A series of significant outflow (north) wind events alongside very little precipitation over the last 2 weeks has left our forecast area with a heavily wind damaged upper snowpack.  Very hard (pencil-knife) wind slabs exist on the lee side of high elevation ridges and cross loaded gullies(SE-NW). Windward aspects have been stripped down to older layers of the snowpack , with sastrugi present and in some places the ground.  Triggering an old wind slab avalanche near the surface is currently unlikely.  On 3/14 these wind slabs were found to be unreactive to triggers while traveling on slope and in stability tests.  

On 3/14 a very small amount of faceting was occurring in the continental zone atop old wind damaged surfaces.  This may create a weak layer as we begin to receive new snowfall and storm slabs begin to form.  Storm slabs have yet to form in our forecast area, and the hazard remains Low.  

Other persistent interfaces exist in the mid snowpack.  At this time, it is unlikely to affect these layers due very strong snow at the surface that is limiting the affect a person or machine would have on layers lower down in the snowpack.  Remember that unlikely does not mean impossible, maintaining safe travel protocols is recommended. 

Recent outflow winds have stripped many areas, which has led to an overall decrease in the mass of our snowpack.  Some areas did see depositions add to the depth of the pack, but the strength of winds we received has done more scouring, stripping and sublimating than redistributing and depositing.  

 The overall snowpack has become thinner over the last 2 weeks in most locations.  Depth hoar is now closer to the surface and may increase the possibility to see full depth avalanches once significant loading events occur in the future, or the suns energy is able to penetrate deeper into the snowpack on south aspects.  Another affect of depth hoar being closer to the surface is that these grains that were rounded in many locations are moving toward faceting again as temperature gradients increase.   This has been confirmed by snow pits in multiple locations in the intermountain and continental zone over the last week.  These have shown the overall snowpack to be faceting at all levels, with the most significant affects occurring in the bottom 1/3.  It is unclear at this point if this refaceting affect is significant in the Maritime climate zone.  Currently, affecting this layer remains unlikely.  Although, may become an issue later in the season especially once the weather pattern changes and heavy snowfall returns.

This weak snow mentioned above was created by early season cold temps, dry conditions and strong north winds.  Poor structure near the base of the snowpack has been observed since late November.  Mild temperatures and consistent snowfall during mid winter allowed this weak snow to slowly round and gain strength.  This weak snow has been dormant through the majority of the season with human triggered avalanches being unlikely at this layer.  As the sun came out on 2/20 for the first time in weeks several very large natural avalanches  occurred with cornice and ice falls being the triggers.  Cornice fall triggered avalanches have recently stopped being reported and these previously mentioned events were likely the mountains response to a return to sun after a prolonged period of incremental snowfall.  Human triggers remain unlikely at this layer, although these events show that large triggers can affect this weak snow.  Cornice fall will be the most likely trigger to affect this weak snow, although it is possible that a large group could have the same affect.  Avoid overhead exposure to cornices and realize that thin areas of the snowpack are the most likely to act as trigger points.