February 15, 2015

The avalanche danger has again increased, this time due to another round of wind combined with a bit of new snow and warming temperatures.

Chugach State Park is rife with wind slabs (old and more recently formed), and these exist from the high alpine to lower elevations where there actually is snow.  Skiing/riding conditions are far from desirable, but these wind slabs are also a concern for hikers and climbers.  Reactive wind slabs have been found on ledges of lower angled ice and turf/rock where snow accumulates and could take a lead climber for a nasty fall.  Likewise for hikers, traversing leeward ridgelines has proved sketchy in the past week with cracking and whumphing.  Look for areas of “hollow” snow with a denser slab on top of looser, weaker snow.  Watch for cracking and whumphing; blowing snow and where it’s being deposited; and areas that look fat, pillowy, or bulbous in appearance.  These are red flags and clues to heightened potential danger.

Persistent slabs are also a concern, given the snowpack setup throughout the park.  There are multiple buried persistent weak layers, especially crust-facet combos.  Persistent slab avalanches are harder to identify-assess, and could produce larger hard slab avalanches that are difficult to escape.  It will be necessary to dig into the snow and analyze-assess the snowpack through snowpits, stability tests, and layer identification to better grasp this hazard.

Considering the recent warmup that is expected to persist through the week, wet avalanches are also becoming a concern.  These will initially be confined to loose wet avalanches but as warm temperatures persist, especially if they remain above freezing day and night, wet slabs may become more of a problem.  Water percolating through the snowpack has the potential to initiate deeper persistent slab avalanche problems.

Stay safe out there, and remember this information is time-sensitive and only one piece of the avalanche assessment puzzle.  Conduct your own assessment of conditions and use the info provided here as just one reference point.

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