The snowpack changes dramatically from crusty travel in the valley bottom to full-on winter in the Alpine. Change your mindset with the changing conditions.
25cm of warm snow blanketed the region Tues. This sits atop various surfaces (crust, previous wind slabs) and may be more reactive where wind effect is more pronounced.
Cautiously enter leeward facing lines, especially if the slab sits on a crust.
Watch for moist/wet avalanches during peak daytime warming, especially on steeper slopes exposed to maximum solar radiation.
Unsettled weather and a gradual warming trend will be with us for the weekend.
Tonight: Cloud with clear periods, Alpine low -5*C, light SW ridgetop wind
Fri: Mix of sun/cloud, Alp high -3*C, Freezing level (FZL) 1900m, light SW wind
Sat: Sunny periods, Low -3*C, High -1*C, FZL 2100m, light SE wind
Sun: Sunny periods, Low -3*C, High 1*C, FZL 2200m
There are 2 distinct snowpacks.
Below treeline the spring-time melt-freeze snowpack is solid in the am, then breaking down with daytime warming.
In the Alpine, a winter snowpack dominates, with up to 25cm of new snow atop various older surfaces (melt-freeze crust, wind slab, or dry powder on high, sheltered, N'ly slopes).
Cornices are huge.
On Thursday, a field team observed a 24-48 hr old size 2 loose snow avalanche in the Ravens, and triggered a size 1 loose snow avalanche on a steep slope at treeline. There was also a size 3 cornice failure, in the Tractor Shed East highway path.
Crossover Gullies E and W, and Tractor Shed W, all spit out a sz 2 storm slab to half-path Tues.
