Avalanche forecast

Continental

Valdez Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Today our avalanche hazard is moderate throughout the region. The gradual accumulation of snow over the last week has built storm slabs up to  2 feet thick in areas.  Instabilities within and below this new snow make it possible to trigger an avalanche 1-2 feet deep today. 

Avalanche problems

  • Storm Slabs

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

    The gradual accumulation of snow over the last week has led to the formation of a significant storm slab in some areas. Observations have shown highest amounts of snow at mid to upper elevations in coastal drainages. With additional snow that fell last night some areas are expected to have a storm slab up to 2 feet thick today. 

    Areas with buried surface hoar under storm storm snow will be the most likely spots to trigger an avalanche today. From Thompson Pass North fresh snow has been gradually loading a layer of surface hoar that became buried on 3/9.  An additional 6 inches of snow from last night has further increased the loading of this weak layer. Widespread cracking, whoomphing, or collapsing may indicate you are on a slope with buried surface hoar beneath the storm slab. In this situation, it would be possible to trigger an avalanche 1-2 feet deep large enough to bury a person.  

    Areas that lack buried surface hoar will have a lower likelihood of an avalanche being triggered by a human. Moderate winds that occurred before the burial of this surface hoar have likely destroyed it in some of the windier areas near the top of the pass. Over the last couple of days storm slabs in the maritime region lacking buried surface hoar had fair to good stability depending on the slab character of the new snow. 

    Sensitivities also exist where storm snow has been stiffened by wind. Stiffer/slabby snow has been observed to support crack propagation with ski cuts over the last couple of days. Commonly windy areas on or near Thompson Pass may have reactive windslabs up to  1ft deep. These will likely be obscured by the new snow that fell last night.  Undisturbed storm snow lacking slab character has shown minimal reactivity within the new snow in areas without surface hoar. 

    Using small test slopes, and hand/quick pits to test the depth and sensitivity of the new snow while looking for surface hoar will be good practice today.  Slabby snow or snow overlying surface hoar should be approached with caution. 

     

Avalanche Discussion

The quality of our surface snow has gradually improved with incremental snowfall over the last week. An additional 4 inches in town and 6 inches at Thompson Pass overnight has brought totals from 10-20+ inches throughout our forecast area. Avalanche hazard today will be focused on instabilities within or just below this new snow. Below this, hard surfaces and a well-consolidated snowpack have been gaining strength making deeper avalanches unlikely.

Areas, where surface hoar from 3/6 - 3/7 is buried, will be the most likely spots to encounter poor stability today.  Surface hoar is expected to be found in specific areas from Thompson Pass to the North and will be most likely to be found on protected North faces. Activity on this weak layer is likely to increase with significant snowfall over the weekend.  

We are headed into the time of year when wet loose avalanches on southerly aspects become more common. For today the problem is off our list due to cloudy skies and cooler temperatures. Recently small wet loose avalanches have been observed on SE, S, and SW slopes in lower elevations. 

 Glide cracks exist in isolated areas and will be a hazard throughout the season until they fail.  Avoid exposure to glide cracks.

Regions covered