January 11, 2014

Weekend Avalanche Outlook

Saturday & Sunday:

ds-mod

Click here to see the complete danger scale

The lowdown:

Snowpack data and skiing experience this week suggests that stability is the most suspect in the northern advisory area (Eagle River), although the Front Range still harbors a snowpack with persistent weak layers capable of failing and propagating as well.

Primary concern:

persistent slab

Click here to learn more about persistent slabs and management of this type of danger

Persistent slab problems; primarily consisting of melt-freeze/rain crusts (bed surface), faceting grains on top of the melt-freeze crusts (weak interface/layer), and wind-packed hard slabs above; are widespread throughout the Front Range and Eagle River area Chugach.

Snowpit stability tests from Wednesday and Thursday showed continued failure and propagation potential of such persistent instabilities.  Expect thinner, rockier, weaker areas of the snowpack, in upper elevation terrain with sufficient coverage, to be the most likely places to trigger a large and dangerous persistent slab.

wind-slab-12

Click here to learn more about wind slabs and management of this type of danger

Wind slabs, generally less than a foot deep, are a possibility – more so to the north in the Eagle River area.  Expect the problem, in both the Front Range and Eagle River areas, to be the most suspect in the upper elevations near peaks and along ridelines on west to north aspects.

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Be on the lookout for red flags of instabilities: wind loading, recent avalanches, whumphing (collapsing), shooting cracks, hollow sounding snow (denser snow on top of less consolidated snow), and specifically for the wind slab problem: snow that looks fat, pillowy, or loaded.

As always, if you are in avalanche terrain assess the snowpack and consequences for yourself.  Click here for a list of local educational opportunities through which you can learn how.

Here’s a couple online tutorials:

Online Avalanche Course provided by the Canadian Avalanche Centre

Avalanche Awareness provided by the Forest Service National Avalanche Center

Mountain weather:

Saturday: Cloudy, light winds, and temperatures in the upper teens.

Sunday: Cloudy with a chance of light snow, light winds, and temperatures in the upper teens.

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