Avalanche forecast

Bitterroot

West Central Montana Avalanche Center
View on map

Avalanche danger

Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Open full map
Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

In the Central and Northern Bitterroot, skiers, and riders could trigger small windslab if they venture into wind loaded terrain over 35º. The southern Bitterroot is generally stable. Stay alert for red flags and continue to practice safe travel. 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    At upper elevations, wind slab could be triggered by skiers and riders on southeast aspects. 

    The central to northern Bitterroot are the most likely places to find consequential wind slab today, below ridges and along the edges of gullies. 

    Today's windslab will be small but large enough to knock skiers off their feet and could carry you into or over hazards. Terrain traps such as gullies increase the risk of burial. 

    Windlips and cornices indicate wind transport and wind direction. Smooth pillows of snow that may be stiff and hollow sounding indicate the presence of windslab, and shooting cracks are a sign of instability. 

    The best way to avoid triggering a windslab avalanche is to avoid pockets of wind loading over 35º.

Avalanche Discussion

Compared to last week, this week's weather is rather benign. Minimal snow fell in the last 48hrs, with most SNOTELS recording an inch or two of fresh. The exception is the central to northern Bitterroot, where about 8” of fresh was noted at upper elevations yesterday. Lolo and Savage Pass SNOTELS indicate around 6” of new snow. Winds have been light out of the southwest for the past 24hr. Another 1-2” will add a bit of snow for transport by today's moderate southwest winds. Mild weather for the next few days will contribute to stable conditions until the next round of snow arrives. 

Last week's winds did a number on snow conditions throughout the forecast area. Conditions are highly variable; anywhere exposed was affected. The fresh snow improved conditions in the Bitterroot but not the Rattlesnake or Seeley. Stiff windboard and exposed crusts are unforgiving and could result in injury or long slides. The best riding is found on protected slopes and in the trees. 

During the presidents day storm, periods of freezing drizzle created crust layers that are present in the snowpack. The depth of these layers varies dramatically because of the strong east winds that followed last week's snowfall. In places, such as east aspects, the crust is on the surface; in others, it is buried up to 18” deep. A layer of facets surrounds the crust in some spots. Elsewhere, it is well-bonded. There have been no recent slides on this layer, and test results have been inconsistent. However, enough have propagated to warrant caution. If you find the crust and soft snow under harder, consider stepping back to mellower terrain. 

Many thanks to the folks who’ve submitted observations; keep sharing what you find out there. 

Ski and ride safe.

 

Regions covered