Vancouver Island Avalanche Bulletin

Vancouver Island Avalanche Bulletin

PARTY FOR THE BULLETIN! Don’t miss the Vancouver Island Avalanche Bulletin Fund Raising Party 24 January, 2009 at the Riding Fool Hostel in Cumberland. Two great bands, prizes, silent auction items and beer from our friends at Phillp’s Brewing. If you use the bulletin and would like to support it, come on out and party! Call 250 336 2870 or email info@islandalpineguides.com for more info.

Date Issued: Monday, December 29, 2008

Valid Until: Wednesday, December 31, 2008

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

Weather: The Last storm cycle that rolled through the region brought dramatically less snow than initially forecasted.  With only around 10cms at Treeline and a bit more in the alpine we are still in need of more snow!

Currently it looks like we are in a nice zonal flow over the next few days with low pressure systems lined up off shore.  The first system is upon us on Sunday night and is forecasted to bring about 15cms with it accompanied by increasing winds through the night up to 70kms/hr from the SE.  Another system is expected for Tuesday night bringing with it possibly another 30cms of snow to the mountains with gale force winds from the SE.  Although a ways off we might be in for another nice big system for Thursday.

Freezing levels are expected to stay low thus resulting in snow to all elevations in the mountains.

Snowpack: Variability is the order of the day in the mountains.  Forecasters in the field on Sunday observed snow heights from avg. 40cms to the odd pocket of wind blown 50-60cms. Many Treeline areas are still below threshold and even the alpine is looking a little bony.  Observations outside of the Mt. Washington boundaries and in the Forbidden Plateau areas are showing about 40cms on average.  Deeper areas exist but mostly due to wind transport.

Of major note is the existence of a surface hoar layer (Dec 25 layer) that is reactive to ski testing.  On Sunday it was possible to trigger this layer easily in areas that have had enough wind to do 2 things; transport enough snow to create deeper pockets and to form a surface slab that rests on the surface hoar. Additional load on this layer will cause natural activity.  This layer is however highly variable and is not found widespread over terrain.  Many areas are below threshold in respect to this layer.

As of Sunday afternoon surface hoar up to 5mm was observed on the surface of the snow.  This was being buried by the snow fall that began around this time & started with calm winds and intense snow fall.  This layer could be a concern with enough load on it as it is higher in the snowpack where the effects of the trees and stumps etc will have little anchoring effect.  Lots of new snow is in the forecast  over the next week with high winds associated.

The facet layer that was observed at Mt. Cain earlier last week was observed in the forbidden Plateau area also but more isolated and closer to the ground where the anchoring effect of ground cover will kick in. The big issue with this layer is in smooth ground cover or where the facet / crust interface is higher off the ground.  Skier triggered avalanches on this layer have been reported with avalanches being easily triggered on the facets on the crust.

Travel advisory: Rock skis!  Lots of rocks and stumps lurking under the surface everywhere.  Hopefully we get all the snow forecasted over the next few days.  Use normal caution on Monday and Extra Caution on the proceeding days as intense snow and high winds load the start zones and lee features.

Although it hurts to say, back country skiing is not a great idea right now.  We need another meter to protect us from the hazards below and help create some uniformity in the snowpack.

Outlook: Big low pressure systems spooling up for the Thursday to Saturday time frame.

Confidence: Fair. Precip amounts are conflicting within wether models. This forecast has gone with the average of the precip forecated.

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 Alpine Guides Avalanche Bulletin.

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.