Avalanche Forecast

Issued: Apr 3rd, 2013 9:19AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Persistent Slabs and Cornices.

Avalanche Canada pmarshall, Avalanche Canada

Summary

Confidence

Fair

Weather Forecast

Synopsis: The first in a series of frontal systems will reach the coast on Thursday afternoon spreading light to moderate precipitation to the Northwest through Saturday morning.Thursday: Increasing cloud with light snow developing in the evening. The freezing level rises to 1500 m during the day and winds are generally light from the southwest. Friday: Moderate precipitation – 10-15 cm. The freezing level is near 1200 m and winds are moderate from the south. Saturday: Light precipitation continues. The freezing level remains around 1000 m.

Avalanche Summary

Solar induced avalanche activity decreased on Tuesday with the arrival of cooler temperatures. There were new reports of glide slab releases up to size 3.5 in steep open terrain at lower elevations, and isolated cornice failures at ridgetop.

Snowpack Summary

Surface snow has settled with the influence of warm temperatures and surface faceting continues on steep shaded slopes. Solar aspects in the alpine and all lower elevation terrain are now well into a daily melt-freeze cycle with sun-exposed slopes becoming very weak with daytime warming.Between 50-75cm below the surface is layer of surface hoar buried on March 9th which is variably reactive. In some areas it is stubborn and requires a significant trigger. In other areas the layer is still well preserved showing sudden planar or sudden collapse test results, and remains a primary concern among some professional operators.The mid snowpack is generally well settled and strong. Having said that, basal facets may resurface as a concern with spring warming, particularly in the north of the region. Cornices are large and untrustworthy, especially when the sun is out.

Problems

Persistent Slabs

An icon showing Persistent Slabs
Recent reports of remote triggering suggest the March 9th surface hoar layer is still touchy in some areas. Where it is still reactive, avalanches can be large and potentially destructive. Also, give gaping glide cracks a wide berth.
Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>Dig down to find and test weak layers before committing to a line.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 5

Cornices

An icon showing Cornices
Large developed cornices loom over slopes. A cornice fall has the potential to initiate large avalanches.
Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 6

Valid until: Apr 4th, 2013 2:00PM