Avalanche forecast

Bitterroot

West Central Montana Avalanche Center
View on map

Avalanche danger

Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Open full map
Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

As the temperature rises throughout the day, so will danger from wet loose slides. As the snow warms, move to less sun-affected areas like north-facing slopes or higher elevation. Wet sloppy snow and sinking past mid-boot means it’s time to leave avalanche terrain. Avoid traveling directly on or under cornices. 

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    During the day's heat, the snowpack will lose cohesion, increasing the likelihood of wet loose avalanches. Mostly cloudy skies should limit solar radiation, but if the sun does make an appearance, it will accelerate the warming of the snow. Terrain features like cliff bands and large rocks will increase solar warming and are likely trigger points. Wet slides should not be underestimated today. They can quickly grow in size as they travel downhill, entraining more snow.

    With temperatures forecast up to 59º degrees at 8000 feet today and a shallow freeze last night, it may be hard to get into the mountains before warming has progressed too far. Areas with a supportable crust are safe while they remain frozen, but some areas may not have frozen last night. Wet sloppy snow, sinking past mid-boot, and triggering wet sluffs on small, safe test slopes are signs that it is time to move to shadier aspects or exit avalanche terrain. 

    Plan your exit from the mountains so you are not crossing or beneath avalanche terrain late in the day.

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Cornice fall is unpredictable and is destructive. Today's continued warming will increase the likelihood of natural and human-triggered cornice fall. Cornices often break farther back than expected and can fall without warning. The best management strategy is a large margin of safety. Stay well away from the edge of cornices, and avoid prolonged exposure when traveling underneath. Cornice fall may trigger larger avalanches.

Avalanche Discussion

We are into our fifth day of elevated temperatures. At most elevations, the snowpack has transitioned into a spring snowpack and is saturated throughout. The exception is north aspects above 7500’. The March rain crust is decomposing due to moisture, and the concern for large wet slabs has diminished. However, elevated temperatures through Monday, non-freezing nights, and the chance of rain, could lead to loss of cohesion in the snowpack and increase the likelihood of very large loose wet avalanches.  

Yesterday's temperatures reached the low 50s in the Jocko at 6330ft, Stuart Mountain at 7400ft in the Rattlesnake, and Saddle Mountain at 7940ft in the Southern Bitterroot. The trend will continue today with highs forecast to 50º in the Seeley zone, 48º in the Rattlesnake, and 59º in the Southern Bitterroots.

Sunday, even warmer temperatures are forecast. Upper elevation snow above 9000ft on north aspects will become wet and destabilized for the first time this season, making it likely for human trigger and natural wet slides and cornice fall occur. 

As always, public observations are much appreciated and an essential source of information. Places submit them here. 

Ski and ride safe

Regions covered