Avalanche Forecast
Issued: Nov 30th, 2012 9:30AM
The alpine rating is Storm Slabs and Deep Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Poor - Timing, track, or intensity of incoming weather is uncertain for the entire period
Weather Forecast
The deep low pressure system off the Gulf of Alaska continues to spin a moist, warm southwesterly flow over the South Coast mountains. The weather pattern will remain continuous and active through the forecast period. Saturday: FLVLâs 1200 m, snow amounts 10-15 cm, ridgetop winds SE 40-50 km/hr, alpine temps near -4.Sunday: FLVLâs 1200m, snow amounts 5-10 cm, ridgetop winds S 10 km/hr, alpine temps -4.Monday: FLVLâs 1100 â 1400m, snow amounts 5-10 cm ridgetop winds S 35 km/hr, alpine temps -5.
Avalanche Summary
Explosive testing produced numerous size 1-1.5 slab avalanches on NW-N aspects. All instabilities reacting within the storm snow.
Snowpack Summary
The region will continue to see moderate amounts of new snow, and strong SW winds. Storm slabs and fresh wind slabs will load a variety of weak surfaces. These (now buried) surfaces consist of large surface hoar, a thin sun crust, and surface facets. Below this, the mid-pack seems to be fairly settled, strong and bridging instabilities that may exist deeper.Under the mid-pack (90-150 cm down) sits the early November facet/ crust persistent weakness. Recent snowpack tests have shown sudden collapse (or "drops") results on the early November facet/crust deep persistent weakness, but because this weakness is so close to the ground in most areas, associated avalanche activity will likely be limited to slopes with smooth ground cover (e.g. scree slopes, rock slabs, summer firn, glaciers, etc.). Areas that are most susceptible to trigger this deep persistent weakness are shallow, thin and variable snowpack deposition spots.To view a recent snow pit profile from the Spearhead Range, check out the Wayne Flann Avalanche Blog.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 1st, 2012 2:00PM