Avalanche Forecast

Issued: Mar 14th, 2013 11:08AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Wind Slabs.

Avalanche Canada ghelgeson, Avalanche Canada

Summary

Confidence

Fair

Weather Forecast

Synopsis:  The true pineapple breaks down Friday and a more zonal flow builds in its place.  The North Coast will see a bit more precip than the South Coast, but the amounts are still relatively dismal by coastal standards. Friday:  Freezing Level 200m. Precip: 7-12mm/10-20cm. Wind: Strong, SouthSaturday:  Freezing Level 400m.  Precip: Trace. Wind: West, Moderate gusting StrongSunday: Freezing Level surface. Precip: Trace Wind: Light, NE

Avalanche Summary

Numerous soft slabs to size 2.0 were reported from both treeline and alpine elevations Thursday.

Snowpack Summary

25 - 50cm of unconsolidated new snow is beginning to bond to a tenuous old surface which include: a crust at lower elevations and on solar aspects; old wind slabs in exposed areas, and fairly widespread large surface hoar. Moderate to locally extreme west/southwest winds have redistributed the new snow into soft and hard wind slabs in exposed terrain. This new snow is stubbornly reactive to human triggers primarily where cohesive wind slabs have formed, but reactivity is expected to become more widespread as the overlying slab develops with continued loading. Outflow winds are forecast for Friday which will likely result in some reverse loading in wind exposed terrain. The mid snowpack layers are generally well settled and strong. Facets at the base of the snowpack may resurface as a concern now that spring warming is on the doorstep and full-depth releases are becoming more likely (primarily in the northern part of the region).

Problems

Wind Slabs

An icon showing Wind Slabs
Light snow and strong winds have created new wind slabs in exposed terrain.  Watch for reverse loading on Friday as outflow winds pick up. Wind slabs will be most reactive where they overlie a weak layer of buried surface hoar and or crusts.
Choose conservative lines and watch for clues of instability.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Avoid freshly wind loaded features and watch for reverse loading with Fridays forecasted outflow winds.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 5

Valid until: Mar 15th, 2013 2:00PM