Rest Of Today...Mostly cloudy. Chance of snow in the morning...then slight chance of snow in the afternoon. Chance of snow 40 percent. Highs 21°F to 27°F.

Tonight...Mostly cloudy in the evening then becoming partly cloudy. A 20 percent chance of snow. Patchy fog after midnight. Lows -2°F to 6°F.

Thursday...Mostly cloudy. Patchy fog in the morning. Occasional flurries through the day. Highs 22°F to 28°F.

Thursday Night...Cloudy with a 50 percent chance of snow. Lows 6°F to 12°F.

Friday...Mostly cloudy with a 30 percent chance of snow. Highs 26°F to 32°F.

Friday Night...Mostly cloudy. Slight chance of snow in the evening...then occasional flurries after midnight. Patchy fog after midnight. Chance of snow 20 percent. Lows 10°F to 16°F.

Saturday...Mostly cloudy with a 50 percent chance of snow. Highs 27°F to 33°F.

Saturday Night...Cloudy with a 50 percent chance of snow. Lows 7°F to 13°F.

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

Sunday Night...Mostly cloudy with a 30 percent chance of snow. Lows 1°F to 7°F.

Monday - Washingtons Birthday...Mostly cloudy with a 40 percent chance of snow. Highs 19°F to 25°F.

Monday Night...Mostly cloudy with a 40 percent chance of snow. Lows 5°F to 11°F.

Tuesday...Mostly cloudy with a 40 percent chance of snow. Highs 22°F to 28°F.

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

Mountain Weather

Before the storm ended yesterday morning an additional inch of snow fell in most locations. Winds blew westerly at 15-20 mph yesterday, but have calmed to 10 mph. Today skies will be mostly sunny, although the mountains around West Yellowstone and Cooke City will remain cloudy for most of the morning. No snow is in the immediate forecast. This morning mountain temperatures are in the single digits Fahrenheit, but will warm to the upper teens Fahrenheit as winds remain eerily calm.

Snowpack and Avalanche Discussion:

The mountains around Cooke City:

Yesterday, the mountains around Cooke City received four inches by mid-morning. West winds moved a bit of snow and we got reports of a few natural slides on east-facing slopes. These slides, although small, were the second time avalanches occurred on these slopes. Repeat avalanches challenge the incorrect assumption that a slope is stable for the rest of the season once it slides.

Weak snow at the ground continues to get buried deeper making it more difficult to trigger. Another layer of weak snow formed at the surface during previous clear spells which is now buried under 1 to 2 feet of snow. Signs of instability will decrease quickly with our stable weather, but you'll still be able to trigger slides on a few slopes. For today, the Avalanche Danger is rated CONSIDERABLE on any slope that was wind-loaded yesterday. All other slopes have a MODERATE Avalanche Danger.

The southern Madison and southern Gallatin Ranges and the Lionhead area near West Yellowstone:

The southern mountains got three inches of light powder yesterday. Although the snowpack is very weak it will support this new snow, especially since wind-loading is minimal. Yesterday, skiers on Bacon Rind found even better stability than their trip a week ago. The weak, faceted snowpack in these mountains will have good stability until they get a substantial snowfall. If you look at the layers in Eric's snowpit from Sunday and imagine they are children's building blocks, it's easy to see how they would topple. For today, it's still not out of the question to trigger avalanches and the Avalanche Danger is rated MODERATE.

The Bridger, northern Madison and northern Gallatin Ranges:

Yesterday, on his day off, Eric went to Mount Ellis and reported good stability and skiing on four inches of new snow. I toured into Beehive and Bear Basins and found plenty of facets and good stability. In an east-facing snowpit on the Bear Basin side I was able to get a layer of facets to propagate in my extended column test with a lot of whacks (23). On the Beehive side I dug into three feet of facets with a few ice crusts, but found good stability. Mark was in the Bridger Range on Friday and found a thin, weak snowpack. His snowpit showed depth hoar at the ground, near surface facets a few inches from the top, yet nothing was moving in his stability tests. He summed up his concerns in his video when his partner asks him, "So what's your point?" and he answers, "We're just going to have to wait and see what happens". This recent storm was not enough to make anything "happen". For today, the Avalanche Danger is rated MODERATE on slopes steeper than 35 degrees and there is a LOW Avalanche Danger on all other terrain.

NRCS Snowpack Summary Graphs:

For the current state of our snowpack depth (about 70% of average on the Gallatin), check out these two graphs generated by NRCS (graph 1, graph 2).

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.

Beacon Parks

The Friends of the Avalanche Center installed a Beacon Training Park outside West Yellowstone. It's located south of town on the main snowmobile trail. Stop by and do a quick practice before heading off into the mountains!

EDUCATION, EVENTS, PHOTOS, SNOWPITS, and VIDEOS

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

2. 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.

3. Check out all our education programs, Click Here.

Information provided by Doug Chabot, Mark Staples, and Eric Knoff from the Gallatin National Forest Avalanche Center. For Events and Education, or 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.