Avalanche Forecast
Issued: Jan 30th, 2016 3:00PM
The alpine rating is Storm Slabs, Cornices 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
Tonight and Sunday: Periods of snow. 5-10 cm tonight and 15-20 cm on Sunday. The freezing level is around 600-800 m. Winds are moderate from the S-SW easing to light. Monday: Cloudy with flurries and clearing. The freezing level is around 500-700 m and winds are light from the SW. Tuesday: Mainly sunny. The freezing level remains near 500 m and winds are light and variable.
Avalanche Summary
A few natural size 2-3.5 persistent slab avalanches were reported near Whistler on Friday. Some may have started as loose wet slides that stepped down and triggered deep slabs. All of these slides were from slopes near treeline (1800-2000 m). These likely occurred during the height of the storm on Thursday night. Explosives control also produced numerous size 2 storm slabs. Cooler and drier conditions should help improve stability and make triggering much less likely.
Snowpack Summary
By Sunday morning there could as much as 40 cm of dry new snow with the snow line extending down to at least 800 m. Expect fresh wind slabs in exposed lee terrain and the potential for storm slabs or loose dry avalanches. The intense storm earlier this week dropped around 80mm of precipitation throughout the region with fluctuating freezing levels. In the alpine deep and dense storm slabs formed and there was substantial cornice growth. At and below treeline the new snow likely sits on a crust or moist/wet snow. Where it still exists, the mid-January surface hoar layer is between 100 and 180 cm below the surface. The combination of heavy storm loading and warm temperatures has likely flushed out this weak layer in most areas. There is still some uncertainty regarding the sensitivity and distribution of this persistent avalanche problem, especially at high elevations in the north of the region where it remains reactive in snowpack tests.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Jan 31st, 2016 2:00PM