Rest Of Today...Breezy. Mostly cloudy. Chance of rain and snow in the afternoon. Highs 39°F to 45°F. Southwest winds 15 to 25 mph. Chance of precipitation 40 percent.

Tonight...Windy...snow. Snow accumulation of 5 to 8 inches. Lows 14°F to 20°F. Southwest winds 20 to 30 mph shifting to the west 15 to 20 mph early in the morning. Gusts up to 45 mph in the evening. Chance of snow near 100 percent.

Friday...Breezy...colder...cloudy. Snow in the morning...then scattered snow showers in the afternoon. Snow accumulation up to 1 inch. Total snow accumulation 5 to 9 inches. Highs 25°F to 31°F. West winds 15 to 20 mph. Chance of snow 80 percent.

Friday Night...Mostly cloudy. Lows 10°F to 16°F. Southwest winds around 15 mph in the evening.

Saturday...Cloudy. Chance of snow in the morning...then snow likely and chance of rain in the afternoon. Snow accumulation of 1 to 2 inches. Highs 31°F to 37°F. Chance of precipitation 70 percent.

Saturday Night...Cloudy with a 50 percent chance of snow. Lows 16°F to 22°F.

Sunday...Mostly cloudy with slight chance of snow in the morning... Then partly cloudy with slight chance of rain and snow in the afternoon. Highs 32°F to 38°F. Chance of precipitation 20 percent.

Sunday Night...Mostly cloudy with a 20 percent chance of snow. Lows 17°F to 23°F.

Monday...Mostly cloudy. Chance of snow in the morning...then chance of snow and rain in the afternoon. Highs 33°F to 39°F. Chance of precipitation 50 percent.

Monday Night...Mostly cloudy with a 50 percent chance of snow. Lows 15°F to 21°F.

Tuesday...Mostly cloudy with a 20 percent chance of snow. Highs 31°F to 37°F.

Tuesday Night...Mostly cloudy with a 30 percent chance of snow. Lows 11°F to 17°F.

Wednesday...Breezy. Mostly cloudy. Chance of snow in the morning... Then chance of snow and rain in the afternoon. Highs 34°F to 40°F. Chance of precipitation 40 percent.

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

Mountain Weather

Since yesterday 2 to 3 inches of snow fell in the mountains near Cooke City, West Yellowstone, and the Taylor Fork drainage. Winds will dominate today's weather. They increased last night and were blowing 20-40 mph from the Southwest this morning. Today winds will increase with gusts reaching 50 mph. Temperatures were in the mid 20s Fahrenheit this morning and should climb into the mid 30s Fahrenheit today. A Pacific storm driving these winds will bring more snow starting this evening and ending tomorrow morning. 5 to 7 inches should fall near Cooke City and West Yellowstone, 3 to 5 inches near Big Sky, and 2 to 3 inches near Bozeman.

Snowpack and Avalanche Discussion:

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

Watch for wind loaded slopes from strong Southwest winds today. Although winds have moved most of the available snow, increased winds will find more to move and last night's storm provided more snow for transport. The good news is that local ski patrols have not reported any significant avalanche activity with these fresh wind slabs. Most of their avalanche activity has been small and easily mitigated. With increased winds, it will be easy to trigger a fresh wind slab in steep terrain today. Wind slabs on slopes less than 35 degrees should be a bit more stubborn.

A secondary concern is a layer of small facets. In most places this layer does not exists or is not a concern. It can be found near an ice crust mostly on slopes with some exposure to the sun, and this layer needs a wind load to cause an avalanche. An avalanche from last weekend (crown, snowpack) is a good example. This is a tricky problem found on isolated slopes where tug of war occurs. Solar radiation helps form near-surface facets, but the warmth also helps surface layers of snow bond to each other. Most slopes do not have the unique combination of these variables to be unstable but a few do.

Many small human triggered avalanches are likely on steep slopes with a wind load. Look for soft snow unaffected by the wind and you will generally find stable conditions. Today the avalanche danger is:

CONSIDERABLE Avalanche Danger on wind loaded slopes > 35 degrees.

MODERATE Avalanche Danger on wind loaded slopes < 35 degrees.

LOW Avalanche Danger on slopes without a wind load.

PHOTOS, SNOWPITS, VIDEO and SURVEY RESULTS

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. The results from our survey are posted online. Thanks to all who participated. You can check out the results at http://bit.ly/fpLuSi.

In response to our survey we added a new page to the website with images of our snowpit profiles. This page is under the Resources/Other Info tab at http://fsavalanche.org/Encyclopedia/snowpit.htm

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