Today...Partly cloudy. Highs 21°F to 27°F. Southwest winds around 15 mph late in the afternoon.

Tonight...Breezy. Mostly cloudy. Slight chance of snow in the evening...then chance of snow after midnight. Lows 10°F to 16°F. Southwest winds 15 to 20 mph. Gusts up to 35 mph. Chance of snow 40 percent.

Wednesday...Breezy. Snow likely. Snow accumulation of 1 to 2 inches. Highs 26°F to 32°F. Southwest winds 15 to 20 mph with gusts to around 35 mph. Chance of snow 70 percent.

Wednesday Night...Breezy. Snow likely. Snow accumulation of 1 to 2 inches. Lows 17°F to 23°F. Southwest winds 15 to 20 mph. Chance of snow 70 percent.

Thursday...Breezy. Snow likely. Snow accumulation of 2 to 4 inches. Total snow accumulation 4 to 8 inches. Highs 27°F to 33°F. Southwest winds 15 to 20 mph. Chance of snow 70 percent.

Thursday Night...Colder...cloudy. Chance of snow in the evening... Then slight chance of snow after midnight. Lows 7°F to 13°F. Chance of snow 40 percent.

Friday...Mostly cloudy in the morning then clearing. Highs 19°F to 25°F.

Friday Night...Mostly clear. Lows 1°F to 7°F.

Saturday...Partly cloudy. Highs 20°F to 26°F.

Saturday Night...Partly cloudy with a 20 percent chance of snow. Lows 6°F to 12°F.

Sunday...Mostly cloudy with a 30 percent chance of snow. Highs 26°F to 32°F.

Sunday Night...Mostly cloudy in the evening then becoming partly cloudy. A 20 percent chance of snow. Lows 8°F to 14°F.

Monday...Mostly cloudy with a 30 percent chance of snow. Highs 26°F to 32°F.

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Mountain Weather

Snowfall yesterday afternoon dropped six inches around Big Sky and 2 to 3 inches everywhere else. Ridgetop winds have been blowing west to northwest at 15-20 mph with gusts to 30 mph. Mountain temperatures are in the single digits Fahrenheit under clear skies. Today will be sunny, but cloud up later this afternoon as winds increase to 20-30 mph from the southwest. Temperatures will warm into the 20s Fahrenheit this afternoon and drop to the teens Fahrenheit tonight. By morning 1 to 2 inches will fall in the southern mountains with scattered and more widespread showers expected through Wednesday.

Snowpack and Avalanche Discussion:

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

Even though the weekend avalanche warning in the southern mountains expired, this area still remains quite active. Outside Cooke City yesterday a snowmobiler was buried in an avalanche on Scotch Bonnet near Lulu Pass. Luckily his arm was sticking out of the snow and nearby skiers dug him out. This near miss is just one of a string. On Saturday, a massive slide on Scotch Bonnet was triggered from hundreds of feet away and later that same day a snowmobiler was partially buried on Henderson Mountain in an avalanche he triggered and was unable to outrun. Mark was there and posted a video and picture of the activity. On Sunday, a snowboarder triggered a slide near Lulu pass on a south facing slope and released another slide sympathetically. A layer of small-grained facets buried under four feet of new snow since last Monday (5 inches SWE) is the unstable weak layer.

In Lionhead on Sunday, there were multiple avalanches remotely triggered by snowmobilers. One notable slide broke on a low angle 30 degree slope from 300 feet away. Yesterday, another natural avalanche was seen in Cabin Creek by Ace Powder Guides. Weak, large-grained sugary snow is breaking a foot or two off the ground from the recent snows.

The avalanche warning this weekend denoted hair-trigger conditions with many avalanches releasing naturally or being triggered from afar. Things have improved since then, but only slightly. Touchy, dangerous conditions still exist in the southern mountains. A few inches of new snow with winds will keep the backcountry dangerous. For today, the Avalanche Danger is rated HIGH on all wind-loaded slopes and CONSIDERABLE elsewhere. Unfortunately, around Cooke City the more popular lines to ride or ski are usually wind-loaded.

The Bridger and northern Madison Ranges:

In the Bridger Range a couple inches of new snow with westerly winds blowing 20-30 mph is enough to keep the weak layers in the snowpack under stress. A foot of new snow by Sunday morning broke avalanches loose in the Frazier/Fairy Lake area. The snow structure is weak and stability on wind-loaded slopes is suspect. Eric and his partner skied into the Throne area on Sunday. He turned around and retreated as the slope steepened, a telling sign as any stability test.

In the last 24 hours the mountains around Big Sky got six inches of snow with wind. I dug four snowpits in the Beehive/Bear Basin area on Sunday and found a snowpack that was strengthening, but not quite healed. As my video shows, the facets near the ground still break on facets and depth hoar.

For today, the Avalanche Danger is CONSIDERABLE on all wind-loaded slopes and MODERATE elsewhere.

The northern Gallatin Range:

During the last five days the northern Gallatin Range has picked up only five inches of snow, not enough to bump the danger upward. The snowpack is generally strong in the Hyalite area with weaker snows found around Mount Ellis and Little Bear. Yesterday, a snowboarder on Mount Ellis found facets in the lower half of the snowpack capped by a wind slab at the higher elevation. He descended a conservative line. Since avalanches are still possible, the Avalanche Danger is rated MODERATE.

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 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!

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.