Avalanche forecast

Whitefish Range

Flathead Avalanche Center
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Avalanche danger

Tue
Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
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Highlights

This is not the typical late March Low Danger day. In the past two weeks, avalanches large enough to bury a person have failed on buried weak layers. These avalanches occurred on east and southeast aspects above 6500 feet. An overnight refreeze and cooler temperatures should reduce wet avalanche activity. 

The avalanche danger may rise to MODERATE in the afternoon if cloud cover is less than forecasted. Move to shaded slopes or lower-angle terrain if you feel the surface become wet and gloppy. 

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    2–3

    Weak layers buried throughout the snowpack remain untrustworthy. Avalanche activity this month has occurred on easterly facing aspects. Likely trigger points are areas where the snowpack is thin and weak. These include rocky outcroppings and wind-swept or scoured locations where the weak layer is closer to the surface. Identifying those areas is challenging at times. Hedge your bets by steering far away from rocky outcroppings and complex-looking terrain. A simple approach is to choose slopes with lower angles. Sticking to aspects that haven't produced Persistent Slab avalanches is another way to reduce your chances of getting surprised. Those are due south-southwest-west aspects.

    (3/19/2023)

    The crown of a hard slab avalanche on Red Crow Mountain, near Firebrand Pass. The crown is 2-3 feet thick and 500 feet wide. Mountain goats may have triggered this.

    Photo: Adam Clark

Avalanche Discussion

A melt-freeze cycle is in full effect. Daytime high temperatures pushed 40 degrees F at 6500 feet yesterday (Sunday). Overnight low temperatures are in the low 20s. Today, freezing levels will rise to roughly 6000 feet. A refrozen surface, relatively cooler temperatures, and partly cloudy skies should reduce the amount of wet avalanche activity.

The best tactic for capitalizing on the melt-freeze cycle is to get up to your high point early and wait just long enough for the surface to soften. This allows for quality riding and reduces the chances of getting tangled up in a wet avalanche. If you step off your machine or ski and sink up to your knee in wet snow, then you've waited too long. Find a low-angle alternative or move to aspects shaded from the sun.  

A dose of uncertainty rests around meltwater making it to buried weak layers in the upper part of the snowpack. Yesterday, I found wet facets above the January crust. This weak layer is responsible for most of the avalanche activity in the past month. A structure like the one we have with liquid water can be a recipe for slab avalanche activity. In the same drainage I was in yesterday, another observer saw a large pile of wet debris that I did not observe earlier in the day. We are unsure if it was a loose wet avalanche or a slab avalanche. Thankfully, overnight freezes are helping the snowpack to slowly adjust to this change. 

If you choose to take advantage of the dry snow on northerly aspects, continue to be diligent about how you travel since buried weak layers still exist on those aspects. Travel one at a time and give rocky, complex-looking terrain a wide berth. Cornices are likely beginning to un-root themselves with warming temperatures. These are often referred to as “backcountry bombs” since they can tumble down and trigger larger avalanches below. These can fail spontaneously but are more likely late in the day when temperatures are warm. 

FOFAC Event: March 30th, 2023– Whether you're chasing tan lines, big lines, or both, you'll learn something valuable from FAC Lead Forecaster Mark Dundas about spring avalanche problems, how they differ from winter problems, and how to manage them. We will also discuss current conditions and concerns (or lack thereof!) with our spring snowpack. Enjoy a cold brew from Bias Brewing and a scoop from Sweet Peaks Ice Cream.

The event is free and open to everyone. Begins at 6 pm.

Regions covered