Turnagain Pass

Loose Snow Avalanches

New snow in the past 24 hours fell in many places without any associated winds.  Up to a foot of new snow can be found in the upper elevations with half that amount in the lower elevations.  This snow is “right side up”, as temperatures overnight have gradually cooled.  Loose snow avalanches will be a concern on steep upper elevation slopes today.  Periods of sunshine will increase the likelihood of triggering these slides.  These avalanches have the potential to knock people off of their feet or snowmachines.  As such it will be best to avoid steep slopes above terrain traps where sloughing could pull people into gullies, over cliff bands and into trees.

Wind Slabs
In the upper elevations isolated pockets of older wind slab may be triggered by a skier or rider today.  These pockets will be harder to detect, as a blanket of lighter density new snow sits on top of these slabs.  Staying off of steep previously wind loaded terrain features will help in avoiding this problem today.
With light to moderate winds forecasted for today, expect to see shallow new wind slabs forming near ridgetops through the day. With ample light density snow available for transport, expect these slabs to form easily and be most sensitive as they are forming.

The mid elevations (between 1,500-2,800′) have a snowpack structure that has some potential to produce larger more dangerous avalanches.  A crust formed in late January has a very thin layer of weak snow above it in many areas.  Above that weak layer are slabs ranging in depth from 1-3 feet.  We have been investigating the likelihood of triggering an avalanche on this interface and have found mixed results within our forecast zone.  In some areas snowpit tests have shown this layer to be reactive and in other areas it has been a non issue.  While we’ve only had one report of a human triggered avalanche on this layer in the last week, the potential still exists.  The best way to avoid this problem is by managing your terrain and staying away from potential trigger points (e.g., steep rollovers, areas of thin snow) within this elevation band.