Avalanche Forecast

Archived

Feb 18th, 2012–Feb 19th, 2012

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Sea To Sky.

Confidence

Good

Weather Forecast

Sunday: Trace amounts of snow with some clearing / light northwest winds / freezing level @ 900m Monday: trace amounts of snow / moderate westerly winds / freezing level @ 800m Tuesday: trace amounts of snow / strong northwest winds / freezing level @ 1100m

Avalanche Summary

Widespread natural, human triggered, and explosive triggered avalanche activity was observed in the Whistler area on Saturday. The avalanches were up to size 2 and occurred in response to Friday night's storm.

Snowpack Summary

Heavy snowfall and strong winds on Friday night created new wind and storm slabs and continued to cover an assortment of old snow surfaces that were first buried a little over a week ago. These old surfaces are now about 45cm down and include crusts that exist on all aspects at lower elevations and on steep solar aspects higher up. There are also surface facets on northern aspects where colder temperatures have persisted. Facets and spotty surface hoar may also exist in combination with crusts. The mid and lower snowpack are strong and well settled. The average treeline snowpack depth is about 240cm.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.