Expect the avalanche hazard to increase on solar aspects with prolonged sun exposure.'The first kiss of the sun' after a storm often triggers a natural avalanche cycle. Human triggering of avalanches remains likely.
Weather Forecast
The first day in awhile that you won't be able to track the hourly snowfall on the brim of your sweet trucker hat. Expect cloud with sunny periods, temps from -4 to -10 and light winds from the west. No forecasted snow today. Another pacific storm is brewing off the coast and will push inland on Tuesday evening into Thursday, 40-50cm expected.
Snowpack Summary
Another 22cm brings the weekly snowfall total to 160cm adding to the already healthy sized storm slab. Previous moderate to strong south winds have created pockets of windslab in the alpine. Over a meter and a half of settling snow sits on the Jan 16th surface hoar, which is the uppermost PWL and is still distinct and easy to pick out on pit walls.
Avalanche Summary
Several natural avalanches reported yesterday from backcountry users up to size 2.5 with crowns up to 1.5m deep. Suspect these deep avalanches failed on the Jan 16th surface hoar layer. Artillery avalanche control on Saturday produced numerous avalanches, size 2.0-3.5, with several avalanches dusting the highway.
Confidence
Timing or intensity of solar radiation is uncertain on Monday
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.