East Slopes North

Conditions will start with Low Danger as we wait for an incoming storm to arrive.  Light snow and increasing winds may develop shallow new wind slabs by late afternoon or more likely,  Friday night.  If the storm is more potent than expected, be prepared to evaluate freshly wind loaded terrain at higher elevations.  The new snow will layer over variable surfaces;  surface crusts, wind-stiffened snow and weak faceted surface snow.  

On Friday, we'll start to exit what's been a relatively quiet pattern beginning with a weak frontal system that should bring some light snow (1-2 inches near the crest, less further east of Washington Pass) along with moderate ridgeline winds by late Friday afternoon or evening.   If you're out later in the day or the storm comes in faster and/or heavier than forecast, you'll need to think about new and shallow wind slabs forming near and above treeline.  Look for blowing snow at higher elevations and if you find fresh pillow-like drifts, use caution on steep lee slopes below ridgelines where you could trigger a shallow wind slab avalanche.  While the new snow will fall on a variety of surfaces, the most touchy areas may be where the new snow builds over weak surface facets. Visual clues like cornice lines may be less helpful than usual - we're switching from a period of notable northerly winds to our more traditional S-SW storm track.  

Recent warm temperatures and sunshine have formed crusts formed on steep, sun-exposed slopes. On shaded slopes, the snow on the surface and directly above the MLK crust is beginning to facet and weaken. Some observers have reported propagating test results on this layer. While it's not currently contributing to the avalanche danger, this layer could be a concern during future storms. We've also been tracking a layer of buried surface hoar from January 5th. Near Washington Pass, it's around 2.5ft below the snow surface but shallowly buried in the easternmost portion of the zone. Snowpack tests indicate the potential for propagation above about 5,500ft or in eastern portions of the zone, where the overlying MLK crust is thin or not present. 

The snowpack near the eastern edge of the zone is more shallow, and you may find weak layers of snow more susceptible to triggering an avalanche. In the lower-elevation foothills, warm and wet conditions transformed previously weak, low-elevation snow into melt forms.  While we have little recent info here, we suspect weak layers are forming adjacent to crusts in the upper half of the snowpack.