Turnagain Pass Avalanche Forecast

Although there are many human triggered avalanche concerns out there, glide avalanches remain the primary concern due to their destructive nature. This season is turning out to be a season where mapping glide cracks and limiting/avoiding time under them is just part of the game. The most recent glide we know of that has released at Turnagain Pass was 3-4 days ago on the Eddies ridge. 

Photo: Glide avalanche on Eddies, released sometime late 2/10-early 2/11.

While many folks are waiting for the skies to clear and temperatures to cool off before venturing into the mountains, it has been snowing a bit and blowing quite a bit over the past several days in the Alpine – above 2,500′. Specifically, between 1 and 2 feet of new snow has fallen over the past 3 days with winds in the 20-25mph range on the ridgetops from the East. Due to lack of travel and visibility in these areas we don’t have first hand data as to how the wind driven snow is bonding, if cornices are falling and the like. However, we know from past experience that this warm snow is quite sticky and stabilizes relatively quickly. This will most likely be the case for today and into the week. Nonetheless, things to watch for at the upper elevations:

Wind Slabs:  Steep slopes that have been, or are currently being, loaded with wind deposited snow are suspect for triggered a wind slab avalanche. These could be 1-2′ or more thick. Watching for cracking in the new snow and jumping on small terrain features and test slopes can be good ways to see how well slabs are bonding. 

Cornice Falls: GIVE CORNICES a wide berth!! these are likely to be tender with the warm temperatures and could be deadly if you were to take a fall off a ridgeline with one. Also, similar to glide avalanches, limit time spend under cornices.

*Shallow snowpack zones: South of Turnagain Pass and the Summit Lake area. These areas have old weak layers in the snowpack that, if loaded with enough snow/wind, could produce a large avalanche. This is something to keep in mind if you are headed to these zones this week with the expected clear skies.

It will be another moist day out there. Temperatures dipped to 32F at 1,000′ overnight and it is lightly snowing at the Pass this morning, but temperatures are forecast to climb up again today. Rain up to 1,500′ is possible and we have .2-.4″ of it with 2-4″ of snow in the Alpine. The snow at the mid-elevations is wet and saturated. These are prime conditions for triggering a wet loose avalanche on steep slopes. To initiate a wet loose slide the slope has to be quite steep, but once it starts moving can gain a lot of momentum and run to valley bottoms. Steering clear of steep slopes with ‘boot-top’ wet snow is an avalanche forecaster’s rule of thumb.