Avalanche Forecast
Issued: Feb 27th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
jleblanc,
Avalanche Canada
Stormy day ! Traveling in alpine terrain is NOT recommended. As avalanche hazard will increase throughout the day, choosing simple terrain is our best strategy.
Summary
Confidence
Weather Forecast
A series of storms are set to hit the region in the next few days. Moderate to heavy snowfalls, rising freezing levels, and warmers temperatures are expected until mid-week. The south part of the region, near Revelstoke, will receive the heaviest amounts of snowfalls.
Sunday night: Snow 5-10 cm overnight. Freezing level around 600 m. Alpine temperatures around -6 C. Moderate southwesterly winds gusting 50 km/h.
Monday: Snow 10-15 cm + 20-30 cm overnight. Freezing level rising to 1000 m. Alpine temperatures around -4 C. Moderate southwesterly winds gusting 50 km/h.
Tuesday: Snow 5-10 cm. Freezing level rising to 1600 m. Alpine temperatures around -2 C. Strong southerly winds gusting 65 km/h.
Wednesday: Flurries. Freezing level rising to 1400 m. Alpine temperatures around -4 C. Moderate southerly winds gusting 45 km/h.
Avalanche Summary
Saturday, recently formed wind slabs were showing signs of instability and propagation on specific features at treeline as skiers were able to produce large (size 2) slabs while skiing. Several natural wind slabs avalanches(up to size 2) were also reported in the Monashees.
In the neighbouring region of South Columbia, rider-triggered and natural persistent slabs activity (up to size 3) have been reported in the last few days.
With the current storm, avalanche activity will likely increase, and a natural cycle is expected late Monday / early Tuesday.
Snowpack Summary
15-25 cm of fresh snow has fallen Sunday throughout the region, with favoured amounts in the Monashees. This new snow is now burying a variety of surfaces including heavily wind-affected surfaces on most alpine slopes, fresh wind slabs on any open features, thin sun crust on steep south-facing slopes at all elevations, and widespread large feathery surface hoar crystal on sheltered areas. Below ~1200 m, 35-55 cm of snow is now overlying a thick melt-freeze crust.
Two weak layers exist within the upper snowpack: the mid-February layer (down 70 to 120 cm) and the mid-January layer (down 100 cm). They both consist of surface hoar / melt-freeze crust. Although reactivity of these layers had tapered off lately, they should be treated with extra caution with this incoming series of snowfalls as they may produce large, unexpected avalanches.
Terrain and Travel
- Travel in alpine terrain is not recommended.
- Watch for fresh storm slabs building throughout the day.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Good day to make conservative terrain choices.
Problems
Storm Slabs
Fresh storm slabs will build throughout the day. Their size and sensitivity will increase as the day progress. Use increased caution around treeline, where these slabs may overlay a weak layer, sun crust or hard wind slabs. Lee slopes, ridge crests and cross-loaded terrain are features of concern during a storm.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Two weak layers exist within the upper snowpack: the mid-February layer (down 70 to 120 cm) and the mid-January layer (down 100 cm). They both consist of surface hoar / melt-freeze crust. Evidence of their reactivity has been observed consistently all week. With increased load from the current storm and warmer temperatures, they have the potential to "wake up" and produce large, unexpected avalanches. In times of uncertainty, choose simple terrain, low consequence slopes and conservative lines.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 28th, 2022 4:00PM
