Today...Mostly cloudy with a 40 percent chance of snow. Highs 25°F to 31°F.

Tonight...Mostly cloudy. Slight chance of snow in the evening... Then occasional flurries after midnight. Patchy fog after midnight. Chance of snow 20 percent. Lows 4°F to 10°F.

Saturday...Patchy fog in the morning. Mostly cloudy with a 50 percent chance of snow. Southwest winds around 15 mph in the late morning and afternoon. Highs 26°F to 32°F.

Saturday Night...Snow likely. Snow accumulation of 2 to 3 inches. Southwest winds around 15 mph. Chance of snow 70 percent. Lows 8°F to 14°F.

Sunday...Chance of snow in the morning...then snow likely in the afternoon. Snow accumulation of 1 to 2 inches. Total snow accumulation 3 to 5 inches. Southwest winds around 15 mph in the afternoon. Chance of snow 70 percent. Highs 20°F to 26°F.

Sunday Night...Colder. Mostly cloudy with chance of snow in the evening...then partly cloudy with slight chance of snow after midnight. Chance of snow 40 percent. Lows 1°F to 7°F.

Monday - Washingtons Birthday...Partly cloudy. Slight chance of snow in the morning...then slight chance of snow showers in the afternoon. Chance of snow 20 percent. Highs 21°F to 27°F.

Monday Night...Partly cloudy with a 20 percent chance of snow. Lows 5°F to 11°F.

Tuesday...Mostly cloudy with a 40 percent chance of snow. Highs 24°F to 30°F.

Tuesday Night...Mostly cloudy with a 50 percent chance of snow. Lows 11°F to 17°F.

Wednesday...Mostly cloudy with a 50 percent chance of snow. Highs 26°F to 32°F.

Wednesday Night...Mostly cloudy with a 40 percent chance of snow. Lows 10°F to 16°F.

Thursday...Mostly cloudy with a 40 percent chance of snow. Highs 24°F to 30°F.

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

Mountain Weather

Overnight 2 to 3 inches of snow fell throughout the advisory area. Winds decreased slightly from yesterday and this morning were blowing 10 mph with gusts of 25 mph from the West except in the Bridger Range where winds were blowing 20 and gusting to 30. Temperatures were in the low to mid teens Fahrenheit. Snow will continue this morning with an additional 2 to 3 inches falling. Some areas may see some sun this afternoon before another small dose of snow arrives Saturday. Temperatures will rise into the low 20s Fahrenheit, and winds will decrease a little by afternoon.

Snowpack and Avalanche Discussion:

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

New snow fell on 5 of the last 7 days. This snow by itself has not been enough to change the avalanche danger much since it has slowly accumulated, and riding conditions have improved. More importantly, however, this snowfall provided ammunition for increased winds to build many fresh wind slabs.

• Skiers on Saddle Peak yesterday reported heavy wind loading and many small slab avalanches.

• A regular skier in Hyalite found many fresh wind slabs that readily cracked and slid while others did not. He also observed more natural avalanches yesterday than any other of the 50 days he's skied there this season.

• Karl, Doug, and I skied in Hyalite yesterday. Unfortunately wind slabs and drifts did not crack or produce avalanches for us, but they should not be trusted. One may not avalanche while another will. The good news is that winds did not form wind slabs very far below ridgelines and lots of good powder could be found.

• Ski Patrollers at Big Sky triggered wind slabs that formed early yesterday morning.

• Natural avalanches occurred near Cooke City during recent days with calm winds. With increased winds more will certainly occur.

Now is a tricky time because deeper instabilities and larger avalanches could start occurring. In the current weather pattern with small incremental loads, it is hard to say exactly when these large avalanches will occur, but we know this point is not far away. Throughout the advisory area, the structure of the snowpack is bad. It has depth hoar and other faceted crystals in the lower half of the snowpack covered by a cohesive slab. Hyalite Canyon is the exception. There are some faceted layers in the snowpack but they are much stronger there than in other areas.

The primary concern is fresh wind slabs. A secondary concern is avalanches breaking on deeper layers in the snowpack or at the ground. These would most likely occur on the same slopes where fresh wind slabs exist. Today, all wind loaded slopes have a CONSIDERABLE Avalanche Danger. Non wind loaded slopes have a MODERATE Avalanche Danger.

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.