Variable surface conditions exist throughout the bulletin region. Travel cautiously in flat light.
Weather Forecast
The arctic ridge continues to keep moisture from advancing northward. Mainly cloudy with isolated flurries today, with a freezing level of 1200m. Ridge winds are forecast to be light from the SW. Freezing levels are expected to lower over the weekend, with ~ 5 cm of snowfall.
Snowpack Summary
A dusting of new snow covers old hard wind slabs, and scoured surfaces in the ALP and exposed areas of TL. Cold temps have created a weak, faceted upper snowpack. Wind slabs have been most reactive on solar aspects, where crusts are buried. The Jan 17 SH is down 50-70cm at TL and below.
Avalanche Summary
On Saturday there was a natural cycle triggered by strong N-NE winds. Since the weekend we have only seen sporadic small wind slabs and loose dry up to size 2.0 in the alpine. There have been no reports of any new avalanches on the Jan17th PWL in over a week.
Confidence
Forecast snowfall amounts are uncertain
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.