40s in places. Winds will increase slightly and shift to the Southwest bringing snow tonight. By Sunday morning several inches will have fallen with more to come throughout the day.

Snowpack and Avalanche Discussion:

Bridger, Gallatin, and Madison Ranges, Lionhead Area near West Yellowstone, and Cooke City:

Stability is neither really good nor really bad. The reason for heightened avalanche conditions in some terrain is the presence of faceted layers in the upper 3 feet of the snowpack. Also, recent strong winds, especially in the Bridger Range, formed fresh wind slabs. Warm temperatures will help these wind slabs stabilize and make them more difficult to trigger.

• Yesterday my partner and I found four different faceted layers in the snowpack in the northern Bridger Range (profile). We generally felt safe skiing steep terrain in the trees but with these layers lurking beneath our feet we carefully assessed each slope. With avalanches the snowpack should be assumed guilty until proven innocent.


• We also investigated a cornice triggered avalanche on Hardscrabble Peak (photo). It broke on very weak facets on a rocky bed surface and produced a massive pile of debris.


• Near Hebgen Lake north of West Yellowstone this week, skiers found weak facets about 2.5 feet deep breaking cleanly and propagating fractures in stability tests. They opted to ski low angle slopes.


• Also this week, Doug and Karl found plenty of weak facets on Mount Ellis. These facets also propagated fractures near the ridgetop where winds had deposited snow but did not propagate in the burned area with no wind-blown snow.

The reason conditions are not really bad is that regular and light snowfall has gradually buried these faceted layers without stressing them too much. However, snowfall this Sunday could push them closer to their breaking point. Stable slopes definitely exist as skiers found in the upper bowls of Hyalite on Thursday, but recent avalanches continue to remind us that unstable slopes also exist.

What to do? Dig about 3 feet deep in several different places and conduct several stability tests. Be especially wary of any snowpack with a total depth of 3 to 4 feet (about a ski pole length). In these places very weak facets usually exist near the ground and could produce an avalanche like one Eric and I investigated on Thursday (photo) on Mount Wheeler. Lastly, look for fresh wind slabs and don't trust them. Today human triggered avalanches remain possible and the Avalanche Danger is rated MODERATE.

The next advisory tomorrow morning at 7:30 AM. 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), (snowpits), or (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.