Vancouver Island Avalanche Bulletin

Vancouver Island Avalanche Bulletin

Date Issued: Thursday, March 26, 2009

Valid Until: Sunday March 29, 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: While previously created wind slabs are likely settling in, more recently created slabs on the southerly aspects as well as new slabs which will form with forecast snow and wind will be triggerable by humans in specific locations.
• Storm Snow: Exactly how much will fall is debatable but in sufficient amounts and with wind it will become a problem.
• Persistent weaknesses: Recent avalanche activity suggests that instabilities deeper in the snow-pack can be “woken-up” in specific locations with sufficient load.

Weather:

5 to 15cm of snow has fallen over the island mountains in the last three days. The snow was accompanied by winds which reached moderate for a short times first from the SW on Tuesday then from the NW on Wednesday. Otherwise winds were generally light. Freezing levels stayed below 1000m. More snow is forecast for late Friday and early Saturday though models differ on exact timing and amounts of precipitation. 10-30cm of snow are likely, accompanied by light to moderate winds. Freezing levels should stay below 1000m dropping all the way to sea level later Saturday and then coming back with up with more light snow by later Sunday.

Travel advisory:

Hazard will depend on the amount of snow we actually get and how much wind comes with it. If precipitation amounts are in the upper end of what is forecast here, hazard will be considerable in the alpine and at tree line. Hazard will be greater if more snow falls and/or there is more wind. Only people with extensive training and experience should consider travel in avalanche terrain in these conditions.

Snowpack:

5 to 15 cm of snow over the last three days has formed wind slab in places and overlies wind slab on all aspects from previous storms. Surfaces snow became wet on solar aspects on Wednesday causing some balling. This will have re-frozen by now. Crust and facet layers exist deeper in the snow-pack as persistent weaknesses.

Avalanche Activity:

A significant size two avalanche has been reported on a north east aspect just above tree line. The avalanche likely happened during the cycle last week-end and is significant because it seems to have failed deeper in the snow pack on a persistent weak layer supporting the idea (prevalent all over the south coast these days) that persistent weaknesses deeper in the snow pack may be “waking up” at present.

Outlook:

Snow is forecast for late Friday and early Saturday though models differ on exact timing and amounts of precipitation. 10-30cm of snow are likely, accompanied by light to moderate winds. Freezing levels should stay below 1000m dropping all the way to sea level later Saturday and then coming back with up with more light snow by later Sunday.

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.