Human-triggered avalanches remain likely.
The persistent slab problem remains a serious concern for all back country travellers.
Avoiding avalanche terrain is recommended.
South and west winds over the last few days have led to the development of wind effect and small thin slabs at treeline and above.If initiated, these slabs may be enough to activate deeper layers.
Light snow and increased winds through Monday will contribute to these slabs.
A 40–90 cm slab sits atop mid-pack facets and depth hoar at the ground. Many avalanches have failed on both layers with wide propagations (persistent and deep persistent slabs). The potential for remote triggering remains. These problems are slow to heal and will remain with us for some time.
Over the past two weeks, many avalanches up to size 3.5 have occurred, including human-triggered, remote-triggered, and natural slides. These are all on persistent layers often stepping down to the ground.
On March 18th, a group digging a snowpit in low-angle terrain on Observation Peak felt a whump, triggering 5-6 remote avalanches up to size 2.5.
Skiers had a near miss with a significant slab near SSV Saturday.
Expect surface crusts on solar aspects treeline and below.
Since March 8... 40-90 cm of snow has accumulated and settled into a slab, with the deepest amounts found in the Bow Summit area and along the Wapta. This sits on a very weak, faceted mid and lower snowpack and fails easily in snowpack tests. This condition will be slow to stabilize.
Friday's Bow Summit fracture line profile is attached below.
Trace amounts of snow will accumulate overnight Saturday as west winds increase to moderate in the alpine. Treeline temperatures drop to near -10C.
Sunday, flurries continue as winds increase to the strong range and the freezing level approaches 1900m.
Watch for rising freezing levels into the week.
