Vancouver Island Avalanche Bulletin

Vancouver Island Avalanche Bulletin

Date Issued: Friday 20 November, 2009

Valid Until: Sunday 22 November, 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 - This is the first bulletin of the season and field information remains limited.

Primary concerns:

• New Snow - On average we have had 60cm of new snow in the last 48 hours. Amounts vary considerably from place to place in the island alps.
• Wind - Up to 60kph in the last 24 hours predominantly from the south and south east.
• Wind Slab - The combination of the above factors will produce wind slab particularly in the alpine and at treeline.

Weather:

On average 60cm of snow has fallen on the island mountains in the last 48 hours. Amounts vary from place to place ranging from 35 to 75 cm. Winds were steadily moderate and strong for periods of hours in this time frame. The outlook is for continued precipitation delivering up to 25cm by Saturday morning on the west coast with less on the east, and up to 20 cm more from Saturday afternoon through Sunday morning. Winds are forecast to be moderate SE through SW except for the west coast which will see stronger winds likely from the west on Sunday. Freezing levels should remain at 800m and below.

Travel advisory:

Travel in avalanche terrain is only recommended for people with higher levels of training and experience for the forecast period. Plenty of new snow and wind have formed wind slabs most intensely in the alpine and at tree line. These slabs will be easily triggered by skiers, sledders and snowboarders. Below tree line hazard is less but skiers could still trigger avalanches in places where wind can get at steeper terrain. Be aware that snow amounts may vary considerably from forecast amounts and geographically across the island mountains and consider the hazard as high if greater amounts fall.

Snowpack:

Field information on the snow pack is limited. Rain soaked the snow pack up to about 1600m on the night of 15/16 November leaving a rain crust roughly 70cm above ground depending on terrain and elevation. Tests produce moderate results on top of this crust. Approximately one metre of partially settled snow sits on top of this crust. The amount depends greatly on elevation and location on the island. Above approximately 1600m (again varying greatly with location) no rain has fallen leaving a progressive density snow pack. Wind slab is wide spread in the alpine and at tree line. Keep in mind that this snow has come quite quickly meaning only the lowest portion of the pack is well settled. The snow pack in the alpine on the west coast is predicted to be much deeper than elsewhere on the island but observations are yet to be made.

Avalanche Activity:

No new avalanche activity has been observed however observers have not been in the alpine where natural cycles are certain to have occurred and visibility has been too poor to observe from a distance.

Outlook:

Continued precipitation delivering up to 25cm by Saturday morning on the west coast with less on the east, and up to 20 cm more from Saturday afternoon through Sunday morning. Winds are forecast to be moderate SE through SW except for the west coast which will see stronger winds likely from the west on Sunday. Freezing levels should remain at 800m and below.

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.