Avalanche Forecast
Issued: Dec 25th, 2018 3:57PM
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
The BC weather will take a holiday break over the next couple of days as the wild storm cycle of recent weeks eases in the Pacific.CHRISTMAS NIGHT: Freezing level at valley bottom, light variable wind, no significant precipitation expected. BOXING DAY: Broken cloud cover, freezing level at valley bottom, light southwest wind, trace of snow possible. THURSDAY: Broken cloud cover, freezing level at valley bottom, light northerly wind, no significant precipitation expected. FRIDAY: Scattered cloud cover, freezing level at valley bottom, light west/southwest wind with potential for moderate westerly gusts in the afternoon at upper elevation, trace of snow possible.
Avalanche Summary
Avalanche Control work on Monday produced avalanches from size 1 to 3 on north through northwest facing terrain between 1900 and 2700 m. One of the more interesting results was a size 1.5 wind slab that was remote triggered from 200 m away on a north facing slope around 2100 m. No new natural avalanche activity to report.On Sunday natural avalanche activity began to taper off, but large persistent slabs continued to be reactive to human and explosive triggers. On Sunday, a large (size 2.5) persistent slab avalanche was triggered by a snowmobiler in Silent Pass. The avalanche occurred on a wind loaded northwest-facing slope in the alpine. See details in the MIN report. Over the weekend explosives produced numerous large persistent slab avalanches (size 2-4) in alpine terrain. The avalanches occurred on all aspects and failed on several different weak layers including the early December weak layer and weak facets at the bottom of the snowpack. Over the past two weeks, several large persistent slab avalanches were remotely triggered from skiers on adjacent slopes, particularly in the Golden area.
Snowpack Summary
5-15 cm of low density snow sits above wind slabs in the alpine, and in some isolated areas above small surface hoar (feathery crystals).A weak layer that formed during the dry spell in early December is now 50-100 cm deep. The layer is composed of facets (sugary snow), surface hoar (feathery crystals), and a sun crust (on south aspects). Another similar weak layer is buried 80-150 cm. Finally, the base of the snowpack has weak faceted layers at alpine and treeline elevations. All of these weak layers have been producing large avalanches over the past week. Human triggering any of these layer is most likely on slopes that didn't previously avalanche and on slopes that have variable snowpack depth (such as rocky alpine features).
Problems
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 26th, 2018 2:00PM