Avalanche forecast

Continental

Valdez Avalanche Center
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Avalanche danger

Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Highlights

The avalanche is moderate at upper elevations where wind loaded pockets may be possible for a person or machine to trigger up to 1 foot in depth.  The avalanche hazard is low below 4000'.  Natural avalanches are unlikely.

Public avalanche forecasts are issued Wednesday- Sunday at 8 am

Avalanche problems

  • Wind Slabs

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

    Isolated areas of windslab up to a foot thick may be encountered mostly at upper elevations today.  Observations throughout our forecast area from the last week have shown few signs of instability in most areas. The exception is small areas of instability where the wind has stiffened and deepened old storm snow.  These include slopes below high-elevation ridges in wind-channeled terrain or cross-loaded gullies. Watch for signs of wind-loaded snow such as fresh wind lips, and areas that have a pillowed look or rippled texture especially if you travel in complex or unfamiliar terrain.  Signs of instability such as shooting cracks are a bullseye indicator that wind slabs have enough energy to produce an avalanche.

    For better stability and riding quality, seek out areas that are unaffected by wind, luckily these areas are pretty easy to find right now.

     

    Signs of instability within a small pocket of wind loaded snow. Loveland Basin 2/19

    Photo: Gareth Brown

  • Loose Wet

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

    Over the last week low elevations have gone through a few small to moderate wet loose cycles with diurnal temperature spikes as well as small storms bringing in rising freezing lines.  These cycles have formed a crust at the surface as temperatures dip below freezing at night, which will need to be broken down by sun or above freezing temps for additional wet loose activity to occur.  Cloud cover is expected to limit the suns 'ability to affect the surface snow today.  Above freezing temperatures below 1000' will be the main driver of wet loose activity today, with the effect expected to be minimal.  Only minor wet loose activity is expected today, however, if the sun makes an appearance the chances for wet slides will increase and so will the potential size.

     When assessing wet loose hazards, it is essential to take the hazard in relation to the terrain you are exposing yourself to.  Are there terrain traps? Are there consequences if I were to be swept off my feet by even a small avalanche? 

    The size and shape of the terrain above you along with the amount of loose snow available to slide, directly correlates to the size of the wet loose activity that can occur. Terrain traps and exposure below you compound consequences.

Avalanche Discussion

Observed Avalanche Activity last 72 hours: 

Numerous small wet loose slides at low/mid elevation on the South side of Thompson Pass

For information about the previous Deep slab avalanche cycle, click the avalanches tab below the bottom line statement once you have entered the full forecast for a partial documentation of activity.

Three Pigs natural avalanche information click link here.

For a more detailed Keystone Canyon observation with full pit profile click link here.

Forecast Discussion:

Our area received a few small pulses of snow between 2/14-16.  Totals added up to 8-16" and has now settled down to 6-10" dependant on location and elevation.  This new snow accumulated on buried surface hoar up to 3k, with very developed grains between 1500'- 2500' depending upon location.  Despite the weak snow at the interface at specific elevations, shallow slabs (~6") have not yet created an issue except potentially for consequential low-elevation terrain.  Above 3k the new snow is well bonded to old wind-affected surfaces with a notable low amount of spatial variability. 

Benign weather with light winds and trace amounts of snowfall have typified the weather over the last few days and are expected to continue in the short term.  This has allowed a period of good stability with avalanche problems being minor wet loose activity at low elevations and small pockets of wind slab in isolated locations at upper elevations.  We are not currently tracking any persistent weak layers beneath the new/ old interface of 2/14 (hard wind affected snow).

Special note for Ice Fest:  At low elevations in Keystone Canyon there ~6 inches of dry snow above a rain crust from late January. Below this crust is a layer of facted snow.  These facets showed signs of propagation in ECT tests when isolated.  This has not been listed as a specific avalanche problem as it is unlikely for a person to cause the rain crust to fail on a slope of any reasonable size due to its connective strength.   There is a concern though, that this layer could produce human-triggered avalanches up to 1 foot in depth on steep unsupported slopes where the continuity of the rain crust could be compromised and act as a slab.

The deep slab avalanches that occurred in late January are now believed to be a dormant problem that will require a significant change in weather to reactivate.

 

Additional Information:

Active rockfall has been recently reported in Keystone Canyon.

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- 2/23 24 hour Snow Water Equivalent Inches Height of Snow February Snowfall Inches Season Total Snowfall Valdez   0    0    50     10      Thompson Pass    0    0   N/O    9    ~500 Nicks    0    0    136    6 N/O 46 Mile    0     0   22    4 N/O

Regions covered