Avalanche Forecast
Issued: Feb 22nd, 2015 7:54AM
The alpine rating is Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Timing or intensity of solar radiation is uncertain on Monday
Weather Forecast
The dry ridge will persist throughout the forecast period bringing a mix of sun and cloud until Wednesday. Winds will generally remain light from the northwest, although strong gusts are likely on Tuesday. On Monday we can expect an inversion with above-freezing alpine temperatures. Freezing levels will hover around 1500m on Tuesday, and then drop to about 800m on Wednesday.
Avalanche Summary
Last week there were reports of natural and explosive triggered cornice falls and slabs, typically size 2-3 and all from alpine terrain. Avalanche activity of this nature has gradually tapered off throughout the week. Looking forward, thin wind slabs may still be sensitive to triggering in high elevation terrain. Warming forecast for Monday may spark some loose wet avalanche activity on sun-exposed slopes while increasing the likelihood of deeper persistent slab avalanches.
Snowpack Summary
Generally light amounts of new snow cover the previous variable snow surface of crusts, surface hoar, dry facetted snow, or wind affected snow depending on aspect and elevation. Thin new wind slabs are likely in exposed lee terrain, and cornices remain large and weak. The 'Valentine's Day' crust is thick and supportive below 2100 m. The late-Jan crust/surface hoar layer is 1-2 m deep in the west, and can be found within the upper metre of the snowpack further east. It is variably reactive in snowpack tests and still the main concern in many areas. The mid-January surface hoar, deeper again, is also a concern in some areas. The mid-December and mid-November weak layers of crusts and facets can still be found near the bottom of the snowpack, particularly in shallower eastern parts of the Purcells.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Feb 23rd, 2015 2:00PM