Rest Of Today...Windy...snow. New snow accumulation of 2 to 3 inches. Highs 31°F to 37°F. Southwest winds 20 to 30 mph with gusts to around 45 mph decreasing to 15 to 20 mph with gusts to around 35 mph in the afternoon. Chance of snow near 100 percent.

Tonight...Breezy. Snow in the evening...then snow likely after midnight. Snow accumulation of 2 to 3 inches. Total snow accumulation 4 to 11 inches. Lows 14°F to 20°F. Southwest winds 15 to 20 mph. Chance of snow 90 percent.

Thursday...Cloudy with a 50 percent chance of snow. Highs 27°F to 33°F. Southwest winds around 15 mph.

Thursday Night...Mostly cloudy with a 30 percent chance of snow. Lows 10°F to 16°F. Southwest winds around 15 mph.

Friday...Partly cloudy with isolated snow showers. Highs 29°F to 35°F. Chance of snow 20 percent.

Friday Night...Mostly cloudy with a 20 percent chance of snow. Lows 15°F to 21°F.

Saturday...Mostly cloudy. Chance of snow showers in the morning... Then chance of snow showers and rain showers in the afternoon. Highs 31°F to 37°F. Chance of precipitation 40 percent.

Saturday Night...Mostly cloudy with a 40 percent chance of snow showers. Lows 13°F to 19°F.

Sunday...Mostly cloudy. Chance of snow showers in the morning... Then chance of snow showers and rain showers in the afternoon. Highs 31°F to 37°F. Chance of precipitation 40 percent.

Sunday Night...Mostly cloudy in the evening then becoming partly cloudy. A 20 percent chance of snow showers. Lows 12°F to 18°F.

Monday...Partly cloudy with slight chance of snow showers in the morning...then mostly cloudy with slight chance of snow showers and rain showers in the afternoon. Highs 32°F to 38°F. Chance of precipitation 20 percent.

Monday Night...Mostly cloudy with a 30 percent chance of snow showers. Lows 14°F to 20°F.

Tuesday...Mostly cloudy. Chance of snow showers in the morning... Then chance of snow showers and rain showers in the afternoon. Highs 32°F to 38°F. Chance of precipitation 40 percent.

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Mountain Weather

In the last 24 hours 16 inches of snow has fallen in the southern Madison Range and a foot near Cooke City. Moonlight Basin received seven inches while two to three inches fell in Hyalite and the Bridger Range. The storm is not done. Westerly winds are averaging 20-30 mph with gusts hitting 60 mph. Mountain temperatures are in the high 20s Fahrenheit. Today I expect 8 to 12 inches in the southern mountains and 4 to 6 inches in the northern ranges as winds slightly abate and temperatures drop into the low 20s Fahrenheit.

Snowpack and Avalanche Discussion:

The Bridger, the northern Madison and northern Gallatin Ranges:

Snowfall in the north has been sporadic. At 6:00 a.m. seven inches has fallen around Lone Peak while the mountains around Bozeman got two to three inches so far. The wind was not so discretionary. It's blowing strong everywhere. It's quite possible to find natural avalanche activity today and I feel confident a skier or snowmobiler could trigger wind drifts. Without buried weak layers, avalanche activity will be confined to the last few days' new snow.

More snowfall and strong winds today are creating a CONSIDERABLE Avalanche Danger on all wind-loaded slopes and a MODERATE Avalanche Danger elsewhere.

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

The southern mountains are getting fire hosed. Over two feet has fallen in 48 hours and it's still snowing. The snow is not light powder either—its 10 percent density cream. This snowfall measures two inches of snow water equivalency—a lot of stress to be added in such a short period of time. Eric found faceted layers around Bacon Rind and Teepee Creek which will be straining to support this new load. Mark rode around Cooke City yesterday and saw a large avalanche on Republic Peak (Photo), but no activity anywhere else. He also hunted for weak layers, but came up empty. Other than the facets Eric found, we have not seen widespread instabilities. The upper few feet of the snowpack is a hodgepodge of ball bearing graupel pellets, ice crusts underlying the new snow, and fluctuating densities in the storm snow. But the real driving force behind the rising avalanche danger is the heavy rate of snowfall and ripping winds. Large snow loads can stress even the strongest layers to their breaking point (Video).

With winds gusting to 60 mph, two feet of new snow and more falling every hour, slopes will be unstable today and have a CONSIDERABLE Avalanche Danger.

Cooke City, Montana Snowpack Video.

Avalanche Video Clip from Utah

http://youtu.be/1ynAm5Wao1I?hd=1

This is a great clip of a snowmobiler triggering a slide on March 9th in the Uinta Mountains, Utah. He hurt his leg, trashed his machine, but should recover fine. Watching the clip a few things stand out:

1. Small slopes can be dangerous, especially when slides push you into trees.

2. His helmet cam shows how fast even a small slide accelerates.

3. Partners watching from a safe zone are worth their weight in gold.

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.