Today...Windy. Mostly cloudy. Slight chance of snow in the morning...then chance of snow in the afternoon. Highs 26°F to 32°F. Southwest winds 20 to 30 mph. Chance of snow 50 percent.

Tonight...Breezy. Snow likely in the evening...then snow after midnight. Snow accumulation of 2 to 3 inches. Lows -2°F to 4°F. West winds 15 to 25 mph until early morning. Chance of snow 80 percent.

Monday / Martin Luther King Jr Day...Colder. Snow in the morning...then snow likely in the afternoon. Snow accumulation of 1 to 2 inches. Total snow accumulation 3 to 5 inches. Highs 7°F to 13°F. West winds around 15 mph in the afternoon. Chance of snow 80 percent.

Monday Night / Martin Luther King Jr Night...Breezy. Cloudy with a 20 percent chance of snow. Lows -6°F to 0°F. Southwest winds 15 to 20 mph. Wind chill readings -18°F to -28°F.

Tuesday...Breezy. Mostly cloudy with a 50 percent chance of snow. Highs 10°F to 16°F. Southwest winds 15 to 25 mph. Lowest wind chill readings -20°F to -30°F in the morning.

Tuesday Night...Breezy. Cloudy with a 50 percent chance of snow. Lows 0°F to 6°F. Wind chill readings -17°F to -27°F.

Wednesday...Breezy. Not as cold. Snow likely in the morning...then snow in the afternoon. Moderate snow accumulations. Highs 18°F to 24°F. Chance of snow 80 percent. Lowest wind chill readings -21°F to -31°F in the morning.

Wednesday Night...Breezy. Not as cold. Snow likely. Moderate snow accumulations. Lows 14°F to 20°F. Chance of snow 70 percent.

Thursday...Breezy. Not as cold. Snow likely. Highs 26°F to 32°F. Chance of snow 70 percent.

Thursday Night...Breezy. Snow likely. Lows 14°F to 20°F. Chance of snow 60 percent.

Friday...Breezy. Cloudy with a 50 percent chance of snow. Highs 24°F to 30°F.

Friday Night...Breezy. Cloudy with a 50 percent chance of snow. Lows 14°F to 20°F.

Saturday...Breezy. Cloudy with a 50 percent chance of snow. Highs 25°F to 3°F1.

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

Mountain Weather

Warm and windy conditions are currently in place ahead of an approaching cold front. At 4:00 am this morning winds are blowing steady at 25-35 mph out of the West-northwest with gusts reaching into the 50s Fahrenheit. Mountain temperatures are in the mid to high 20s Fahrenheit under mostly clear skies with the exception of Cooke City where a 1 to 2 inches of snow has fallen overnight. A significant change in weather will take place as the day progresses. A cold front will arrive by early afternoon creating mostly cloudy skies, falling temperatures and an increasing chance of snow showers. By tomorrow morning temperatures will be in the single digits Fahrenheit and 2 to 4 inches will likely accumulate in the mountains.

Snowpack and Avalanche Discussion:

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

Today, triggering an avalanche will be like the Giants beating the Packers – it's not highly likely but it is possible. Can you put a number – 1 in 10, 1 in 100, 1 in 1000 – on your odds of triggering a slide? No. But there are a few simple decisions that can be made to help stack the odds in your favor and keep the chances of triggering a slide to a minimum.

1. Stay off slopes that have received wind deposited snow, most specifically, upper elevation slopes below ridelines or slopes on the leeward side of sub-ridges. These areas likely have a thick cohesive slab resting over weak faceted snow. These wind slabs, whether new or old, can propagate a fracture and produce an avalanche.

2. Avoid slopes steeper than 35 degrees. While steep slopes offer some of the best riding opportunities, they are also the most likely to produce and avalanche.

3. Carefully evaluate shallow and rocky terrain. These areas usually have variable snow depths, wind slabs and lots of potential trigger points.

One factor that makes stability assessment difficult is conditions vary widely from slope to slope. Yesterday, Mark and I rode into Cabin Creek and Tepee Basin in the southern Madison Range. We received unstable results during stability tests on one slope, while another appeared to be more stable. I found similar conditions around Buck Ridge on Friday. Also, skiers outside of Cooke City triggered a small side on a Southeast facing slope and reported cracking and collapsing yesterday, obvious signs of instability.

Hyalite Canyon deserves special mention because it has more stable conditions than other areas. However, recent wind slabs and a layer of near-surface facets 2 feet below the surface could produce avalanches under the weight of a skier or rider.

Although the odds of triggering an avalanche have decreased over time, the weak structure of the snowpack continues to make human trigged avalanches possible. For this reason 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.