A weak and variable snowpack (from recent strong winds and cold temps) warrants a cautious approach.
Weather Forecast
Arctic air creeps into the region on Thursday and confronts the warmer low resulting in snow fall through Friday.Thursday: Cloudy with flurries (up to 5 cm). Alpine Low - 13C High -4C. Ridge wind light SE. Freezing level: 1600 meters.Friday: Flurries (up to 6 cm). Alpine Low -13 C, High -6 C. Ridge wind light SE. Freezing level: 1400 metres.
Snowpack Summary
Wind slabs and extensive wind effect found in all open areas. The upper snowpack is a 50 to 80 cm thick slab that sits on three weak layers in the mid-pack. The entire snowpack is faceting after two weeks of cold, dry weather. Whumpfing and collapses are more prevalent in the northern half of the forecast area.
Avalanche Summary
Isolated large Na avalanches were observed on a road patrol Wednesday, one windslab from a cross loaded pocket on a W aspect, and one persistent slab on an E aspect. Otherwise there has been minimal activity since the extensive avalanche cycle on February 8-9. Slopes that did not avalanche during this cycle should still be carefully assessed.
Confidence
Timing of incoming weather systems is uncertain
Problems
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.
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.