Vancouver Island Avalanche Bulletin

Vancouver Island Avalanche Bulletin

Date Issued: Tuesday Feb 3, 2009

Valid Until: Thursday Feb 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:

Good: Lots of operator data over the region and a strong weather forecast over the period.

Primary Concerns:

New snow instabilities; Recent snow fall especially in wind loaded areas and at higher elevations where the freezing levels were low enough to create an instability within the storm.

Wet isothermal snow 30-40cms deep at lower elevations.

Weather:

Models are forecasting warm temps with freezing levels up to 2400m on Tuesday then slowly dropping through the period to around 500m on Thursday. No precip except for light flurries possibly on Thursday.  Winds are expected to remain light-moderate from the south.

Snowpack:

The region saw 30-50 cms of wet snow deposited through Sunday night to Monday afternoon.  This storm arrived with a cold front laying down a layer of cold snow where the following warm front deposited up to 30-40 cms of heavy wet snow on this layer.  This created a highly unstable condition with a widespread avalanche cycle kicking in around mid-day on monday when the temps started to increase.  Avalanches to Sz3 were observed on most aspects at Treeline elevations and above.  Ski triggering this layer was possible and the new snow was highly reactive to ski testing and slope tests.  A small cornice drop by an operator triggered a Sz1 avalanche which in turn remote triggered a Sz 2.5 avalanche in the West Bowl of Mt. Cain.  This layer will gain strength with colder temps as the new snow was becoming rain soaked by the afternoon with the rain working its way into the older snow underneath.  Until we see colder temps though this wet isothermal snow in the upper 50cms will be of concern. Higher elevations will still remain unstable until the new snow settles out as alpine areas received the precipitation in the form of snow and not rain.  Rain was observed up to 1400m.

Travel advisory:

Extra caution is advised in Lee areas and open features in the alpine.  Snow has been deposited by the wind into thick windslabs up to 50cms thick which will be reactive and easily ski triggered over the next few days.

Treeline features lee to the wind have also been highly reactive to skiing and slope tests with reports of skier controlled avalanches on monday at this elevation.  All of the island ski areas are at Treeline elevation where there are many areas where a small avalanche can easily sweep you into the trees or over small cliffs.  With high freezing levels the surface layers of the snow will be isothermal in many areas. Isothermal snow is very weak and wet slabs can often be triggered when the snow is in this condition.  If you are post holing past your shins in wet slop this is a good indicator of potentially unstable snow.

Caution is still advised in alpine areas with respect to the xmas facet layer.

Avalanche Activity:

Natural avalanche cycle on Monday afternoon up to Sz 3. Skier controlled and slope tests such as cornice drops producing avalanches up to Sz 2.5

Outlook:

Warm temps and flurries with a low possibly spooling up to hit the island on Friday.

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.