Use extra caution at treeline where persistent weak layers have been most reactive. Be aware that wind slabs could step down to these layers.
Variable winds have created wind slabs on all aspects. As southerly winds increase the largest and most reactive wind slabs will be found on north aspects.
A layer of facets formed during the period of arctic air is found down 30-50cm. This layer has recently produced natural avalanches at all elevations. It is likely most reactive at treeline where surface hoar could also exist as part of this layer.
Natural avalanche activity has tapered off on this layer but human triggering is still possible.
Over the past few days we received several reports of previous natural avalanches up to size 2.5. These avalanches released in the facet layer produced during the recent period of arctic air. These avalanches have occurred at all elevations and on a variety of aspects.
Check out this MIN report from our field team for some photos and a good summary of this type of activity.
If you are headed out into the backcountry please consider filling out a Mountain information Network report.
Around 30 to 40cm of recent snow has been redistributed into wind slab in exposed terrain at treeline and above. In non-wind effected terrain this recent snow sits on a layer of facets formed during the period of arctic air. Below treeline a thin crust can likely be found at or near the surface.
A surface hoar and facet layer from early December, while spotty, can still be found down around 60cm.
Snowpack depths are highly variable throughout the region.
Sunday Night
Mainly cloudy with clear periods and isolated flurries, trace accumulation. Light southerly ridgetop winds occasionally gusting 40km/h. A low of -6 at 1500m. Freezing levels valley bottom.
Monday
Cloudy with sunny periods and isolated flurries, 1-5 cm. Ridgetop winds southerly 30 to 50 km/h. A high of -4 at 1500m. Freezing levels 400m.
Tuesday
Mostly cloudy with sunny periods and isolated flurries, trace accumulation. Ridgetop winds southerly 20 km/h. A high of -5 at 1500m. Freezing levels valley bottom.
Wednesday
Mix of sun and cloud. Ridgetop winds southerly 20 km/h. A high of -6 at 1500m. Freezing levels valley bottom.
More details can be found in the Mountain Weather Forecast.
