Avalanche Forecast
Issued: Feb 28th, 2013 8:57AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
pgoddard,
Avalanche Canada
Summary
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period
Weather Forecast
Thursday night: Around 15 cm snow. Strong SW winds. Freezing level around 600 m. Friday: Light snow. Moderate to strong S winds. Freezing level around 700m.Saturday: Light snow. Light winds. Freezing level dropping to valley floor. Sunday: No snow expected. Light winds. Freezing level at sea level.
Avalanche Summary
Natural avalanches to size 2.5 were triggered by wind loading on lee alpine slopes on Wednesday. Skiers also triggered smaller wind slabs at treeline.
Snowpack Summary
Strong SE to NE winds have created widespread new wind slabs at treeline and above. A layer of surface hoar, facets and/or a crust is buried down about 30-60 cm and has become reactive in areas with enough of a slab above. A deeper interface, now buried about 1 m or more deep, still has the potential for step-down triggering. It’s been observed in the Shames backcountry with hard “pops” results in snowpack tests. Large cornices loom as a threat, as they could act as triggers for avalanches on slopes below. Mid and lower snowpack layers are generally well settled and strong. The exception seems to be the Bear Pass area where basal facets are still reported.
Problems
Storm Slabs
Recent storm snow will need some time to stabilize. It may be most sensitive to triggering on wind-loaded slopes.
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 1st, 2013 2:00PM
