Avalanche Forecast

Issued: Feb 14th, 2015 7:39AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Persistent Slabs, Wind Slabs and Loose Wet.

Avalanche Canada pgoddard, Avalanche Canada

A Special Public Avalanche Warning is in effect for this region.

Summary

Confidence

Fair

Weather Forecast

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.

Avalanche Summary

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.

Snowpack Summary

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.

Problems

Persistent Slabs

An icon showing Persistent Slabs
Persistent slabs are most likely to be triggered from thin snowpack areas, or with large triggers like cornice fall or an avalanche stepping down.
Avoid common trigger points like convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 6

Wind Slabs

An icon showing Wind Slabs
Wind slabs may be lurking on lee and cross-loaded features in the alpine. Cornices are weak and may collapse.
Be cautious as you transition into wind affected terrain.>Give cornices a wide berth when travelling on or below ridges.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Loose Wet

An icon showing Loose Wet
Direct sun may weaken the snow surface, causing a spike in avalanche activity on steep sunny aspects.
Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: North, North East, East, South East.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Feb 15th, 2015 2:00PM