February 13, 2008
Whistler Avalanche conditions
February 13, 2008
Alpine: Considerable
Treeline: Moderate
Below Treeline:Low
Travel Advisory: A series of storms have swept through our region depositing approximately 66cm of snow during the past week. Winds accompanying the bulk of the snowfall since Feb 7th have been strong. The freezing level on Saturday rose to 1700m and some areas experienced periods of freezing rain mist. Wind exposed slopes will be scoured, while you can expect to find some soft windslabs in lee terrain and around terrain features on more North facing aspects. Cornices have grown and are fragile so give them a wide berth from both above and below. Keep in mind that a slab avalanche triggered within the storm snow has the potential to step down to deeper instabilities in the snowpack.
Avalanche Activity: Explosive and ski testing this morning was producing mostly size 1.0 to 1.5 soft slabs with crowns up to 20cm in depth, stepping down deeper to earlier storm snow layers in some isolated areas. Cornices were observed to be very reactive with some large cornice falls triggered with small bombs. The most recent activity on the Dec 04 Crust and facet layer was on January 21st and was initiated by a large cornice fall.
Snowpack: The strong winds have created a wide variety of conditions in the alpine and treeline terrain. You will find pockets of soft windslab, scoured surfaces, and areas of less wind affected new snow as you descend closer to the treeline. Below the new snow layers are several layers of buried windslab, as well as old hard wind-hammered surfaces. You may also feel a weak ice lens that developed with the freezing mist on Saturday. At treeline and below treeline elevations several surface hoar and facet layers are now buried anywhere from 40-80cm in depth. Now that these layers have received a critical load, there have been reports of whumphing and cracking on some treeline slopes, as well as isolated skier triggered avalanche activity on the most recent surface hoar layer. The December 4th raincrust and facet crystal weakness is well buried in most areas, and although it has gradually been gaining strength, it has continued to pop up sporadically. Its unpredictable and persistent nature has been problematic and backcountry travelers should continue to be cautious. The deep slab releases have generally appeared to initially fail in a shallow part of the slab in rocky start zones, propagating into the deeper areas.
Weather: Mainly sunny skies should prevail today, with increasing cloud cover tomorrow on the approach of a weak system. Periods of flurries are expected to persist right thru the weekend with sunny breaks inbetween.
February 13, 2008
Alpine: Considerable
Treeline: Moderate
Below Treeline:Low
Travel Advisory: A series of storms have swept through our region depositing approximately 66cm of snow during the past week. Winds accompanying the bulk of the snowfall since Feb 7th have been strong. The freezing level on Saturday rose to 1700m and some areas experienced periods of freezing rain mist. Wind exposed slopes will be scoured, while you can expect to find some soft windslabs in lee terrain and around terrain features on more North facing aspects. Cornices have grown and are fragile so give them a wide berth from both above and below. Keep in mind that a slab avalanche triggered within the storm snow has the potential to step down to deeper instabilities in the snowpack.
Avalanche Activity: Explosive and ski testing this morning was producing mostly size 1.0 to 1.5 soft slabs with crowns up to 20cm in depth, stepping down deeper to earlier storm snow layers in some isolated areas. Cornices were observed to be very reactive with some large cornice falls triggered with small bombs. The most recent activity on the Dec 04 Crust and facet layer was on January 21st and was initiated by a large cornice fall.
Snowpack: The strong winds have created a wide variety of conditions in the alpine and treeline terrain. You will find pockets of soft windslab, scoured surfaces, and areas of less wind affected new snow as you descend closer to the treeline. Below the new snow layers are several layers of buried windslab, as well as old hard wind-hammered surfaces. You may also feel a weak ice lens that developed with the freezing mist on Saturday. At treeline and below treeline elevations several surface hoar and facet layers are now buried anywhere from 40-80cm in depth. Now that these layers have received a critical load, there have been reports of whumphing and cracking on some treeline slopes, as well as isolated skier triggered avalanche activity on the most recent surface hoar layer. The December 4th raincrust and facet crystal weakness is well buried in most areas, and although it has gradually been gaining strength, it has continued to pop up sporadically. Its unpredictable and persistent nature has been problematic and backcountry travelers should continue to be cautious. The deep slab releases have generally appeared to initially fail in a shallow part of the slab in rocky start zones, propagating into the deeper areas.
Weather: Mainly sunny skies should prevail today, with increasing cloud cover tomorrow on the approach of a weak system. Periods of flurries are expected to persist right thru the weekend with sunny breaks inbetween.
