The current conditions require restraint and conservative decision-making. Triggering large avalanches, even from relatively low-angle slopes, remains possible.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Synopsis: A ridge of high pressure should maintain dry conditions with sunny breaks for Monday. The freezing level on Monday is around 800 m. A system hitting the coast on Tuesday could spread more cloud and light precipitation to the Cariboos/N. Columbias. This will also push in warmer air causing freezing levels to jump to 1300-1500 m. Cloudy conditions persist on Wednesday with even warmer air invading causing the freezing level to climb another 100-300 m. Winds will be on the rise to moderate or strong by Tuesday and Wednesday.
Avalanche Summary
One observer from the Mica Mountain area posted some good photos of recent avalanche activity on Saturday (probably occurred on Friday). Check out the Mountain Information Network for more info. There was also a report of a size 2.5 wind slab that was remotely triggered by a snowcat on a NE aspect in the alpine. On Friday, a large natural avalanche cycle to size 3.5 was reported near Blue River and Valemount.
Snowpack Summary
Recent snowfall and strong winds created storm slabs in many places and wind slabs on features lee to the southerly winds. This new snow has also added load and stress to the already volatile persistent slab. There are a couple of highly reactive layers of surface hoar buried in the upper snowpack (down 40-80 cm), which have been responsible for recent avalanches. The mid and lower snowpack are generally strong, with any weak layers considered dormant for now. Snowpack depths are variable and shallow snowpack areas may have weak facetted crystals near the ground.
Problems
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.
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.