Watch for rising temperatures that will cause avalanche hazard to increase this afternoon. Expect reactive slabs around treeline.
Weather Forecast
It will remain cloudy today, but a ridge of high pressure deflects any precipitation from the region. Freezing levels rise to 1400m with the possibility of an above freezing layer at higher elevations. Ridge winds west 25-40 km/h.
Snowpack Summary
In specific locations, strong S winds have redistributed storm snow and created loaded pockets and wind slabs on lee and cross-loaded features at treeline and above. The Jan 17 persistent weak layer down 30cm is surface hoar in sheltered areas and sun crust on solar aspects.
Avalanche Summary
A natural size 2.0 was observed in the highway corridor east of Rogers Pass on steep north facing terrain on Macdonald Gully #3 slide path. We received reports of fast sluffs in steep terrain below treeline where unconsolidated snow is moving over buried surface hoar crystals.
Confidence
Freezing levels are 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.