Turnagain Pass Avalanche Forecast

New snow and wind have combined to create very unstable slabs in the 8-12” range.  Ridgetop winds have picked up into the 40 mph range out of the East/Southeast overnight and will remain strong through the day.  An additional 10-12” of snow and, more importantly, 1” of H20 forecasted for the higher elevations will increase the size of these slabs into the 2 foot range.  These slabs will release naturally in some locations and will be very sensitive to human triggers.  Rapid loading that occurred overnight and will continue throughout the day is enough of a trigger to initiate avalanches.

This is not a complicated situation.  Avoidance of avalanche terrain is the only way to “manage” this problem today.

A layer of weak snow that sits anywhere from 8” to 3 feet below the surface is the most concerning layer today.  Avalanches occurring in the upper layers have the potential to step down to this layer.  In cases where this happens, the volume will be large and potential for burial, if caught, is high.  Avalanches occurring at this layer have a high propagation potential, which means that fractures can and will travel across slopes and over long distances.  

Because of this travel in avalanche terrain is not recommended today (have I mentioned that already?).  While this problem exists mainly in the Alpine elevations, it will be important to avoid the runout of terrain from above when traveling in the Treeline elevations.

Rain falling on snow as high as 2,000’ will weaken the surface snow.  This will result mainly in wet loose avalanches.  Volume will be generally low, as the snow in the mid and lower elevations has already been hit with periods of rain over the past few days and has had time to adjust.  With that being said, it will be important to avoid steep terrain where the surface snow is wet.  If you find yourself sinking through the snow deeper than your boot it is time to move to lower angled terrain.  Consequences of wet loose surface snow moving will become high if pushed into or over terrain traps such as cliffs, gullies, glide cracks, or trees.