Light to moderate amounts of snow accompanied by wind over the next few days will gradually raise danger ratings into the weekend.
Summary
Confidence
Moderate - Forecast snowfall amounts are uncertain on Friday
Weather Forecast
THURSDAY: Flurries, accumulation 5cm / Moderate south wind / Alpine temperature -5 / Freezing level 1300mFRIDAY: Snow, accumulation 15-20cm / Moderate to strong southwest wind / Alpine temperature -4 / Freezing level 1300mSATURDAY: Flurries, accumulation 5cm / Moderate to strong southwest wind / Alpine temperature -6 / Freezing level 1000m
Avalanche Summary
Recent reports indicate both natural and human triggered wind slab avalanches in alpine and tree line lee terrain to size 1.5. On Thursday, wind slabs may remain reactive to human triggers and at upper elevations the deeper mid-February weak layer continues to present a low likelihood of triggering yet would produce a large avalanche and thus a high consequence if triggered.
Snowpack Summary
On Tuesday the freezing level reached 2000+m. This turned the last weekend's storm snow moist and subsequently froze in the overnight period. 10-15cm of new snow at upper elevations now sits above. A rain crust which formed last week is now buried 30-50cm. Thicker wind slabs and large cornices likely exist in alpine terrain. The mid-February crust/facet layer may still be found at the upper end of tree-line into the alpine and is 80-120 cm deep and may be up to 200 cm deep in wind loaded terrain. This layer was reactive prior to recent warming events, but now there's some uncertainty as to how long it will remain reactive.
mbender,
Avalanche Canada
