Avalanche Forecast
Issued: Mar 19th, 2012 10:06AM
The alpine rating is Wind Slabs, Storm Slabs and Deep 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 Tuesday
Weather Forecast
Another Pacific frontal system begins to track inland from the Coast late tonight into Tuesday. This will bring more snow, wind and rising freezing levels. Tuesday: Snow amounts near 5 cm overnight, another 10-15 cm during the day. Ridgetop winds strong from the West. Treeline temperatures near -2. Freezing levels 1100-1300 m. Wednesday: Convective weather pattern, cloudy with flurries. Ridgetop winds through the day up to moderate from the West. Treeline temperatures near -5. Freezing levels valley bottom. Thursday: Moderate to heavy snow amounts expected. Ridgetop winds strong from the SW. Freezing levels may spike up to 1300 m.
Avalanche Summary
No new reports on Monday. On Sunday, a size 1.5 avalanche released naturally on a north aspect. On Saturday, a recent avalanche was observed on a north aspect in the southern Elk Valley, suspected to have started as a wind slab and ending in moist snow. Evidence of a previous natural cycle was also reported. On Friday, explosives produced size 1-2 avalanches.
Snowpack Summary
Unsettled weather has brought snow and wind through most of the week, creating variable wind slabs and storm slabs. On Saturday, snowpack tests in the Elk Valley, east of Sparwood, showed a couple of shears in the top 20cm of storm snow. A rain crust is buried about 1m down. Two surface hoar layers, buried in February and now 1-2m deep, exhibited sudden planar results, which have been repeated in a number of locations. This means they still have the potential to produce widely-propagating, destructive avalanches if triggered. Most likely triggering mechanisms are a person traveling on a thin snowpack area, or a storm slab, wind slab or cornice stepping down. Basal facets may still exist, particularly in shallow snowpack areas with steep, rocky start zones. Cornices have grown large and threaten slopes below.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 20th, 2012 9:00AM