Avalanche Forecast
Issued: Mar 6th, 2012 8:47AM
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 - Timing, track, or intensity of incoming weather is uncertain on Friday
Weather Forecast
Wednesday: Mostly clear with light winds and freezing levels rising to around 1200m. Thursday: Increasing high clouds throughout the day with light winds and freezing levels as high as 2500m for the southernmost part of the region. Friday: Mostly cloudy with snow increasing in the afternoon. Freezing levels around 1000m and moderate southwesterly winds.
Avalanche Summary
In the northern part of the region, recent slab avalanches reached Size 2.5 on southern aspects and Size 1.5 on all other aspects. They were mostly natural soft wind slabs on northerly aspects, but some were human triggered and suspected to have involved deeper persistent weaknesses from mid-February. In the Coquihalla Pass area recent heavy loading from snow and wind resulted in several Size 3-4 natural avalanches. Two Size 4 slab avalanches were observed on northwest through east aspects. One was a 5-10m thick slab and took out large swaths of mature forest in the runout, while the other was a relatively thin slab at 1-2m but propagated approximately 1.5 Km across a bowl.
Snowpack Summary
In the northern part of the region south aspects are described as spooky with a very hollow feeling, but all other aspects seem to be well settled with only surface instabilities. Up to 45cm of recent storm snow is sitting on a poorly bonded crust on sun-exposed slopes with easy sudden collapses below the crust, and the mid-February buried surface hoar and/or facet persistent weakness remains a concern and is particularly touchy where there is an associated crust at treeline and below and on south aspects. Meanwhile in the Cascades, 70-100cm of recent storm snow combined with five straight days of sustained extreme winds has created a highly unstable wind and storm slab problem that will probably take a few days to settle and strengthen.
Problems
Wind Slabs
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Aspects: North, North East, East, South East, South.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 7th, 2012 8:00AM