Vancouver Island Avalanche Bulletin

Vancouver Island Avalanche Bulletin

Date Issued: Friday, March 20, 2009

Valid Until: Sunday March 22, 2009

Bulletin Area: This bulletin covers the mountainous region of Vancouver Island from the Mt. Cain Ski Area in the North to the Beaufort range to the South including the mountains of Strathcona Provincial Park.

DANGER RATINGS

Confidence:

Fair - exact amounts and timing of precipitation are uncertain.

Primary concerns:

• Wind Slab: Winds have been creating both hard and soft wind slab in the lees especially on North and North West aspects as well as cross loading. These slabs will be the scene of natural avalanches and will be triggerable by humans.
• Storm Snow: Fluctuating temperatures and humidity have and will continue create weaknesses within the storm snow which may result in natural or human triggered avalanches on these weaknesses.
• Persistent weaknesses: With heavy loading natural and human triggered avalanches may “step-down” to persistent weaknesses deeper in the snow pack.

Weather:

Between 50cm and over a metre of snow has accumulated over the island mountains since Tuesday. Larger accumulations on the west coast peaks and less on the east. This snow came with winds from the South and South East up to 35km/hr. Some of this precipitation came as rain to the lower elevations at times. The outlook is for continued snow on Friday and Saturday delivering another 20 to 40cm of snow. This snow will be accompanied by South East winds to 30km/hr. Freezing levels will drop below 1000m Friday and continue to drop to hover around 500-700m through the week-end.

Travel advisory:

Plenty of new snow and wind over the last number of days and a continuation of the same for Friday and Saturday mean that our avalanche danger remains high for Friday and Saturday at least. If precipitation and wind ease off on Sunday as forecast the rate of natural avalanches will slow down but human triggered slides will still be probable on Sunday. Avoid avalanche terrain and stick to simple, low angled terrain. Watch out for overhead hazards and either avoid avalanche run out zones completely or cross them quickly and one at a time while watching from safe spots. This is not the week-end to be in avalanche terrain.

Snowpack:

50 to over 100cm of new snow has weaknesses within it and has formed wind slabs both hard and soft particularly on North and North West aspects. Persistent weak layers still exist deeper in the pack with facets layers formed at and near the surface in our last cold spell now buried under 70 to 170cm of snow. With increased load the potential still exist for avalanches to “step down” to these deeper persistent weak layers. 

Avalanche Activity:

Avalanches both natural and human triggered to size 2 have been reported.

Outlook:

Continued snow on Friday and Saturday delivering another 20 to 40cm. This snow will be accompanied by South East winds to 30km/hr. Freezing levels will drop below 1000m Friday and continue to drop to hover around 500-700m through the week-end.

Are you traveling in the island back country?

Send our forecasters your observations. We are particularly interested in hearing if you have observed avalanche activity or If you or a member of your party has been involved in an avalanche. Email your observations to the Island Avalanche Bulletin forecasters at info@islandalpineguides.com

Important Notice: This is a regional forecast and significant variation may exist within the forecast area. The information and danger ratings are intended as a trip planning aid for recreational, backcountry users of avalanche terrain; they are not meant to be used as the sole factor in determining the avalanche danger presented by a specific slope. Always include local weather, snowpack and avalanche observations in your decision to travel in avalanche terrain. Observations and experience may lead to different conclusions from what is reported or recommended. See disclaimer for further details. The technical data used to produce these bulletins is obtained from a variety of sources, including local ski areas and remote weather resources.