Wind slabs may remain sensitive to human triggering in the alpine and there is potential for large avalanches at and below treeline due to the presence of a persistent slab problem. Check out our forecater's blog that goes into more detail
here.
Summary
Confidence
Moderate - Wind effect is extremely variable
Weather Forecast
Cold, dry, arctic air continues to dominate the weather pattern for the foreseeable future.SATURDAY NIGHT: Freezing level at valley bottom, around -20 C in the alpine, light variable winds at most elevations with moderate northeast wind at ridgetop that should diminish through the night, no significant snowfall expected.SUNDAY: Mostly clear skies, freezing level at valley bottom, around -20 C in the alpine, light variable wind at all elevations, no significant snowfall expectedMONDAY: Clear skies at dawn with cloud cover increasing throughout the day, freezing level at valley bottom, around -20 C in the alpine, light southerly wind at all elevations, no significant snowfall expected. A trace of snow possible Monday night.TUESDAY: Scattered cloud cover, freezing level at valley bottom, around -20 C in the alpine, light variable wind at all elevations, a trace of snow possible.
Avalanche Summary
On Friday avalanches failed on the mid-January surface hoar to size 1 on north and northeast facing slopes between 1700 and 2000 m. The persistent weak layer that was buried in mid January continues to be reactive to human triggers. Human triggered avalanches up to size 2.5 have been reported almost everyday in the last week. This layer is sensitive enough for avalanches to be triggered remotely (from a distance). This layer has been the most reactive at treeline and below, although there have been a few reports of its presence in isolated sheltered areas in the alpine.
Click here to see a Mountain Information Network post that described conditions in Allen Creek on Wednesday.Strong to extreme north, northeast and east wind over the last 72 hours has created wind slabs that may remain sensitive to human triggering in wind exposed features. Checkout this
great MIN here from Friday.
Snowpack Summary
30-60 cm of old storm snow is sitting on surface hoar (feathery crystals), facets (sugary snow) and a crust on sun-exposed slopes. In many areas, recent strong winds have redistributed the new snow and formed wind slabs on all aspects due to shifting wind directions.The most notable feature in the snowpack is a persistent weak layer that was buried in mid January, which is now 50-80 cm below the surface. This layer consists of surface hoar and a crust on sun-exposed slopes. It is most prominent at treeline and below, and continues to produce avalanches.
ghelgeson,
Avalanche Canada
