Use extra caution at treeline and below where persistent weak layers have been most reactive. Be aware that wind slabs could step down to these layers.
Natural avalanche activity has tapered off but human triggering of persistent slabs is still possible.
winds have been variable over the past few days. wind slab could be found on all aspects and elevations. Below treeline cross loading could be found due to previous outflow winds.
There are 2 persistent weak layers in the top meter of the snowpack. The first is a layer of facets formed during the period of arctic air and buried on December 22nd. Surface hoar could also be found at this interface in sheltered treeline features.
The second is a layer of facets and surface hoar from early December. This layer could be buried as deep as 1 meter.
Both these layers are most concerning in sheltered features at treeline and below where surface hoar is more likely to be present.
Over the past few days several avalanches have been triggered at treeline and below on the layer of facets formed during the recent period of arctic air. Triggers have included vehicle remotes, skier remotes, naturals and explosives. These avalanches have generally ranged in size from 1 to 2.
wind slabs could be found on all aspects in the alpine and treeline, below treeline cross loading will likely be found in all coastal inlets due to recent outflow. At treeline a new surface hoar layer from late December is just below the surface. A new crust exists on or near the surface below 1000m.
40 to 70cm overlies a layer formed during the previous period of arctic air. In the alpine this layer is generally facetsbut surface hoar could be found. At treeline it is more likely to find surface hoar at this interface in sheltered terrain.
A layer of surface hoar and facets from early December can be found down 70 to 100cm. recently this layer has not been reactive but still produces sudden results in snowpack tests.
Saturday Night
Cloudy with flurries bringing up to 5cm of new snow. Light to moderate westerly winds and a low of -4 at 1500m.
Sunday
Cloudy with trace amounts of new snow expected. Moderate to strong south winds. Possible temperature inversion with a high of -1 at 1500m and -6 at 700m.
Monday
Stormy with 5 to 15cm of new snow expected. Moderate southerly winds and a high of -2 at 1500m.
Tuesday
Cloudy with a few centimeters of new snow expected. Light easterly winds and a high of -4 at 1500m.
More details can be found in the Mountain Weather Forecast.
