Avalanche Forecast
Issued: Mar 9th, 2017 5:42PM
The alpine rating is Persistent Slabs and Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
High -
Weather Forecast
Friday: Mainly clear skies / Moderate easterly winds / Alpine temperature of -15Saturday: Overcast skies with light flurries / Moderate easterly winds / Alpine temperature of -12Sunday: 15-30cm of new snow / Moderate southerly winds / Alpine temperature of -5
Avalanche Summary
On Monday two avalanches were simultaneously remotey-triggered below treeline west of Terrace. See here for the excellent details in the Facebook post. We had reports of two rider-triggered wind slab avalanches (Size 1.5 and 2.0) southwest of Terrace on Sunday. In both cases the crown height was 50cm and shooting cracks were also reported in mellow terrain. There was a remote-triggered Size 1 in the Shames backcountry, also with a 50cm crown, running on a weak facet layer. These avalanches speak to the touchy persistent avalanche problem in the region.Strong winds on Thursday should promote a new round of wind slab activity. The persistent slab problem is expected to remain touchy as the recent storm snow settles into a cohesive slab over top of the late February persistent weak layer.
Snowpack Summary
On Tuesday night the region received between 5-40cm of new snow with the greatest accumulations occurring in the south of the region. Southwest winds and more recent easterly winds are expected to have redistributed this new snow forming fresh wind slabs on a variety of aspects. 70-150 cm below the surface you'll find a variety of old surfaces which were buried in late February. These weak surfaces, which remain the primary concern in the region, include surface hoar, facets, stiff wind slabs and a melt-freeze crust below 1600 m. The overlying slab remains reactive on this interface, with ongoing reports of whumpfing in flat terrain. Moreover, we've had reports of sudden, propagation-likely test results on this layer. Below this interface the snowpack is generally settled and strong, with the exception being shallow snowpack areas around Bear Pass and Ningunsaw where basal facets remain an ongoing concern.
Problems
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 10th, 2017 2:00PM