Today...Cloudy with a 50 percent chance of snow. Highs 30°F to 36°F.

Tonight...Cloudy with a 40 percent chance of snow. Lows 10°F to 16°F.

Sunday...Mostly cloudy with a 50 percent chance of snow. Highs 28°F to 34°F.

Sunday Night...Cloudy with a 50 percent chance of snow. Lows 11°F to 17°F.

Monday...Mostly cloudy with a 30 percent chance of snow. Highs 25°F to 31°F.

Monday Night...Partly cloudy with a 20 percent chance of snow. Lows 7°F to 13°F.

Tuesday...Partly cloudy with a 20 percent chance of snow showers. Highs 25°F to 31°F.

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

Wednesday...Partly cloudy with a 20 percent chance of snow showers. Highs 23°F to 29°F.

Wednesday Night...Partly cloudy with a 20 percent chance of snow showers. Lows 4°F to 10°F.

Thursday...Partly cloudy with a 20 percent chance of snow showers. Highs 21°F to 27°F.

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

Friday...Partly cloudy with a 20 percent chance of snow showers. Highs 24°F to 30°F.

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

Mountain Weather

Since yesterday most areas received 4 to 6 inches of snow. Winds have been incredibly calm but, yesterday evening they blew westerly 15-20 mph with 30-40 mph gusts. This morning winds were blowing 5-10 mph mostly from the west except in the Bridger Range where cold east winds dropped temperatures into the single digits to teens Fahrenheit. In all other places this morning, temperatures were in the low-mid 20s Fahrenheit. There may be some flurries today but no accumulation. Very calm winds will continue and mostly cloudy skies should keep temperatures from rising more than a few degrees.

Snowpack and Avalanche Discussion:

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

Do not trust the snowpack. It produced several large avalanches about one week ago after receiving only a few inches of new snow. One massive avalanche occurred on Mount Abundance and another occurred on Lionhead. Another slide was seen on Thursday in Sheep Creek near Cooke City. Today's new snow may have added just enough weight, thus enough stress to produce more large avalanches. These can be triggered near the bottom of a slope as Eric found last weekend. He was surprised by this avalanche but wisely traveling in safe terrain just outside the runout zone. When experienced avalanche professionals get surprised, we should take note and be extra conservative in our decisions about where to ride.

Another concern is a layer of weak snow that formed on the snow surface last weekend during a period of clear, sunny weather. This layer formed on all aspects and will easily break just under the new snow mostly on slopes with wind deposited snow from last night's increased wind. The good news is that this weak layer will make the powder seem deeper than it is. For today, new snow has improved riding conditions but made avalanche conditions worse and the Avalanche Danger is CONSIDERABLE on all slopes.

The northern Madison, northern Gallatin, and Bridger Ranges:

Near Big Sky and Bozeman, the primary avalanche concern is a layer of near surface facets that formed last weekend and was buried yesterday. It exists on all aspects. Ski Patrollers at the Yellowstone Club took amazing photos of these small delicate crystals, and I found this layer in Hyalite on Tuesday and on Sacajawea Peak yesterday. Ski patrollers at Big Sky reported this layer to be very reactive yesterday afternoon near ridgelines. Westerly winds increased significantly last night easily transporting the new snow. Fresh wind slabs and drifts resting on this weak layer will easily produce avalanches today.

A secondary concern is faceted snow deeper in the snowpack. On Sacajawea Peak yesterday, my partner was shocked seeing weak depth hoar near the ground. As he isolated a column for a compression test, he said "I'm surprised this column is still standing." In fact it took lots of force to break the column (CT21 Q1, CT25 Q1) because the snowpack had no stress on it. With the new snow, it now has stress. A smaller avalanche breaking near the surface will add even more stress and big avalanches are a real possibility. One exception is Hyalite Canyon where the snowpack is generally much stronger and avalanches breaking deep in the snowpack are unlikely. For today, all wind loaded slopes have a CONSIDERABLE Avalanche Danger. Non wind loaded slopes have a MODERATE Avalanche Danger.

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

10th Annual King and Queen of the Ridge

The 10th Annual King and Queen of the Ridge Hike/Ski-a-thon fundraiser is Saturday, Feb 11th. The event supports avalanche education in southwest Montana. Collect pledges for one, two or the most Ridge hikes you can do in the five hours of competition. 100% of the proceeds go to the Friends of Gallatin National Forest Avalanche Center. Kids and families are encouraged to hike too! More Information / Registration Form.

You can help raise money two ways:

1). Get pledges and hike the ridge. You don't have to do 20 laps – you can get flat pledges and hike just once!

2). Sponsor someone. If you don't have someone to sponsor, consider sponsoring the GNFAC since we'll be hiking for dollars. Email us at mtavalanche@gmail.com with a pledge!

Go to http://bridgerbowl.com/events/view_event/81/ for more information and registration forms.

PRIZES INCLUDE: 4frnt skis, two pair of Schnee's Hunter boots, three Mystery Ranch backpacks and three pair of Oboz shoes.

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.