Regions
Northwest Inland.
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain on Saturday
Weather Forecast
Overnight and Saturday: Dry and cool overnight with no precipitation. Light precipitation starting in the morning, expect 5-10 cms during the day. Winds becoming strong Southerly on Saturday. Freezing level rising up to about 1000 metres.Sunday: Light precipitation is expected to continue during the day. Winds becoming moderate Westerly. Alpine temperatures around -5.0 and freezing levels at about 700 metres.Monday: Continued light precipitation. Temperatures cooling off to about -10.0 in the alpine overnight.
Avalanche Summary
No new reports of avalanche activity. Wind slabs in the Howson Range ( Southwest of the region where it tends to get more snow) were quick to settle out after the last storm, becoming very stubborn by the day after the storm.
Snowpack Summary
The snowpack is generally shallow (about 1m deep) and strong winds have scoured some alpine slopes to ground. Wind slabs exist in many wind-exposed areas. Their distribution is quite variable and some areas have no wind-effect at all. It is still possible to find cold, low density snow at the surface in wind sheltered areas. Below treeline, very loose cold snow is sluffing easily from steep terrain and early season hazards like exposed stumps and rocks are still present in places. Professionals are still mindful of a facet/crust layer near the base of the snowpack. Although triggering it has become unlikely, it may be possible from a thin-spot trigger point or with a very heavy load (e.g. cornice fall). A size 2 natural slab avalanche triggered by a cornice fall that occurred on December 28th in the Hankin area illustrates that caution is still warranted for this layer.
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.