Avalanche Forecast
Issued: Nov 28th, 2012 10:26AM
The alpine rating is Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Poor - Due to limited field observations for the entire period
Weather Forecast
A deep low pressure system off the Gulf of Alaska will be bringing a very moist, warm and active weather pattern over the next five days. The system will move into the region Wednesday afternoon, and persist with moderate to heavy amounts of precipitation through the weekend. Thursday: FLVLâs 1400 m, snow amounts up to 25 cm, ridegtop winds SE 40-50 km/hr, alpine temps -4.0.Friday: FLVLâs 1500 m, snow amounts 15-25 cm, ridgetop winds SE 60-gusting 80 km/hr, alpine temps -3.0.Saturday: FLVLâs 1400 m falling 1000 m overnight, 5-10 cm, ridgetop winds S 20 km/hr, alpine temps -3.0.
Avalanche Summary
Check out Wayne Flann's Avalanche Blog for a photo of a recent large avalanche off the north face of Mt. Currie. Natural avalanche activity will pick up again with forecast wind and snow.
Snowpack Summary
New storm slabs will build over a variety of weak snow surfaces. These surfaces consist of large surface hoar, a thin sun crust, surface facets, moist snow, or preserved storm snow depending on elevation, sun and wind exposure, slope angle, time of day, and aspect. The main snowpack feature is a rain crust buried early November and now down around 60-80 cm at treeline. A weak layer of facets sitting on top of this crust shows "sudden" fracture character and the ability to propagate into large avalanches if triggered. Widespread whumpfing and cracking on this layer has also been reported. It's mostly a concern at upper treeline and alpine elevations on slopes with smooth ground cover (e.g. scree slopes, rock slabs, summer firn, grass, etc.). Coquihalla Pass and Cayoosh Pass have around 50cm on the ground at the road elevation. Treeline areas have around 100-120 cm Alpine areas likely have more snow, but also highly variable depths depending on wind exposure. For more information check out the telemarktips.com forum, the Mountain Conditions Report, and Wayne Flann's Avalanche Blog.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 29th, 2012 2:00PM