Bollettino valanghe

Continental

Valdez Avalanche Center
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Pericolo valanghe

Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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Non aggiornato — questo bollettino è scaduto last year. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

The avalanche hazard is Moderate at all elevations.  Human triggered avalanches are possible 1-2 feet in depth involving the most recent snowfall.  Wet loose natural avalanches are possible.

Avalanche Forecasts are issued Wednesday-Sunday at 8am.  

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2.5

    The period from 3/16-3/19 saw snowfall totals that ranged from near 3 feet at upper elevations near the coast to ~20 inches near Thompson Pass and less than a foot in the Continental zone.  This new snow fell on a widespread layer of buried surface hoar, which is a variety of snow that is weak and has the potential to create instability in the upper snowpack that can persist for long periods.

    Observations after 2 days of settlement have shown lots of users testing avalanche terrain in the mid elevations of Thompson Pass with no human triggered avalanches observed or reported in the last 24 hours.  Steep upper elevations remain untracked in many areas.  Tracks are not necessarily a sign of stability with this problem, although the amount of tracks on slopes that previously had widespread surface hoar is a good sign that this layer is stubborn to triggers along the Thompson Pass corridor.  Continued assessment is advised especially when branching out into new zones.

    Instability involving this layer has been reported by heli ops in the Continental zone despite lower snow totals, and in the glaciated terrain south of Thompson Pass.  The sensitivity of this layer is expected to be variable dependent upon location and creates a situation where snowpack assessment can be challenging and confusing for users.  Keep in mind that the terrain in the Thompson Pass area is vast and diverse.  Just because you experience good stability on the buttresses of Gully 1 does not mean the same stability will exist in the Hoodoo or other areas.  More observations are needed to gain a better understanding of the sensitivity of this persistent weak layer.

    Human triggered avalanches remain possible that would be large enough to injure, bury or kill a person.

     

    (3/19/2025)

     Natural avalanche in the books that likely failed on 3/16 BSH

    Photo: Eagan Gleasson

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    Skies are forecasted to be more overcast than yesterday, however it is likely that the sun will win out over the clouds at some point today.  Slopes that are being heated directly by the sun will be susceptible to wet loose activity.  Steep rocky terrain will be the first to be affected.

    Wet loose activity is a secondary concern to problem 1 listed above.  Steep terrain that produces wet loose activity will also have the potential for slab avalanches to fail naturally or be human-triggered.   Avoid steep terrain that is being heated up by the sun.  Even small slopes can be dangerous if they are above terrain traps or exposure.  

    Expect southerly aspects to be active in the coming days when the sun is out as new snow sheds from sunny slopes in the form of slab avalanches and wet loose activity.

Avalanche Discussion

Observed Avalanche Activity last 72 hours: 

Numerous D1-D2 Natural and Human triggered avalanches reported from all forecast zones over the last 3 days.

Forecast Discussion:

Assessment of the snowpack currently revolves around a layer of buried surface that is beneath the 1-3 feet of new snow that fell last week.  This should be everyone's main focus when deciding if a slope is safe to ride.  After 2 days of slope testers pushing into steeper terrain this layer has not shown a high sensitivity along the Thompson Pass road corridor, however sensitivity will likely vary from place to place.  Try not to be lulled into complacency, conditions are far more dangerous than they were just a week ago.

Slopes that are directly in the sun will gain cohesion and can increase sensitivity during the day.  Most of the natural activity that has been noted has been on south aspects, likely due to an old melt freeze crust acting as an effective bed surface.  As days continue to warm West-Northwest aspects may increase in sensitivity during peak warming as slabs gain more cohesion.

This setup is not only dangerous but can be difficult to assess.  The first person to ski a slope is not necessarily the one that will trigger an avalanche, a slope can fail after numerous tracks have been laid down.  Digging snowpits is a good tool, but can give misleading results as buried surface hoar can be easily missed depending upon where you dig.  In addition, ECTN results are not necessarily an indication that the slope is safe. Deep burial of surface hoar layers may create false stable results in pit tests. It is important to consider that we have several factors pointing to an unstable snowpack. These include: a persistent buried weak layer, a thick cohesive slab, recent avalanche activity, and increasing temperatures in many areas.   Conservative terrain choices and cautious route finding are recommended.  Only expose one person to a slope at a time, know your safe zones maintain good communication with your group, and watch out for other groups that may be recreating in the same area.

Additional Information:

Watch out for cornices. A couple of cornice falls have been observed in the Continental region.

A weather and snowpack season history is available by clicking on the Season Summary tab which is located below the bottom line statement once you have entered the full forecast.

Season Snowfall Data

Location 24 hour Snowfall Inches- 3/22 24 hour Snow Water Equivalent Inches Height of Snow March Snowfall Inches Season Total Snowfall Valdez    0    0    58     18 N/O     Thompson Pass    0    0   N/O     ~24    ~500 Nicks    0    0    146    15 N/O 46 Mile    0     0   22    5 N/O

Regioni coperte