Avalanche Forecast

A passing frontal system will bring light snowfall, with greater amounts forecast for Thursday.

Monday Overnight: Mainly cloudy, light snowfall. Freezing level dropping to valley bottom. Light to moderate northwesterly winds. 

Tuesday: Partially cloudy with light flurries. Freezing level rising to 500 m. Moderate to strong northwesterly winds. 

Wednesday: Mainly cloudy and snowing. Freezing level rising to 1000 m in the afternoon. Moderate to strong northwesterly winds. 

Thursday: Snowing, heavy at times. Freezing level rising to 1500m. Strong to extreme westerly winds. 

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 slab 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 from the past few days 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. In open areas in the alpine and treeline, northwesterly winds may redistribute the new snow into small but reactive pockets of wind slab in lee areas.

Below the crust, last week's 30-50 cm of storm snow buried a weak layer formed in late January. This layer consists of facetted snow, a melt-freeze crust and surface hoar crystals in sheltered areas. This layer of buried surface hoar is becoming increasingly hard to find in the snowpack. Our field team was able to find this layer in the Pine Pass area in sheltered areas between 1250-1500 m, their full report can be seen here. Currently, this layer is bridged by a thick surface crust in most areas but will be on our radar with a significant amount of warming and new load. 

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.

• A crust on the surface will help bind the snow together, but may make for tough travel conditions.
• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Wind slabs may be poorly bonded to the underlying crust.
• Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.