Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 4 years ago.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

Highlights

Loud, audible collapses were felt in the snowpack on Tuesday. Carefully evaluate your terrain by sticking to slopes less than 35 degrees and steer around steep breakovers. Look for areas of wind-drifted snow in unusual locations as you climb in elevation.

Avalanche problems

  • Persistent Slabs

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

    An observation from Tuesday described a collapse they felt as “rolling thunder.” This collapse carried hundreds of feet away. Take that as fuel for decision-making today. Seek out excellent and stress-free riding on slopes sheltered from the wind and less than 35 degrees. Keep tabs on the terrain you are connected to and what is above you because it is possible to remotely trigger an avalanche. 

    (12/13/2022)

    This snowpit highlights the weak snowpack structure that dominates our forecast region.

  • Wind Slabs

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

    24 hours passed since wind speeds were strong enough to transport snow. Recent north and east winds drifted snow into firm slabs on south and east aspects. These slabs will grow in size as you gain elevation. On Tuesday, observers triggered a small wind slab along with several other shooting cracks in wind-drifted snow. Slabs will slowly gain strength and become more stubborn to trigger. Steer around wind-textured surfaces on your hunt for soft snow and better riding conditions.

    (12/13/2022)

    Small, intentionally triggered wind slab. 

Avalanche Discussion

If you view the map on the observations page, it is pockmarked with orange and red icons signalling avalanches and collapses. Observations of recent avalanches are becoming more sparse, while the whumpfing collapses just don’t quit! For now, these clear warning signs make it an easy decision to stay out of avalanche terrain. Just imagine if all those collapses were triggered on slopes steeper than say, 38 degrees. They might be human-triggered avalanches instead. 

A question keeps coming up in my head, "When will I feel confident stepping out into steeper terrain?" Two scenarios come to mind:

  1. Crush and flush. I keep hoping to see an atmospheric river or moist southwesterly flow enter the area and dump a ton of moisture on us. A storm like this could cause a widespread avalanche cycle that flushes the weak snow out. We would see dangerous avalanche conditions for a period of time, but hopefully, we could then drop this persistent slab problem.
  2. Numerous days of observations with no red flags. This is a slower approach and appears to be the path we're heading towards. Here, the snowpack will become more stable over time as it's weight slowly compresses weak snow near the ground and causes grains to sinter together. Unfortunately cold, arctic air is going to make this process even slower. A large temperature gradient in the snowpack will slow the process of rounding faceted snow near the ground. 

Patience is key. The snowpack right now is similar to taking a HOT pizza out of the oven. I am the kind of person that always dives in too soon and burns my mouth. The rest of the pizza is never as good because the roof of my mouth is scorched. Thankfully, I developed a slower approach to risk in the mountains. This snowpack, like the hot pizza, needs more time before we take a bite. I’ll be waiting for consecutive days of no warning signs before I dive in to steeper terrain. Until then, low-angle riding it is.

Education - Our next Avalanche Awareness presentation is TONIGHT at Penco Power Products, Kalispell. You can get more details about these free events on our events calendar.

Observations - Thanks to everyone who's been utilizing our new observation submission page. Try it out and help your community by sharing what you see in the backcountry. The form requires you to fill out the location fields and put a dot on a map. Be as specific or vague as you want. Our new Observation View page highlights signs of instability and allows you to filter by date or zone to pull out reports relevant to your objectives.

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