Avalanche Forecast

Issued: Mar 9th, 2014 8:49AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs and Persistent Slabs.

Peter, Avalanche Canada

Northwest Coastal.

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain on Tuesday

Weather Forecast

Monday: Cloudy with flurries in the morning followed by sunny breaks. The freezing level is around 800-1000 m. Winds are moderate from the W-SW. Tuesday: Periods of snow, heavy at times 20-40 cm (higher amounts are for Bear Pass). The freezing level is around 1200-1400 m and winds increase to strong from the SW. Wednesday: Periods of snow. The freezing level is around 1000 m. Winds remain strong from the SW.

Avalanche Summary

Numerous natural loose wet avalanches up to size 2 were reported below treeline from warming temperatures and rain. There were also reports of many size 2-3 slab avalanches from higher elevations on a variety of aspects. Most of these seemed to release within the recent storm snow or on the previous snow surface buried on March 7.

Snowpack Summary

The snow keeps piling up! Around 50-80 cm of recent storm snow now sits on previous snow surface of hard wind slabs or scoured slopes in exposed terrain and a thick layer of faceted snow on sheltered shady slopes, maybe with some surface hoar mixed in, and a sun crust on steep solar aspects. Expect moist or wet snow below 1000 m, possibly with one or two new crusts near the surface. The mid February weak layer of surface hoar or a crust/facet combo is buried 90-150 cm deep. This layer continues to react in snowpack tests, primarily on sheltered north aspects at or below treeline. Basal facets and/or depth hoar remain a concern in shallow snowpack areas in the northern part of the region.

Problems

Storm Slabs

Weaknesses may exist within the new storm snow (up to 80 cm), or at the interface between the storm snow and old snow surface, which was a mix of sugary facets, a melt-freeze crust, or old hard wind slabs.

Use conservative route selection, stick to moderate angled terrain with low consequence.>Be alert to conditions that change with elevation and use caution in wind loaded northwest to east facing terrain. >

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 6

Persistent Slabs

There is potential for heavy loads like a cornice fall or a storm slab avalanche to step down and trigger a deeper persistent weak layer, down over a metre in most places.

Avoid lingering in runout zones.>Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

3 - 7

Valid until: Mar 10th, 2014 2:00PM