Today...Breezy...cloudy. Slight chance of snow in the morning... Then scattered snow showers and rain showers in the afternoon. Highs 32°F to 38°F. Southwest winds 15 to 20 mph. Chance of precipitation 40 percent.

Tonight...Breezy. Snow likely. Snow accumulation of 2 to 3 inches. Lows 19°F to 25°F. Southwest winds 15 to 20 mph. Chance of snow 60 percent.

Sunday...Mostly cloudy with a 20 percent chance of snow. Highs 36°F to 42°F. Southwest winds around 15 mph.

Sunday Night...Breezy. Cloudy with a 50 percent chance of snow. Lows 19°F to 25°F. South winds 15 to 20 mph.

Monday...Chance of snow in the morning...then snow and rain likely in the afternoon. Snow accumulation of 2 to 4 inches. Highs 36°F to 42°F. Southwest winds around 15 mph. Chance of precipitation 70 percent.

Monday Night...Breezy...cloudy. Snow likely in the evening...then chance of snow after midnight. Moderate snow accumulations. Lows 17°F to 23°F. Chance of snow 70 percent.

Tuesday...Mostly cloudy. Chance of snow in the morning...then chance of rain and snow in the afternoon. Highs 33°F to 39°F. Chance of precipitation 30 percent.

Tuesday Night...Mostly cloudy with a 50 percent chance of snow. Lows 18°F to 24°F.

Wednesday...Breezy. Snow likely in the morning...then snow and rain likely in the afternoon. Highs 33°F to 39°F. Chance of precipitation 60 percent.

Wednesday Night...Breezy. Cloudy with a 50 percent chance of snow. Lows 12°F to 18°F.

Thursday...Mostly cloudy with a 30 percent chance of snow. Highs 29°F to 35°F.

Thursday Night...Mostly cloudy with a 20 percent chance of snow. Lows 12°F to 18°F.

Friday...Mostly cloudy. Slight chance of snow in the morning...then slight chance of rain and snow in the afternoon. Highs 32°F to 38°F. Chance of precipitation 20 percent.

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

Mountain Weather

Overnight a trace to one inch of snow fell over much of our forecast area. Currently, winds are blowing out of the Westsouthwest at 5-15 mph and mountain temperatures are in the high single digits to low teens Fahrenheit. Today, mountain temperatures will warm into the high 20's to low 30's Fahrenheit and winds will stay light out of the Westsouthwest at 5-15 mph. Skies will be partly cloudy this morning, but will gradually become mostly cloudy by this afternoon. A slight chance of mountain snow showers will arrive later tonight. 1 to 2 inches is possible in the mountains by tomorrow morning.

Snowpack and Avalanche Discussion:

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

West to southwest winds blowing up to 80 mph stripped exposed windward slopes Thursday night into Friday. The Big Sky ski patrol reported that strong winds eroded 1 to 2 feet of snow off upper elevation slopes during the past couple of days - uncovering old crown lines that have not been seen since January. As snow disappears off some slopes, it is being deposited on others. Luckily, newly formed wind drifts have bonded well to the old snow surface helping reduce the chances of triggering a slide. Calmer winds and warmer temperatures over the past 24 hours have also helped stabilize wind loaded slopes.

However, triggering a pocket of wind deposited snow is not impossible. Yesterday, the Moonlight Basin Ski Patrol triggered a medium sized wind slab with explosives. In addition, on Thursday - the Big Sky Ski Patrol observed two small avalanches on wind loaded slopes, one which was natural and the other skier triggered. Avalanches will likely stay confined to specific wind loaded areas and initiating long propagating cracks will be unlikely. The best approach today throughout our area is identifying and avoiding steep wind loaded slopes. Also, strong winds have added yet another layer to already large overhanging cornices. Avoiding slopes directly under cornices and giving them a wide berth along ridgelines will be a good way to avoid being run over by a car or house sized chunk of snow.

A secondary concern will be the possibility of wet loose avalanches on steep, south facing slopes. If the sun shines for an extended period of time, obvious clues such as roller balls and point releases will be bull's eye data the surface snow is losing cohesion and strength. Keeping your thinking cap on and paying attention to changing conditions will be the best way to avoid being surprised.

Today, human triggered avalanches are possible on wind loaded slopes, which have a MODERATE Avalanche Danger. Slopes that have not received a wind load have a LOW Avalanche Danger.

Heads up: Cornices have grown very large in recent weeks. These monster blocks of snow now severely overhang ridges. It's hard to know when or where they will break, but these tumbling blocks of dense snow are a hazard by themselves. Approach them with caution whether walking on a ridge or skiing or riding beneath them. Additionally, falling cornices make great triggers for avalanches.

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.