Avalanche Forecast

Wind slab will most likely be found on northwest to southeast aspects near and above tree line. NW winds will redistribute new snowfall to lee SE slopes near and above treeline Monday. 

Wind and storm slab avalanches should stay within recent storm layers but colder temperatures along the east slopes of the Cascades will help slow bonding of newly formed wind slabs to the weaker layers underneath. Test for inverted strong over weak storm snow and give cornices a wide margin.

Beware of loose dry avalanches in steep non-wind affected terrain that could have unintended consequences such as knocking you off your feet and into a terrain trap.

There have been snow immersion fatalities in tree wells already this season at Snoqualmie and in Canada. Recent unconsolidated storm snow is still very deep in places with possible large tree wells lurking, so stick near your partner in the trees and maintain visual contact.  

For the week ending on Dec. 24th, a snowy and cool storm cycle brought 2-4 feet of snowfall to the east slopes. Only light additional accumulations over the last few days have allowed the snowpack to gradually settle, but it remains deep out there with Washington Pass area snowdepths over 2 meters and fine riding conditions reported!  The upper snowpack should generally be right side up with increasing hardness with depth. Moderate southerly transport winds in the alpine with Sunday's system may have built new wind slab on NW through E aspects. 

A snow pit report from 5700-6500 foot range in Stemilt Basin near Mission Ridge also on Tuesday indicated a buried surface hoar at 45 cm. This layer gave some cracking and whumping.  There have not been any recent reports from the Mission Ridge area. 

Storm instabilities reported last week have likely settled out, but the North Cascades Mountain Guides reported on Christmas Day, a buried surface hoar layer in the Washington Pass area around 40 cm down that gave sudden planar (pop!) results in compression tests, but was not found to be involved in any natural or skier triggered avalanches. This layer probably needs more of a cohesive slab above it before it becomes apparent whether this is an PWL issue or not. 

The southeast zone has a relatively shallower snowpack versus areas further north but after a snowy few weeks, has more than enough snow to warrant an avalanche risk. No snowpack observations have been received from this zone.