Avalanche Forecast
Issued: Feb 17th, 2018 4:19PM
The alpine rating is Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate - Due to the number of field observations
Weather Forecast
SUNDAY: Sunny. Ridge wind moderate to strong, northeast. Temperature -10. Freezing level valley bottom.MONDAY: Mostly sunny. Ridge wind light to moderate, northwest. Temperature -9. Freezing level valley bottom.TUESDAY: Mostly sunny. Ridge wind light, north. Temperature -6. Freezing level valley bottom.
Avalanche Summary
There have been no new reports of avalanches since Wednesday when a widespread natural avalanche cycle up to size 3.5 was reported following the intense loading of Tuesday's storm, with at least one avalanche running beyond it's historical runout distance. Explosive control work on Wednesday produced numerous storm slab releases up to size 2.5, at all elevations. At lower elevations, treeline and below, these slabs were failing on a layer of surface hoar buried by the storm snow on Tuesday.Large cornices have formed as a result of continued winds since Tuesday's storm event. These may weaken with the sun's influence during sunny, clear periods throughout the day.
Snowpack Summary
Approximately 40-60 cm of recent storm snow has fallen across the region since Tuesday with the highest snowfall amounts in the Terrace area.This new snow sits on a wide array of surfaces - including wind scour and old wind slabs at higher elevations on lee (downwind) slopes, as well as sun crusts on steep solar aspects and facets and surface hoar in sheltered locations at treeline and below. Also, a 5-20 cm thick crust/surface hoar layer that was buried early February and can be found 60-110 cm below the surface on all aspects up to 1400 m. In thinner snowpack areas (north and inland), a deeper crust / surface hoar layer that was buried in mid-January in sheltered areas at treeline and below could still be a concern for triggering from shallow spots.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 18th, 2018 2:00PM