Regions
Northwest Inland.
Lack of recent avalanche activity indicates we haven't seen the loads necessary to trigger buried weak layers. Conservative route selection is still essential to staying safe while the snowpack bonds.
Confidence
Fair - Due to the number and quality of field observations
Weather Forecast
A fast-moving cold front arrives on the North Coast Thursday afternoon bringing more precipitation. Rain at lower elevations and snow above 1500 metres. Freezing level should drop to 700 metres late Thursday night, or early Friday morning. The Inland region should see 2 to 5 cm of snow on Thursday, and 5 to 10 cm on Sunday.
Avalanche Summary
No reports of avalanche activity in the region yesterday, but further west there have been reports of large natural avalanches on N and NW facing slopes around 1800m.
Snowpack Summary
Strong South winds are building wind-slabs, generally depositing snow on N and NE aspects. A rain crust is still out there up to 1600m and melt freeze crust to 1850m. Keep in mind a surface hoar layer reported to be 15 to 20cm below the surface in areas protected from the wind. We're watching the December crust, but we haven't seen any activity on it recently, most likely because it hasn't received a significant load on it. Near the base of the snowpack is a November crust-facet combination that could remain problematic for some time.
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.