Northwest Coastal

If 20cm of snow or more is on the ground by noon on Monday, consider alpine and treeline danger to be HIGH.

Fair - Intensity of incoming weather is uncertain

Monday: 10-20 cm new snow expected with strong SW ridgetop winds gusting to 60 km/h. Treeline temperatures around -6C. Tuesday: up to 10 cm new snow. SW winds gusting to 45 km/h. Treeline temperatures around -7C. Wednesday: Dry. Light winds. Temperatures around -10C.

A cycle of natural and human-triggered (including remotely-triggered and helicopter-remote) avalanches of up to size 2.5 was observed on Thursday and Friday across the region. The storm snow has been propagating easily on buried surface hoar and facets. Skiers recently triggered avalanches that resulted in wide propagation in the Shames Backcountry, highlighting the surprising reactivity of the snowpack.

30-70cm of recent storm snow is bonding poorly to old snow surfaces, especially near Terrace. The old snow surfaces comprise of surface hoar crystals and/or facets. A few days ago, this layer was being triggered naturally or remotely and propagating widely. Near Bear Pass, reports indicate the storm snow may be bonding slightly better. Recent strong southwesterly to easterly winds have set up wind slabs in many exposed lee areas. There are two surface hoar layers in the upper snowpack. The upper one formed at the end of December and is buried on average 50 cm below the surface. This one is particularly reactive at present. The lower one formed at the beginning of December and is buried around a metre below the surface. There are no recent reports of activity on this layer. Near the base of the snowpack, a crust/facet layer continues to give hard, sudden results to no results in snowpack tests. This weakness is unlikely to be triggered by a single person, but it remains possible with a very heavy load (e.g. cornice fall) or from a thin-spot trigger point.