Avalanche forecast

Maritime

Valdez Avalanche Center
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Avalanche danger

Alpine
3 · Considerable
Treeline
2 · Moderate
Below
No rating
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Out of date — this forecast expired 9 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

The hazard will increase to Considerable in upper elevations today. Avalanches 1-2+ feet deep will be possible where recent storm snow has become slabby and overlies a weaker snow. Fresh windslabs will begin forming later today and will be sensitive to human triggers. Numerous glide cracks have been observed in the maritime zone. Cautious route finding and snowpack evaluation are recommended if travelling near avalanche terrain.  There is no rating for lower elevations due to minimal snow coverage. 

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–2.5

    Our early-season snowpack contains layers of weak snow underneath a recently formed slab that could produce avalanches up to 1-3 feet deep. Incremental snowfall since Thanksgiving has created 1-2+-foot-thick slabs that overlie faceted snow and surface hoar in some areas. Reactivity has recently been observed in pit tests and on test slopes within and below the top 2 feet of snow.  An additional layer of concern at the very bottom of the snowpack has also shown reactivity/propagation in pit tests. Smaller avalanches could potentially step down to ground level, producing larger, more destructive avalanches. Throughout the day and into the weekend, we can expect stress on our snowpack to increase with new snow loads and deposition of windslabs. 

     

  • Wind Slabs

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

    The National Weather Service has issued a blizzard warning for Thompson Pass from this morning to Sunday morning. Gusty NE winds and snowfall accumulations from 8-16 inches are forecasted for today and will cause the formation of fresh windslabs throughout Thompson Pass, as well as areas to the North and High elevations in Port Valdez. If you see blowing snow, it can be expected that sensitive windslabs are being formed in your area. Expect thinner/softer windslabs to form today and become thicker/harder over the weekend.  Additional snowfall, combined with wind loading, will add stress to our weak snowpack.  Keep in mind that a small windslab avalanche could create the stress necessary to trigger a deeper persistent layer, resulting in a larger avalanche.

  • Glide Cracks

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2.5

    A notable cycle of glide crack releases occurred above town after last week's wet/heavy precipitation. Over a dozen glide cracks had released in a short period of time. This problem appears to be limited to terrain above Port Valdez. Watch for cracks in the snowpack with exposed ground visible and avoid travelling underneath these features as they could release unexpectedly. 

    (12/1/2025)

    Numerous full depth Glide crack  releases on Town Mountain

    Photo: Gareth Brown

Avalanche Discussion

The weather for our early season has been mild with little in the way of impactful weather. This is begining to change into this weekend. Moving into this afternoon and evening, increasing NE winds and significant snowfall will be impacting Thompson Pass as well as the Copper River basin. Temperatures are forecasted to plummet with wind chills well below zero. New snow accumulation and wind-drifted snow will stress persistent weak layers while creating fresh, sensitive windslabs. Expect avalanche hazards to be increasing today. If you get out, dress warm and 

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