Avalanche forecast

Intermountain

Valdez Avalanche Center
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Avalanche danger

Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Out of date — this forecast expired last year. You’re viewing past conditions, not the current bulletin.

Highlights

The avalanche hazard is Considerable above 3000'.  The intermountain zone has received 8-12+ inches of new snow.  Human triggered avalanches are likely up to 1 -1.5 feet in depth at upper elevation in areas where the wind has created deeper/stiffer pockets.  Natural avalanches are possible.

Avalanche Forecasts are issued Wednesday-Sunday at 8am.  

Avalanche problems

  • Storm Slabs

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

    The main avalanche concern to pay attention to today will be the new snow that has fallen over the last 48 hours.  The sensitivity of this layer will depend upon the depth of the new snow, how much has the wind redistributed the new snow, and what is at the interface of the new snow.  All of these factors will cause the sensitivity and hazard level to differ.

    Coastal areas received the highest amounts of new snow with 12-18+ inches.  Thompson Pass has been observed to have 8-12+ inches and the continental zone much less with a trace - 4+ inches estimated.  An inch or two of additional snowfall is possible today that will once again be focused along the coast.

    Initially this new snow has been observed to be uncohesive (no slab) up to mid elevations despite increasing temperatures.  Where the new snow remains uncohesive there is less risk of triggering a slab avalanche.  This situation will change over time as new snow naturally settles and creates a slab.  Areas to watch out for today will be places where storm wind has redistributed new snow into deeper and stiffer pockets.  This change in the snow density can be subtle and vary even on a single slope especially as you gain elevation.  Use caution today as this subtle change can make the difference between the snow being unreactive, or capable of producing an avalanche.

    New snow is falling on a widespread layer of surface hoar that was buried on the 16th.  This is a weak layer in our snowpack that will need to be monitored in the future.  This layer at the interface will make new snow more sensitive to human triggers in areas where storm wind has created some amount of cohesion to the new snow.  

    Pay attention to the depth of the new snow and its character (how cohesive/slabby?).  Watch for signs of instability such as recent avalanche activity, shooting cracks, and collapsing.  Small inconsequential test slopes and hand shear pits are effective tools for determining the sensitivity of the new snow.

Avalanche Discussion

Observed Avalanche Activity last 72 hours: 

None

Forecast Discussion:

Our area has just received a nice refresh of snow atop buried surface hoar, which is a weak layer. Today's sensitivity of this weak layer will depend upon the depth and the amount of wind effect on the new snow.  It may be counterintuitive, but the sensitivity of the weak layer may increase in the next few days as the new snow settles with time and a cohesive slab forms.  That's not to say that today is a safe day to go ski steep terrain, its not.  But rather the distribution of reactive snow could increase and move into moderate terrain over the coming days as the current light and fluffy storm snow settles and forms a slab above a persistent weak layer.  Don't expect the 24 hour rule to work with this cycle.

It is unknown how preserved and reactive this buried surface hoar is and will become, but it is currently guilty until proven innocent.

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- 3/16 24 hour Snow Water Equivalent Inches Height of Snow March Snowfall Inches Season Total Snowfall Valdez    6    N/O    58     18 N/O     Thompson Pass    N/O    N/O   N/O     18    ~500 Nicks    1    N/O    146    15 N/O 46 Mile    Trace     Trace   22    5 N/O

Regions covered