Vancouver Island Avalanche Bulletin

Vancouver Island Avalanche Bulletin

Date Issued: Thursday, March 12, 2009

Valid Until: Sunday March 15, 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 to good - exact amounts of precipitation are uncertain.

Primary concerns:

Increasing amounts of new snow and wind transported snow over the week-end creating soft and hard slabs over faceted surface snow and loading persistent weak layers deeper in the snow pack.

Weather:

Clear skies and cold temperatures lasted to mid day Wednesday. Since then freezing levels have risen to tree line and above and will continue to rise later thursday. They will drop again starting Friday making it down to 1000m by Friday afternoon and continue to drop to around 300-500m over the week-end. Snow is forecast to begin lightly some time Friday giving 5 to 10 cm total on Friday. Saturday will bring another 10 to 20 cm followed by an additional 10-20 cm Sunday. Winds will reach up to 35km/hr at times from the South and South East. 

Travel advisory:

With the snow coming slowly at first normal caution is advised on Friday. Keep an eye out for persistent wind slab which in places is overlying persistent instabilities deeper in the snow pack. As the load from new snow and wind transported snow increases over the course of the week-end a natural avalanche cycle will ensue. Stay out of avalanche terrain on Saturday and Sunday. Stick to simple. Low angled and forested terrain and watch out for overhead hazard. Watch the rate of snow fall and increase caution if the snow comes in earlier, in greater than forecast amounts or with stronger winds.

Snowpack:

Much of the surface and near surface of the snow pack at present consists of faceted crystals created by the cold temperatures of past days. These crystals in themselves do not present a hazard but with the additional load which they will receive from new snow and wind transported snow they will likely produce both natural and human triggered avalanches later in the week-end or earlier depending on the rate of the incoming snow. A persistent surface hoar layer from 22 February is well preserved about 70cm down in places in the island snow pack. With loading avalanches may “step down” to this layer producing much bigger slides.

Avalanche Activity:

Sluffing of faceted surface snow has been reported on Wednesday on slopes 40 degrees and steeper.

Outlook:

Snow is forecast to begin lightly some time Friday giving 5 to 10 cm total on Friday. Saturday will bring another 10 to 20 cm followed by an additional 10-20 cm Sunday. Winds will reach up to 35km/hr at times from the South and South East. Freezing levels will drop starting Friday making it down to 1000m by Friday afternoon and continue to drop to around 300-500m over 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.