Vancouver Island Avalanche Bulletin

Vancouver Island Avalanche Bulletin

Date Issued: Friday. April 17, 2009

Valid Until: Sunday. April 19, 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:

Good - For Friday and Saturday but weather models are conflicting for Sunday for precip amounts.

Primary concerns:

• Wet snow avalanches on all aspects up to Treeline until Saturday then into the alpine on Sunday as the freezing levels rise
• New snow instabilities such as wind slab due to new snow and high winds.

Weather:

Freezing levels will rise up to 2800m over the next few days as the the next 2 low pressure systems roll over us.  High levels of precip are expected in the form of rain at Treeline and below elevations up until Saturday.  On sunday the FZL’s will spike to 2800 where any precip will be in the form of rain to the tops of the mountains.

Travel advisory:

Tis the season for large climax avalanches on the Island as the rain soaks the snow pack and works its way down to the lower weakness and to the ground.  Be aware of avalanche start zones high above you and watch for the conditions turning isothermal if not allready.  With these high freezing levels its just not the solar aspects we need to worry about.  Lee loaded slopes on Friday and Saturday will be a concern as the new snow loads from the winds.

Snowpack:

Our main concerns right now in the snowpack are the isothermal conditions at the lower elevations and new wind slabs overlying meltfreeze crusts in the alpine.  The system that came in on Thursday  brought lower temps and new snow with it.  Expect this new snow to bond poorly to old crust layers and to become loaded with warmer moist snow as the storms track over us.  This snow will be easily reactive to skier triggering.  Isothermal conditions were observed up to 1200m on Thursday to at least a meter deep and to the ground at the lower elevations.  On steep slopes at tree-line elevations especially those with smooth ground cover such as rock slabs natural activity will be expected with the additional rain that is forecasted.

Most areas below treeline are now below threshold with not enough snow to avalanche BUT that does not mean you are safe from large avalanches that could come thundering down from above.  In spring large climax avalanches often run their full paths.

Avalanche Activity:

No new avalanches have been observed over the last 72hrs.

Outlook:

A wet weekend in store for us with high FZL’s.  More rain on the way on Monday possibly.

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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.