Caution advised for snow falling off of building roofs. Park accordingly.

Dangerous avalanche conditions may already exist in many back country areas, please call the Recorded Avalanche Advisory 406-587-6981 for the most current conditions. Also, see the Avalanche Advisory posted below.

Today: Mostly cloudy. Patchy fog in the morning. Isolated snow showers in the afternoon. Chance of snow 20 percent. Highs 18°F to 24°F. Lowest wind chill readings -15°F to -25°F in the morning.

Tonight: Mostly cloudy with a 30 percent chance of snow. Lows 1°F to 7°F.

Wednesday: Breezy. Cloudy with a 50 percent chance of snow. West winds 15 to 20 mph in the afternoon. Highs 22°F to 28°F.

Wednesday Night: Cloudy with a 40 percent chance of snow. West winds around 15 mph in the evening. Lows 9°F to 15°F.

Thursday: Cloudy with a 50 percent chance of snow. Highs 19°F to 25°F.

Thursday Night: Mostly cloudy with a 20 percent chance of snow. Lows 4°F to 10°F.

Friday: Partly cloudy with a 20 percent chance of snow. Highs 23°F to 29°F.

Friday Night: Partly cloudy. Lows 6°F to 12°F.

Saturday: Mostly sunny in the morning then becoming partly cloudy. Highs 26°F to 32°F.

Saturday Night: Partly cloudy with a 20 percent chance of snow. Lows 10°F to 16°F.

Sunday: Mostly cloudy with a 40 percent chance of snow. Highs 24°F to 30°F.

Sunday Night: Mostly cloudy with a 30 percent chance of snow. Lows 4°F to 10°F.

Monday / Presidents' Day: Partly cloudy. Highs 17°F to 23°F.

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Mountain Weather

Last night a trace to one inch of snow fell in the southern mountains. Currently, westerly winds are blowing 10 to 20 mph except in the Bridger Range and Hyalite where they are reading 30 to 40 mph. Temperatures are near 10 degrees Fahrenheit under partly cloudy skies. Today will be partly to mostly cloudy with winds increasing out of the west to northwest. A trace to one inch may fall later tonight.

Snowpack and Avalanche Discussion:

Cooke City:

Cooke City is loving life: deep snow and mostly stable conditions. This could change if winds increase and build slabs, but for the moment the place you may find unstable snow would be on lower elevation slopes that have thin snow cover (video). For today, the Avalanche Danger remains LOW.

Southern Gallatin and Madison Ranges, Lionhead area near West Yellowstone:

Without new snow or wind-loading the avalanche danger from Big Sky to West Yellowstone is slowly improving, but getting trickier to assess. There are two problems buried in the snow. The first problem is on slopes with a thinner snowpack (about three feet thick or less) where 2/3 of it is facets. Eric and I toured in Beehive Basin yesterday and confirmed this. Other skiers around Big Sky on Sunday and Monday also got collapsing and cracking and triggered a small pocket on a thin, west facing slope (photo). Yesterday on Lionhead Ridge outside of West Yellowstone skiers triggered a thinly covered slope that had a wind-slab on it (photo). Many slopes do not have these instabilities and will not crack or "whumph". In the absence of obvious warning signs, the first line of defense should be a quick probe to feel for a thin snow depth—thin is bad.

The second problem is confined to the southern Madison Range and Lionhead area. A layer of surface hoar and/or small facets are buried 1 to 2 feet deep. These are gaining strength, but can still avalanche. Luckily they are easy to spot as a dark stripe in a snowpit. These are worth digging for and testing. To be conservative I recommend skiing or sledding elsewhere if you find them.

For today, the Avalanche Danger is rated MODERATE on all slopes since human triggered avalanches are still possible.

Bridger Range, and Northern Gallatin Range:

Strong winds in the Bridger and northern Gallatin Ranges are scouring some slopes and loading others. The Hyalite area has a foot of snow that fell early Sunday morning which is now blowing around. On Saturday evening skiers triggered an avalanche on Alex Lowe Peak, located southwest of Mount Blackmore. The snowpack was thin, weak and capped with a dense wind slab. The price they paid was only a lost ski and a cold bivouac. Separately, avalanches can be expected where the snowpack is thin and also on wind-loaded slopes, but combined these create especially worrisome conditions. Although the Bridger Range did not get the snow that Hyalite did, their downhill winds are especially strong and scouring the alpine regions while loading slopes and gullies at mid-elevations. Today the Avalanche Danger is rated CONSIDERABLE on all wind-loaded terrain. All other slopes have a MODERATE Avalanche Danger.

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, PHOTOS, SNOWPITS, and VIDEOS

1. For links to Articles, Education and (photos), (snowpits), or (videos) listed in the above report, please visit this Link.

2. They have recently uploaded more photos and snowpits to their web site, more than what are linked in the advisory above.

3. They have creating a series of "How To…" stability test videos. So far they have clips on performing a CT and ECT. They are located under Stability Tests on their Resources page.

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.