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: Friday, January 9, 2009

Valid Until: Sunday, January 11, 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.

SPECIAL GUIDANCE FOR AMATEUR RECREASTIONISTS:

Travel in avalanche terrain at and above tree line is still not advisable. Differentiating between safe and unsafe terrain will be very difficult even with a high level of training and experience. With the very terrain specific hazard that exists at present do not be fooled by the Moderate rating for Friday.

DANGER RATINGS

Weather: The warming and precipitation of Tuesday and Wednesday has had dramatically varying effect in the island mountains. Whereas the west coast of the island received more than 100mm or rain or water equivalent snow, the east cost has seen less than 10mm in places. Freezing levels rose to the tops of the island mountains everywhere at some point over the last days but in many places (especially the further east you head) this was more short lived.

Snowpack: Variability remains the only constant in the island snow pack. There has certainly been a widespread avalanche cycle acrross the island mountains. Up to size 2 has been reported on the east coast and though we do not have reports from the western part of the mountains, with the quantity of precipiation that fell it is a cerainty that there were avalanches.

It is likely that with the massive precipitation amounts seen on the west coast the deep instabilities in the snow pack there will have caused widespread avalanching and as such may have made things considerably safer on that side. As one moves east in the island mountains the picture appears to have been quite different. There is less evidence of widespread natural avalanching in the eastern mountains. Snow profiles done on the east side of the island have shown the unstable facets deep in the snow persisting and rendering moderate results in tests.

While this deep facet layer may well be slowly improving it remains quite loose and sits below a well consolidated mid snow pack. In some place this well consolidated mid pack may effectively bridge the weakness below. in other places if a load is placed in just the right spot (typically a shallower weak spot with smooth ground cover) a fracture might propagate very effectively through the solid mid pack making for significant avalanches.

Below tree line the snow has either been saturated to the ground at lower elevations and subsequently frozen or it is well settled by the warm temperatures making for little concern until new snow and then rain accumulate on top of it on Friday and Saturday respectively.

Travel advisory: Caution is advised on Friday especially the further east you go in the island mountains in the alpine and at tree line in areas of smooth ground cover and were weaker, shallower snow could trigger a propagating fracture into deeper denser slabs. Where you can start an avalanche is very terrain specific but you can start an avalanche. Unless you have very detailed and specific knowledge of the ground cover in terrain you must treat all alpine and sub alpine avalanche terrain as suspect. On Saturday new snow and wind will make newly formed slabs a concern in the alpine and at tree line. Depending on snow amounts caution may be warranted below tree line as well on steeper features especially if terrain traps exist below. Rain later on Saturday and into Sunday followed by a continuing rise in freezing levels will add load to the snow pack. Increased caution in steeper terrain is advised at all elevations on Sunday.

Outlook: Snow on Friday and early Saturday changing to rain later Saturday. Precipitation amounts will likely vary considerably from the west to the east coast of the island with as much as 120mm water on the west coast and perhaps 40-50mm on the east. Freezing levels will rise steadily through the forecast period turning snow to rain in the mountains starting later Saturday. Light to moderate S to SE winds with the snow on Friday and Saturday easing to light on Sunday.

Confidence: Fair. Precip amounts and timing of the rise of the freezing level are approximate.

Special note: Thanks to the members of the North Island Snow Mobile Association who helped out with quick access for our forecaster to get into a specific alpine location yesterday.

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.