Avalanche Forecast
Issued: Mar 6th, 2017 4:33PM
The alpine rating is Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
Overnight: Flurries or light snow resulting in 3-5 cm of new snow combined with moderate southwest winds. Tuesday: Mostly sunny with moderate westerly winds and alpine temperatures around -15. Wednesday: overcast with light snow resulting in 3-5 cm of new snow combined with light southwest winds. Thursday: A mix of sun and cloud with increasing cloud and wind late in the day as the next system moves into the region.
Avalanche Summary
On Sunday, natural storm slab avalanches were reported up to size 3.0, and explosives control resulted in storm slab avalanches up to size 3.0.
Snowpack Summary
Just under a week of stormy weather has delivered a wide ranging 25-70 cm of new snow to the region, with the bulk of the new snow arriving over Friday night and blanketing localized pockets with up to 40 cm. The new snow has buried widely reported faceted surface snow as well as surface hoar reported at about 3mm on shaded aspects before the storm. Moderate to strong southerly winds accompanied the new snow, promoting the formation of touchy storm slabs at all elevations. Multiple reactive shears have recently been reported within this recent storm snow. Now roughly 40-90 cm below the surface you'll likely find the mid-February interface which is composed of a thick rain crust up to about 2000 m, sun crusts on steep solar aspects, and spotty surface hoar on shaded aspects. This layer has produced easy results in recent snowpack tests and has proven especially reactive on steep solar aspects. Several deeper weak layers also remain a concern, including the February 3rd surface hoar layer (50-130 cm deep), and the mid-January surface hoar layer in the northern Purcells (about 130 cm deep). Basal facets may still be reactive in shallow, rocky start zones.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 7th, 2017 2:00PM