Avalanche Forecast

Issued: Jan 8th, 2014 8:31AM

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

jlammers, Avalanche Canada

South Coast.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Thursday: Moderate snowfall overnight Wednesday should ease to light accumulations on Thursday / Strong southwest winds / Freezing level at 800mFriday: Light to moderate snowfall overnight Thursday should ease to flurries during the day on Friday / Strong to extreme southwest winds / Freezing level at 900mSaturday: Heavy to very heavy snowfall overnight Friday will continue throughout Saturday morning / Moderate to extreme southwest winds becoming northwest in the afternoon / Freezing level at 1200m falling to valley bottom throughout the day

Avalanche Summary

2 size 2 slab avalanches (human triggered and natural) were observed in Marriott Basin in the Duffey Lake area over the last few days. No injuries were reported. The avalanches occurred around 2100m on south-facing terrain. Both were thought to have ran on a crust/facet interface. Check out our Incident Report Database for more details. No other recent avalanches have been reported.

Snowpack Summary

Snowpack depths at treeline range from 130-170 cm in the South of the region, and from 80- 130 cm in the North of the region. Light amounts of new snow overlie a variety of old surfaces which may include surface hoar in sheltered terrain, wind-pressed snow in exposed areas, or a melt-freeze crust on previously sun-exposed slopes.In the north of the region, recent storm snow is sitting on a weak layer of buried surface hoar which formed in early December. Facets from December's cold snap also seem fairly widespread in this part of the region. In some areas, these facets may co-exist with a crust in the mid pack. In shallow snowpack areas, the facets may exist at ground level. These persistent weaknesses may likely wake-up with new snow forecast for the rest of the week.

Problems

Storm Slabs

Snowfall throughout Wednesday evening will build new and potentially reactive storm slabs. Watch for increased reactivity in wind-exposed terrain.

Be cautious as you transition into wind affected terrain.>Be alert to conditions that change with elevation.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

Snow forecast for the week will create a steadily increasing load to buried persistent weakness which seem most prevalent in the north of the region. Triggering these weaknesses may have nasty consequences.

Use caution on open slopes and convex rolls at treeline where buried surface hoar may be preserved.>Use caution in shallow snowpack areas where triggering is more likely.>Dig down to find and test weak layers before committing to a line.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Jan 9th, 2014 2:00PM