Vancouver Island Avalanche Bulletin

Tickets are on sale now for the Fourth Annual Party for the Bulletin. Don't miss your chance to attend this now legendary event with live music, silent auction and lots of fun. This is the thing that keeps your source of avalanche info going so come out in support. It all happens at the Riding Fool Hostel in Cumberland on Friday 27 January. More info here.

BULLETIN UPDATE Friday 20 January, 2012, 10:30.

Latest runs of weather models this morning show that precipitation may be slightly less than predicted in the forecast below. This does not change our hazard ratings because snowfall amounts remain great enough and winds strong enough that there is no significant change to this forecast. The Hazard will be high out there this week end and forecasters are concerned that after an extended period of a lack of snow the public will be keen to get out into the fresh powder this week end. You can still get out there but are strongly advised to stay out of avalanche terrain. See the travel advisory below.

We have also refined our freezing level forecast for Friday.

Valid Until: Sunday 22, 2012.

Confidence:  Good. Except that there is some uncertainty re freezing levels for Friday/Saturday. Hazard ratings above are for areas of highest precipitation.

Main Concerns: (Avalanche problems)

Wind Slab - Strong to very strong winds will move great amounts of snow forming widespread and easily triggerable wind slabs at tree line and in the alpine.

Persistent Slab - Both surface hoar in places sheltered from wind at tree line and below as well as a thin crust with loose snow beneath at tree line will be the failure planes for avalanches with the significant load of forecast snow and wind.

Storm Slab - With significant snowfall amounts and variations in temperature in the forecast, weaknesses will exist within the storm snow.

Weather:

The island alps received 5 to 10 cm of very low density snow over the last couple of days. Winds were light gusting to moderate from the NW through to the SW. Temperatures remained very cold by island standards ranging from -7 to -19 at tree line. The Outlook is as follows:

Friday: 35 to 70 cm of snow (most on the west island). Winds strong and mostly SE through to SW. Freezing levels are difficult to predict at present but appear to be rising to somewhere between 1000m and 1500m. Watch this bulletin for an up date on Friday. Friday Update: Freezing levels will likely rise to about 1500m overnight Friday/Saturday and then settle back to around 1000m on Saturday.

Saturday: 10 to 35cm of snow. Strong SE to SW winds. Freezing levels ranging from 500 to 1000m.

Sunday: 30 to 45cm of snow. Strong to very strong SE to SW winds. Freezing levels around 900m.

Snow Pack:

The island snowpack varies quite a bit from the east coast to the west and north island and is more complex in the alpine than many are accustomed to seeing on the island. Snow pack conditions described below may or may not apply exactly to the area that you are in so local investigation is important.

New wind slab has formed in the alpine and at tree line from winds NW to SW and is likely triggerable by human loads. A weak layer of surface hoar likely persists in places sheltered from the wind at tree line and below. A thin crust with very loose snow beneath exists at tree line and will likely collapse under the load of the forecast new snow . The mid pack is strong. The early November crust/facet layer previously reported is likely only triggerable with large loads such as cornice fall and in very specific shallow, rocky, cold terrain in the alpine only.

Avalanche Activity:

Some small soft slabs to size one but with little mass were ski cut on Wednesday. No natural avalanche activity has been observed. A widespread natural avalanche cycle is expected in the coming forecast period.

Travel Advisory:

When hazard is this high the best way to avoid being caught in an avalanche is to stay out of avalanche terrain. Stick to low angled and well forested areas and stay away from wind effected areas.

Prepared by Jan Neuspiel