Turnagain Pass

There are a variety of potentially dangerous storm related issues today. Caution is advised travelling in avalanche terrain, these conditions warrant careful route finding and conservative decision-making. We received a 6-8″ of snow that started falling in late the afternoon yesterday. We have now received over 3″ of water equivalent in the past week, equating to over 3′ of new snow in the Alpine. With the snow available to transport, winds over the past two days have created slab conditions on leeward slopes. An observer reported cracking in the upper 18″ on Seattle Ridge yesterday and triggering a small pocket of wind slab. This set-up may be more developed today and easier to trigger. 

In addition, temperatures are rising and may result in an “upside-down” structure and instabilities within the new snow. This may be more pronounced in the lower elevation bands. This means there is the potential for both wind slabs from the wind loading and soft storm slabs from the warming trend of the storm.

The snow line may rise over 1000′ today resulting in rain on snow in the lower elevation terrain. This could add additional load and saturate the snow on the ground. Wet-loose avalanches may be possible.

Watch for Red Flags (signs of instability): cracking, whumpfing and recent avalanching are all signs that the snowpack is stressed. New snow and wind may be actively creating dangerous avalanche conditions today.

We have been continuing to monitor the layer of Near Surface Facets and Buried Surface Hoar since they were buried at the beginning of this stormy period. So far they have been unreactive. However, as the slab and the load on top of this layer continues to grow they are worth remembering. This is an added reason for caution today in avalanche terrain.