Turnagain Pass

Forecasted 40-55 mph east winds are guaranteed to build very tender and sensitive wind slabs with yesterday’s 4-8” of light powder combined with today’s storm snow.  As you gain in elevation, slabs will be actively forming throughout the day on a variety of bed surfaces including breakable crusts, buried surface hoar (observed on Tuesday in Girdwood and Turnagain) and in the upper elevations older wind slab.

Below tree line where winds are not as intense, avalanche size is likely to be small though human triggered avalanches will be possible.  Slabs will form mostly on a breakable crust at these lower elevations. 

Above tree line expect slabs to form in all the usual places; below ridgelines on west-facing (leeward) slopes and cross-loaded gullies.  With moderate to high winds, slopes tend to load further downhill than one would think, often luring a skier or snowmachiner mid-slope before finding the trigger point.  The likelihood of triggering a slab in terrain greater than 35 degrees today is probable; there is however some uncertainty on just how big an avalanche may be.

As a fresh shot of wind and moisture rolls in today it is worth mentioning that at higher elevations there still exists weak, faceted snow at the bottom of our pack.  Though we have not seen an avalanche fail on this layer in several weeks, deep slab instabilities are notorious for lying dormant for long periods only to suddenly awake and catch us off guard.  At this point, safe travel protocol will be your best bet to avoid this avalanche concern.

If you happen to find areas sheltered from the wind today, yesterday’s low-density powder combined with storm snow will create fast-moving loose snow sluffs in steep terrain.  If expected, these loose-snow slides should prove quite manageable.