New snow will bond poorly to the underlying crust. Small but reactive pockets of wind slab may form in isolated areas in the alpine and treeline.
New snow may be redistributed by northwest winds to create small but reactive pockets of wind slab in the alpine and treeline.
Older, hard wind slabs may exist in the alpine in the south of the region, where the new snow does not sit on a firm crust.
A passing frontal system will bring a more unsettled weather pattern with light snowfall expected throughout the week.
Sunday Overnight: Cloudy with snowfall. Light southerly winds at ridgetop. Freezing level around 500 m.
Monday: Cloudy with light snowfall. Light westerly winds at ridgetop. Freezing level around 1000 m.
Tuesday: Cloudy with light snowfall. Light to moderate northwest winds at ridgetop. Freezing level around 500 m.
Wednesday: Cloudy with light snowfall. Light to moderate northwest winds at ridgetop. Freezing level rising to 1300m in the afternoon.
During the rain event on Wednesday, a natural avalanche cycle occurred. Numerous wet loose avalanches were observed on all aspects and elevations. A few notable large slab avalanches were observed, which we suspect occurred during this rain event. these avalanches failed on deeper layers in the snowpack. These layers will not be a concern while a thick crust is present on the surface of the snowpack but may wake with a large amount of warming and load. Examples of these avalanches can be seen in this MIN report from the south of the region, and this report near Tumbler Ridge.
The last persistent avalanches associated with the late January surface hoar layer occurred on February 7th in the south of the region. These natural avalanches occurred on a shaded aspect below treeline.
A light amount of new snow is expected to bond poorly to a widespread surface crust. This 1-20 cm thick crust exists on all aspects and elevations, excluding areas in the high alpine in the south of the region that may remain crust-free. Where a thick surface crust is present, avalanches are unlikely.
Below the crust, last week's 30-50 cm of storm snow buried a weak layer formed in late January of facetted snow, a melt-freeze crust and surface hoar crystals. The last reported avalanche on this layer was on February 7th in the southeast of the region and it is becoming increasingly hard to find in the snowpack with no recent reactivity in tests.
The lower snowpack is generally strong and well-bonded. The base of the snowpack is expected to be weak and faceted in shallow, rocky slopes east of the divide.
