Avalanche Forecast
Regions: Kootenay Boundary.
Forecast rain to mountain-tops will rapidly destabilize the upper snowpack and initiate a loose wet avalanche cycle.
Confidence
Moderate - Freezing levels are uncertain
Weather Forecast
THURSDAY NIGHT: Rain to near 2500 m; 5-10 mm / Strong, southwesterly winds / Alpine low 6 C / Freezing level 2700 m.
FRIDAY: Rain to near 2300 m; 5-10 mm / Strong, southwesterly winds / Alpine high 6 C / Freezing level 2500 m.
SATURDAY: Sunny / Light, northwesterly winds / Alpine high 5 C / Freezing level 2200 m.
SUNDAY: Sunny / Light, northwesterly winds / Alpine high 8 C / Freezing level 2500 m.
Avalanche Summary
No new avalanches were reported in this region on Wednesday. However, avalanche activity is expected to increase on Friday with the forecast rain to mountain-tops.
On Tuesday, a party skiing near Kootenay Pass reported "whumphing" on solar aspects near ridgetops and triggered a size 2 storm slab avalanche sitting on a crust on a north aspect at around 2000 m. See the MIN report HERE.
On Sunday, a skier triggered a small size 1 wind slab that then stepped-down and triggered a size 2.5 persistent slab avalanche on a northwest aspect in the alpine. See the MIN report HERE.
Snowpack Summary
Rain to mountain-tops Thursday night will rapidly warm the snow and initiate a loose wet avalanche cycle at treeline and above. 20-40 cm recent snow sitting on a crust on all aspects below 2000 m which has recently been reactive to riders.
Below treeline snow is disappearing rapidly.
Avalanche Problems
Loose Wet
Forecast rain to mountain-tops will rapidly destabilize the upper snowpack and initiate a loose wet avalanche cycle.
- Minimize overhead exposure during periods of heavy loading from rain/snow and wind.
- Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.
- A moist/wet snow surface, pinwheeling and natural avalanches all indicate a weakening snowpack.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely - Very Likely
Expected Size: 1 - 2
Storm Slabs
Forecast rain to mountain-tops will rapidly destabilize the upper snowpack and may trigger recently formed storm slabs sitting slippery crusts.
- Minimize overhead exposure during periods of heavy loading from rain/snow and wind.
- Pay attention to changing conditions with elevation/aspect.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Likely
Expected Size: 1 - 2