Stay tuned to changing snow beneath you feet. Dangerous slabs have developed above treeline and should be avoided.
Weather Forecast
Cloudy with sunny periods and trace amounts of precipitation as we get a day of high pressure between storms. Alpine temperatures of -10.0, ridge winds SW 45km/hr, freezing level at 700m. The next winter storm moves in from the west tomorrow, with 6cm of snow forecast for Sunday, 18cm for Monday, 13cm for Tuesday and 10cm for Wednesday.
Snowpack Summary
Extreme S winds are redistributing storm snow in the alpine and encouraging slab development. The December 9th persistent weak layer consisting of surface hoar, sun crust and facets is buried 100cm. The November 21st persistent weak layer is down 120-160cm. Height of snow at treeline is approx 2m, and 1m at Rogers Pass.
Avalanche Summary
Explosive avalanche control produced 4 size 2.5-3.0 storm slab avalanches in the west end of Glacier National Park and 4 size 2-2.5 in the East end. In Connaught Creek, "Frequent Flyer" slide path ran naturally the night of December 13, terminating 100m past the creek. Yesterday a group observed a cornice collapse on the N side of Mt Cheops.
Confidence
Intensity of incoming weather systems is uncertain
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.