Watch for pockets of stiff wind slab at upper elevations from recent winds. These slabs may be in atypical areas due to reverse-loading.
Avoid shallow areas where the snowpack transitions from thick to thin and triggering deep weak layers is more likely.
Look for wind-affected snow on all aspects in exposed treeline areas and in the alpine. Variable moderate winds have redistributed 15 cm of storm snow into stubborn wind slabs at higher elevations. Watch for reverse loading and cross-loading in unusual spots.
Faceted grains make up the lower snowpack and are gaining strength very slowly. Although deep persistent slab avalanches have not been reported in the region for some time there is concern that this layer remains an active avalanche problem in the northern, data-sparse parts of the region. In these areas, this layer could still be triggered with a heavy load, like a cornice fall, machine trigger, or in areas with a thinner snowpack.
On Sunday, a few natural, size 1 to 1.5, wind slab avalanches were reported at higher elevations.
On Saturday several thin wind slabs, up to size 1.5, were reported to be reactive to natural and human triggers.
Please continue to share any observations or photos on the Mountain Information Network.
15 cm of storm snow has been redistributed by variable winds in the alpine and at treeline. New snow sits over a crust on southerly slopes, previously wind affected surfaces in exposed areas and over a layer of surface hoar in sheltered areas.
A crust and facet layer from mid January, 2 to 15 cm thick at treeline sits 50 to 90 cm deep. Where it's thickest, it caps the settled and consolidated mid-snowpack.
The lower snowpack contains weak and facetted grains from November. The total snowpack depth ranges between 120 and 250 cm.
Monday Night
Mainly cloudy with isolated flurries. Moderate northwesterly winds gusting 40 km/h. Alpine high of -17°C.
Tuesday
Cloudy with sunny periods and isolated flurries, trace accumulations. Westerly ridgetop winds 40 km/h. Alpine high of -13°C.
Wednesday
Cloudy with sunny periods and isolated flurries, trace accumulations. Westerly ridgetop winds 40 km/h. Alpine high of -8°C.
Thursday
Sunny with cloudy periods. Southwesterly ridgetop winds 40-60 km/h. Alpine high of -5°C.
More details can be found in the Mountain Weather Forecast.
