Vancouver Island Avalanche Bulletin

Vancouver Island Avalanche Bulletin

Date Issued: Thursday, April 2, 2009

Valid Until: Sunday April 5, 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 - Weather models seem to agree but field information is limited for this forecast.

Primary concerns:

• Wind Slab: Strong winds from all directions but particularly from the NW on Tuesday and Thursday and the SE on Wednesday have left deep wind slabs on most aspects.
• Solar Radiation: With freezing levels rising dramatically and strong spring sun shine sunny southerly slopes will experience decreasing snow stability through the day increasing the chances of both natural and human triggered avalanches.

Weather:

Since Monday evening 20 to 50cm of new snow has fallen on the island mountains with the higher amounts being limited to the west coast. Tuesday saw NW winds of up to 60km/hr, Wednesday SE winds to 35km/hr and Thursday NW again to 50km/hr. Freezing levels stayed below 1000m for the period, well below for much of it. The outlook is for a high pressure ridge to bring mostly sunny skies for the forecast period. Freezing levels will rise quite quickly starting as low near sea level Thursday night, getting to 1000m by Saturday morning and over the tops of the island mountains by Saturday evening. Expect temperatures above freezing at 1000m on Saturday and up to 5 at 1000m on Sunday. Winds will remain moderate to strong from the NW to this evening and then ease off remaining light for the remainder of the forecast period.

Travel advisory:

On Friday the main concern is the wind slabs which will have been laid down on all aspects by the winds which have been strong particularly from the NW and the SE. Caution is advised in avalanche start zones at ridge top as well as in cross loaded features. Things will improve on Saturday as time and warm (but not yet too warm) temperatures settle out these slabs but watch out for when the rising freezing levels and intense spring sunshine will quickly destabilize snow especially on Sunday.

Snowpack:

First strong NW winds Tuesday then strong SE winds Wednesday followed by strong NW winds again Thursday have had plenty of snow to move around with what was already there plus 20-50cm of new snow. Wind slabs on all aspects are the result. Below these slabs lies a relatively solid snow pack in which it would appear the deeper persistent weaknesses have strengthened.

Avalanche Activity:

There are no new avalanche observations to report.

Outlook:

High pressure ridge to bring mostly sunny skies for the forecast period. Freezing levels will rise quite quickly starting as low as near sea level Thursday night, getting to 1000m by Saturday morning and over the tops of the island mountains by Saturday evening. Expect temperatures just above freezing at 1000m on Saturday and up to 5 degrees at 1000m on Sunday. Winds will remain moderate to strong from the NW to this evening and then ease off remaining light for the remainder of the forecast period.

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.