Early This Morning...Mostly cloudy. Lows -5°F to 5°F. Southwest winds around 15 mph with gusts to around 35 mph.

Today...Partly cloudy in the morning then becoming mostly cloudy. Highs 19°F to 25°F. Southwest winds around 15 mph. Lowest wind chill readings -15°F to -25°F in the morning.

Tonight...Partly cloudy. Lows 0°F to 10°F. Southwest winds around 15 mph.

Saturday...Breezy. Partly cloudy. Highs 22°F to 28°F. Southwest winds 15 to 20 mph.

Saturday Night...Breezy. Partly cloudy. Lows 8°F to 14°F. Southwest winds 15 to 20 mph.

Sunday...Breezy. Mostly cloudy. Chance of snow in the afternoon. Highs 23°F to 29°F. Southwest winds 15 to 25 mph. Chance of snow 40 percent.

Sunday Night...Colder. Snow likely in the evening...then chance of snow after midnight. Light snow accumulations. Lows 0°F to 6°F. Chance of snow 60 percent. Wind chill readings -10°F to -20°F.

Monday / Martin Luther King Jr Day...Colder. Cloudy with a 50 percent chance of snow. Highs 7°F to 13°F. Wind chill readings -11°F to -21°F.

Monday Night / Martin Luther King Jr Day...Colder. Mostly cloudy with a 20 percent chance of snow. Lows -4°F below to -10°F.

Tuesday...Cloudy with a 40 percent chance of snow. Highs 10°F to 18°F.

Tuesday Night...Cloudy with a 50 percent chance of snow. Lows -1°F to 7°F.

Wednesday...Windy. Not as cold. Cloudy with a 50 percent chance of snow. Highs 21°F to 27°F.

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

Thursday...Breezy. Cloudy with a 50 percent chance of snow. Highs 25°F to 31°F.

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Mountain Weather

This morning mountain temperatures were in the mid teens Fahrenheit except near West Yellowstone and Cooke City where temperatures were in the single digits Fahrenheit. Ridgetop winds were blowing 5-15 mph mostly from the West with gusts of 25-35 mph. Over the Bridger Range and Hyalite winds were blowing stronger at 25-40 mph. Today will be similar to yesterday. Under mostly sunny skies temperatures will warm into the mid 20s Fahrenheit. Winds shouldn't change much and remain westerly blowing 10-15 mph with gusts of 20-30 mph. Weather models continue to show the current ridge of high pressure flattening on Sunday followed by a trough of low pressure approaching Southwest Montana. This trough will bring cold temperatures and some precipitation.

Snowpack and Avalanche Discussion:

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

Unfortunately there is never a point when conditions switch from unstable to stable. Instead, the odds of triggering an avalanche simply decrease. Almost 2 weeks ago, following the New Year's Eve storm, all slopes were unstable and obvious signs on instability, like recent avalanches and collapsing and cracking, were widespread for at least a week after this storm. Signs of instability have become more isolated. Yesterday near Cooke City, skiers experienced two collapses during a long tour.

The reason signs of instability continued for so long is that snowpack structure is bad. In most cases a slab 1 to 2 feet thick rest on a variety of weak layers of faceted snow. This slab is supportable and if you don't get off your sled or step out of your skis, it will be hard to tell what's under it. Conditions might "feel good" when they are not. In some places like Mount Ellis there is a layer of buried surface hoar. On some South facing slopes, there are weak facets next to an ice crust. Two experienced skiers found this layer in Hyalite Canyon just as Doug did earlier this week. I found a similar layer near Cooke City on Wednesday. On other slopes the snowpack is relatively shallow and has big, obvious depth hoar crystals under the supportable slab.

There are a few ways to reduce the odds of triggering an avalanche:

• Manage slope angles. With each degree of steepness over 30 degrees the odds of triggering an avalanche increase.

• Avoid fresh wind slabs and drifts. The combination of wind and new snow Tuesday night loaded isolated slopes. Snowmobilers near Cooke City triggered a few small, slab avalanches in the new snow yesterday. Triggering small avalanches can sometimes trigger larger avalanches. Check out Karl's explanation of the difference between a wind loaded and non wind loaded slope.

• Avoid steep rocky, terrain where snowpack depth is more variable and wind loading is more likely. These highly variable areas increase the odds you will find the trigger point for an avalanche.

While the odds of triggering an avalanche have slowly decreased, variability has increased. This variability means some slopes are more prone to producing avalanches than others. For this reason each slope deserves a careful evaluation of snow and terrain. Today the Avalanche Danger is rated MODERATE.

Beacon Parks

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

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, 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.