Avalanche Forecast

Fair

The next three days look cool and dry, with sunny spells. The freezing level is around 1400 m on Sunday, falling to valley floor overnight as a strong ridge sets up. It is expected to get into a diurnal cycle after that (falling to valley floor at night and rising by day to around 1200 m). Winds are generally light from the NW.

A warming-related natural avalanche cycle occurred on Thursday and Friday. Many cornices also collapsed naturally and with explosives over the last few days, occasionally triggering slabs on the slopes below. Skiers triggered a very large (size 3.5) persistent slab on Thursday on a NE aspect in the alpine in the Monashees. It failed on the late-Jan layer. Avalanche activity is likely to taper off with cooling temperatures, but large avalanches remain possible, and sun may cause another spike in avalanche activity on steep solar aspects.

As the weather finally cools after ten days of very warm temperatures and bursts of rain, surface crusts are likely to form. Underneath newly formed crusts, you may find moist snow for a few days yet. At alpine elevations, new wind slabs or storm slabs may be found. Cornices may be large and weak. The late-Jan crust/surface hoar layer, buried up to a metre deep, remains a key concern. Recent avalanches on this layer have been very large. The mid-January surface hoar is typically down 80-120cm and is most likely to be triggered from thin or rocky snowpack areas; or perhaps with a cornice fall, or an avalanche stepping down. The mid-December weak layer is down over 120cm, but is generally considered unreactive.