We spent the weekend up in Hope Creek, the drainage east of Railroad Pass or north of Tenquil Lake. At 1450m it was -17 when we arived on Friday night, and 0 when we left on Sunday evening.
We found a prominent weak layer in the upper snowpack, that was settling out with warming temperatures. This layer was the interface between the snow that fell on Weds/Thurs (Nov 30) and the previous snow. In the Alpine this layer was very wind affected and varied from 5-50cm deep. At treeline and below this interface was 18cm deep and equally reactive, but the surface snow was very light. We saw two size 2 avalanches on steep NE terrain in the alpine that probably occurred on Thursday or Friday. In the alpine steep rolls would produce small avalanches (so we stayed away from the big stuff) and at treeline and below it would slough off.
In technical terms we were finding Easy to Moderate (SP) shears down 18cm (HST) on a cold stellar layer, which was preserved under 1F to P dense slabs in the alpine.
While we were out there we watch the Surface Hoar grow to about 1cm in size, before getting wiped out (in our valley) to about 1650m by above freezing temperatures.
We skied it like:
Saturday: Alpine-Considerable, Treeline-Moderate, Below Treeline-Moderate
Sunday: Alp-Moderate, TL-Moderate, BTL-Moderate
If I were to go back in the next few days I would be really keeping an eye out for that newly buried surface hoar layer and checking to see how the next layer down is reacting.
Conny Amelunxen
MG, ACMG
Be one of the first to try Windows Live Mail.