Hatcher Pass

Avalanche problems

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–2.5

  Moderate danger combined with a persistent slab problem can be a perplexing problem and hard to navigate. With last week's storm bringing up to 12" of new snow, long duration strong winds, and a natural avalanche cycle 4–5 days ago, we are still using a conservative mindset in our backcountry assessment.  Above 2500' it remains possible to human trigger a persistent slab large enough to bury, injure, or kill. Natural avalanches are unlikely today.  Slabs will be more stubborn to trigger today, but any avalanche triggered will be larger in size, having more propagation potential.  Remotely triggered large avalanches may still be possible.  It will be unlikely, but the possibility remains to trigger a small slab avalanche in low elevation terrain in isolated locations like cross-loaded features, steep slopes, and gully side walls. 

  After last week's Cold rain and snow with wicked winds, Hatcher's landscape looks less than enticing.  Windward aspects are stripped down to rock and alders, while leeward aspects hold all the snow.  With decent visibility today it will be possible to see loaded and crossloaded features where we can expect to find thicker and more cohesive slabs sitting over weaker sugary snow from earlier in the season.  The most likely scenario for triggering an avalanche today will be finding a shallow spot on one of these features where the continuity of the slab and weak layer exists. Staying on smaller, less consequential and less connected terrain will be a good way to beat the odds today. 

  Recent avalanches, shooting cracks, and collapsing are red flags for this problem. Stiff snow over weaker snow is also an indicator of this problem and is easy to identify with probing.

  WIND SLAB: For the past 20 hours, winds have been reported gusting ESE 30-49 mph on Hatch at 4500'.  It may be possible to find new shallow wind slabs 1-4" thick that formed in the last 24 hours.  Expect these slabs to be isolated to ridgelines on northerly aspects. Fortunately, a limited amount of snow is available for transport from southerly aspects and combined with the cheesecake consistency of the snow will limit the size of new winds slabs we expect to find today.