Travel is reported to be challenging, so we may not have observations from the places where avalanches are most likely to occur. Be cautious if you're pushing into previously unridden areas.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
THURSDAY: Mostly dry with some sunny breaks. Ridgetop winds southwest 40-60 km/h. Treeline temperatures rising to around -4C after a cold morning. FRIDAY: Mostly dry and clear. Winds becoming light northwesterly. Temperatures around -4C.SATURDAY: Flurries in the afternoon. Moderate southwesterly winds. Temperatures around -12C.
Avalanche Summary
No slab avalanches reported on Wednesday. On Tuesday, ski cutting produced a size 2 wind slab in the most recent storm snow. Natural loose dry avalanches up to size 1.5 have also been reported out of steep terrain the past few days.
Snowpack Summary
Up to 20 cm of fresh low density snow is being redistributed by southwesterly winds and forming wind slabs in the lee of ridgetops. In general, there is very little structure to the snowpack, with low density new snow sitting over soft, sugary facets. Travel is very challenging as a result. A variable interface that formed during the cold snap in early December can be found buried 30-50 cm deep. This interface consists of weak faceted (sugary) snow and preserved surface hoar in sheltered areas. The interface is likely most reactive in wind-affected terrain where it is covered by hard wind slabs. The snowpack is a generally weak and faceted below this interface, including another weak layer with surface hoar or facets that was buried in early December. Hazards such as stumps, rocks, and open creeks are still a major concern.
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.