Regions
Northwest Inland.
Watch for areas where reactive wind slabs may still be lingering. And keep in mind that it may still be possible to trigger a deeper weak layer, especially in thin or shallow areas.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
SUNDAY: Mostly sunny. Ridge wind, moderate, northeast. Temperature -15. Freezing level valley bottom.MONDAY: Mostly sunny. Ridge wind light to moderate, northwest. Temperature -10. Freezing level valley bottom.TUESDAY: Mostly sunny. Ridge wind light, northwest. Temperature -8. Freezing level valley bottom.
Avalanche Summary
There have been no new reports of avalanches since Wednesday when widespread natural avalanche activity up to size 2.5 was reported on wind-loaded leeward, slopes as well as loose snow releases on steep solar aspects in the afternoon.Avalanche activity will likely taper off with a period of cold, clear weather expected to persist well into the week. Watch for areas where reactive windslabs may still linger, and be extra cautious near thin spots and shallow snow pack areas where triggering a deeper weak layer is more likely.
Snowpack Summary
Winds (mostly northwesterly) have scoured wind-exposed slopes and created stiff wind slabs on leeward slopes at tree line and above. In areas sheltered from the wind, you can still find 30-50 cm of settled storm snow. A crust and/or weak feathery surface hoar layer buried in mid-January now lies about 100 cm below the surface. The crust exists well into the alpine and the surface hoar can be found in sheltered areas in the lower alpine and tree line elevations. Snowpack tests produced hard, sudden results on weak, sugary snow crystals associated with this crust in the Smithers area, indicating that this is still a layer of concern to watch for.Another two crust / surface hoar layers that were buried in December are now 100-150 cm below the surface and may still be sensitive to triggering from shallow snowpack areas.
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.