Avalanche Forecast

Issued: Dec 6th, 2017 9:41PM

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

Dan Goodwin, VIAC

Vancouver Island.

Summary

Confidence

Moderate - no alpine snow pack observations and most obersvations limited to Eastern Central Vancouver Island.

Travel/Terrain Advice

Very high temperatures and freezing levels and no overnight freezing of upper snow pack will result in very moist to wet snow that provides little support to travelers. Be aware that even small loose wet avalanches can push one into or over terrain traps such as depressions, cliffs, and trees. There is potential for large to very large avalanches starting in treeline and alpine terrain to impact below treeline elevations. Use caution when crossing large avalanche paths in all elevations. Watch for early season hazards such as exposed creeks, stumps, and tree wells especially below treeline.

Past Weather

Vancouver Island has seen little to no precipitation, light to moderate SW through SE winds and temperatures ranging from -7oC to +6oC. Freezing levels across the forecast region have ranged from sea level to 2300 m.

Avalanche Summary

Loose wet avalanches at treeline and below treeline on exposed solar aspects with pinwheeling and tree bombs.

Snowpack Description

Surface - Thin unsupportive melt freeze crust on solar aspects at all elevation, in some shaded areas snow remains cold Upper - Wind loaded pockets bonding moderately to an upper crust on NW-NE aspects at treeline and alpine. Scoured and pressed surface on windward slopes exposing the crust Mid - Well settled crust complex Lower - Well settled

Weather Forecast

Temperatures and freezing levels will remain high with potential freezing levels of up to 3600 m with the persistent high pressure system. Expect a temperature inversion for the duration of the forecast period with low level clouds and morning fog near the ocean. Wed - No new snow. Winds light SE Freezing level to 2800-3600 m Thur - No new snow. Winds light to moderate SE Freezing level to 2500-3600 m Fri - No new snow. Winds light to moderate SE Freezing level to 1200-3600 m

Problems

Loose Wet

Rising temperatures and freezing levels are likely/very likely to produce avalanches from small to large, especially on solar aspects at all elevations.

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 3

Wet Slabs

Recent storm snow and wind loaded areas overlying the upper rain crust are likely to produce wet slab avalanches with the forecasted warming. These avalanches have the potential to be large/very large in the upper treeline to alpine.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Dec 8th, 2017 6:00PM