January 12, 2008
Whistler Avalanche conditions
January 12, 2008
Alpine: Considerable
Treeline: Considerable
Below Treeline: Moderate
Travel Advisory: Expect to find easily triggered 30 centimeter slabs on lee slopes, especially in sheltered terrain below large features. Exposed alpine terrain is harbouring some stiff wind slab that is also reactive to skier traffic. The potential for skiers to trigger the persistent deep instability in the snowpack from shallow weak spots is an important point to consider. The natural avalanche cycle that occurred last weekend left large debris piles beyond normal runout zones. Monday's forecast heavy precipitation coupled with a brief cold snap on Tuesday should prove a significant test of the deep instability.
Avalanche Activity: Easily triggered size one and two slab avalanches were widespread yesterday. Some of these slabs were stiff 30 centimeter windslabs that propagated easily across long distances. A significant natural avalanche cycle up to size 3.5 occurred during the storm throughout the South Coast region. A size 3 accidentally skier triggered avalanche on Sunday occurred in the ski area on a NE aspect after explosive testing and ski cutting failed to trigger any result. The crown was 3.75 meters deep and 75 meters wide and was determined to have run on the December 4th rain crust.
Snowpack: 15 to 40 centimeter slabs varying from soft four finger to stiff one finger windslab are widely distributed throughout the alpine and into treeline. This surface slab is shearing easily. Last week's storm snow is a deep and relatively uniform layer now that it has had time to settle. The December 4th facet-crystal and raincrust weakness is buried up to 3.75m deep in some lee features but on average it's 1.5-2.5m deep. Although this buried weakness has gradually been gaining strength, we continue to see significant results on this layer on all aspects.
Weather: A weak system will bring some more snow to our area through Saturday. The next big system is forecast to slam into our area on Monday bringing heavy precipitation and relatively mild temperatures. This will probably be followed by significantly cooler temperatures on Tuesday before mild high pressure sets up on Wednesday.
January 12, 2008
Alpine: Considerable
Treeline: Considerable
Below Treeline: Moderate
Travel Advisory: Expect to find easily triggered 30 centimeter slabs on lee slopes, especially in sheltered terrain below large features. Exposed alpine terrain is harbouring some stiff wind slab that is also reactive to skier traffic. The potential for skiers to trigger the persistent deep instability in the snowpack from shallow weak spots is an important point to consider. The natural avalanche cycle that occurred last weekend left large debris piles beyond normal runout zones. Monday's forecast heavy precipitation coupled with a brief cold snap on Tuesday should prove a significant test of the deep instability.
Avalanche Activity: Easily triggered size one and two slab avalanches were widespread yesterday. Some of these slabs were stiff 30 centimeter windslabs that propagated easily across long distances. A significant natural avalanche cycle up to size 3.5 occurred during the storm throughout the South Coast region. A size 3 accidentally skier triggered avalanche on Sunday occurred in the ski area on a NE aspect after explosive testing and ski cutting failed to trigger any result. The crown was 3.75 meters deep and 75 meters wide and was determined to have run on the December 4th rain crust.
Snowpack: 15 to 40 centimeter slabs varying from soft four finger to stiff one finger windslab are widely distributed throughout the alpine and into treeline. This surface slab is shearing easily. Last week's storm snow is a deep and relatively uniform layer now that it has had time to settle. The December 4th facet-crystal and raincrust weakness is buried up to 3.75m deep in some lee features but on average it's 1.5-2.5m deep. Although this buried weakness has gradually been gaining strength, we continue to see significant results on this layer on all aspects.
Weather: A weak system will bring some more snow to our area through Saturday. The next big system is forecast to slam into our area on Monday bringing heavy precipitation and relatively mild temperatures. This will probably be followed by significantly cooler temperatures on Tuesday before mild high pressure sets up on Wednesday.
