Avalanche Forecast
Issued: Mar 7th, 2016 8:13AM
The alpine rating is Wind Slabs and Cornices.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate
Weather Forecast
TUESDAY: Mainly cloudy with light to moderate snow â 5-15 cm. The freezing level is around 800 m and ridge winds are moderate to strong from the south. WEDNESDAY: Sunny breaks. The freezing level gradually climbs to 1200-1400 m. Ridge winds are light increasing to strong from the SE. THURSDAY: Periods of snow. The freezing level dips back to 800-1000 m and winds are moderate from the S-SE.
Avalanche Summary
Numerous explosive, machine, and rider-triggered slabs were reported on Sunday. Of note, there were two size 3 slabs. Both occurred on northerly aspects, one was explosive triggered and one was cornice triggered. There was also a report of a size 2 skier triggered wind slab on an exposed west-facing slope at treeline. On Saturday, a size 2 slab avalanche was accidentally triggered on Oscar Peak northwest of Rosswood. The avalanche occurred on a steep roll at about 1400m and is thought to have failed on recently buried surface hoar.
Snowpack Summary
Over the past few days daily snowfall accumulations have generally been in the 5-15cm range with the highest accumulations occurring in the south of the region. Strong to extreme ridgetop winds have shifted the new snow into new wind slabs at treeline and in the alpine adding to an ongoing wind slab problem. About 60cm below the surface you'll likely find a crust that was buried on February 28th. A report from northwest of Rosswood suggests a recently buried layer of surface hoar may also exist in the upper snowpack, although I'm unsure of its size or distribution. An older crust buried in early February can now be found around 80-120cm below the surface. This crust, which may coexist with small facets or decomposing surface hoar, was recently producing sudden planar results in tests. Although no recent avalanches were reported to have failed at this interface, I'd remain suspicious of this layer in steep, unsupported terrain at treeline and in the alpine.The mid pack is generally well settled and strong.
Problems
Wind Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 8th, 2016 2:00PM