Avalanche Forecast
Issued: Mar 8th, 2017 4:20PM
The alpine rating is Persistent Slabs and Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate -
Weather Forecast
Expect a mix of sun and cloud for the forecast period. Ridgetop winds should remain generally light to moderate from the east with alpine temperatures sitting at about -15.
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. These avalanches speak to the touchy persistent avalanche problem in the region.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.Conditions will 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 are expected to have redistributed this new snow forming fresh wind slabs in exposed lee terrain. 70-120 cm below the surface you'll find a variety of old surfaces which were buried in late February. These surfaces include surface hoar, facets, crusts, stiff wind slabs and a melt-freeze crust below 1600 m. The overlying slab remains very reactive on this interface which was buried in late February, resulting in widespread whumpfing and cracking in flat terrain. Moreover, we've had reports of sudden, propagation-likely test results on weak facets or the late-February crust / surface hoar.Below this interface the snowpack is generally settled and strong with the exception in 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: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 9th, 2017 2:00PM