Today...Mostly cloudy early in the morning then clearing. Highs 28°F to 34°F.

Tonight...Mostly clear in the evening then becoming partly cloudy. Lows 10°F to 16°F.

Tuesday...Cloudy. Chance of snow in the morning...then snow likely in the afternoon. Snow accumulation of 2 to 3 inches. Highs 25°F to 31°F. Southwest winds around 15 mph late in the afternoon. Chance of snow 70 percent.

Tuesday Night...Colder. Mostly cloudy. Chance of snow in the evening...then slight chance of snow after midnight. Lows -1°F to 5°F. Chance of snow 40 percent.

Wednesday...Colder. Partly cloudy. Highs 11°F to 17°F.

Wednesday Night...Mostly clear. Lows -5°F to 5°F.

Thursday...Not as cold. Partly cloudy. Highs 21°F to 27°F.

Thursday Night...Mostly clear in the evening then becoming partly cloudy. Lows -1°F to 9°F.

Friday...Partly cloudy. Highs 23°F to 29°F.

Friday Night...Partly cloudy. Lows 4°F to 12°F.

Saturday...Mostly sunny. Highs 26°F to 32°F.

Saturday Night...Mostly clear in the evening then becoming partly cloudy. Lows 6°F to 14°F.

Sunday...Mostly sunny in the morning then becoming partly cloudy. Highs 25°F to 31°F.

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

Mountain Weather

Over the past 24 hours a cold northwest flow dropped a trace to one inch of snow in the northern Gallatin and Madison Ranges. This weak system has been pushed to the east by a building ridge of high pressure, which is producing clear skies and relatively calm conditions.

Currently, mountain temperatures are ranging from the high teens to mid twenties Fahrenheit and winds are blowing out of the West-northwest at 5-15 mph, with the exception of the Bridger Range where ridgetop winds are blowing 25-35 mph. Today, skies will remain clear and temperatures will climb into the low 30s Fahrenheit. Winds will gradually increase through the day, blowing 20-30 mph out of West. Skies will become partly to mostly cloudy by this evening as the next weather system approaches from the west.

Snowpack and Avalanche Discussion:

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

As the weather changes so does the layering and structure of the snowpack. Without any snow events over the past week, the snowpack is slowly adjusting to last week's storm, helping improve stability. However the pack still resembles a house of cards; one wrong move and it could all come crashing down. A near miss in Cabin Creek outside of West Yellowstone on Saturday was a poignant reminder of just how unstable conditions are.

Yesterday, three of us toured into Bacon Rind in the southern Madison Range and found a snowpack comprised mainly of weak surgery facets. Our stability tests indicated the weak structure was gaining strength, but we did not trust it. We all agreed that slopes steeper than 35 degrees would likely produce avalanches under the weight of a skier or rider.

A growing problem is a layer of near surface facets, which has developed over the past week. This layer has the potential of becoming a nuisance once buried by subsequent storms.

The bottom line is the snowpack structure remains weak. A cohesive slab 1 to 3 feet thick resting over a well developed layer of facets can be found throughout much of advisory area. If you want to make it simple, today it is best to stay away from slopes steeper than 35 degrees, especially those located in high consequence terrain.

Today, human triggered avalanches are likely on slopes steeper than 35 degrees where the Avalanche Danger is rated CONSIDERABLE. Less steep slopes have MODERATE Avalanche Danger.

The northern Gallatin Range:

The northern Gallatin Range is set up better than most areas. A deeper and more stable snowpack has kept both natural and human triggered avalanches to a minimum. A weak layer of facets can be found near the ground, but it would take a heavy load or finding just the right trigger point to make this layer reactive.

Steep, upper elevation slopes, specifically those on the north and east half of the compass will be the most suseptable to human triggered avalanches.

Today, in the northern Gallatin Range, 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.

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.