Avalanche Forecast
Issued: Jan 16th, 2013 9:00AM
The alpine rating is Wind Slabs, Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Track of incoming weather is uncertain
Weather Forecast
Synopsis: A strong frontal system pushing into the Northwest by Thursday. Precipitation amounts look heaviest close to the coast (Stewart, Bear Pass) but areas near Terrace should see at least moderate amounts. Overnight and Thursday: Moderate to heavy snow â 25-60 cm. The freezing level is around 800 m. Winds are very strong from the west-southwest. Friday: Cloudy with possible sunny breaks. The freezing level lowers to 500 m. Winds ease to moderate from the northwest. Saturday: Light snowfall. The freezing level is near valley bottom. Winds pick up again from the northwest.Â
Avalanche Summary
Recent reports include numerous natural moist slab avalanches up to Size 2.5 and widespread wet sluffing with warm temperatures and light rain on Monday. In the eastern part of the region, extreme winds caused numerous thin wind slab avalanches in alpine areas below ridgetops, and strong solar radiation caused a few Size 2 released right to the ground. On Sunday there was a report of a size 1.5 skier triggered avalanche on a steep unsupported convex roll on a northerly aspect. This event likely released on the late December surface hoar layer approximately 60 cm deep. There are also a few reports of glide releases in steep south facing terrain.
Snowpack Summary
Mild temperatures have resulted in moist snow below treeline, while strong or extreme upper winds have scoured areas and produced hard or soft wind slabs in a variety of areas at all elevations. Below this, weaknesses within the 30-60cm of well settled storm snow are only producing resistant fractures in recent snowpack tests. However, a persistent weakness of surface hoar or facetted snow buried at the end of December sits at the base of this recent storm snow and continues to react as sudden fractures in snowpack tests particularly below treeline. The mid and lower snowpack is generally well settled and strong, although well developed basal facets remain a concern in shallow snowpack areas.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Storm Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 17th, 2013 2:00PM