Archived

Avalanche Forecast

Jan 16th, 2019–Jan 17th, 2019

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Kootenay Boundary.

Avalanche hazard will slowly increase and extend to lower elevations with incremental snowfall. For now, steep, rocky terrain and areas with thin or variable snowpack are most suspect for lingering problems.

Confidence

Low - Intensity of incoming weather systems is uncertain on Thursday

Weather Forecast

WEDNESDAY NIGHT: Cloudy with clear periods. Freezing level valley bottom. Alpine high -2. Moderate south-southeast winds. THURSDAY: Cloudy with flurries, 5-10 cm. Freezing level below 1000 m. Alpine high -3. Moderate south-southeast winds.FRIDAY: Cloudy with isolated flurries, 5-10 cm. Freezing level 1200 m. Alpine high -3. Moderate southwest winds.SATURDAY: Flurries, up to 10 cm. Freezing level 1200 m. Alpine high -2. Moderate southwest winds.More details can be found in the Mountain Weather Forecast.

Avalanche Summary

While clearing a road on Tuesday, a vehicle triggered a size 1.5-2 avalanche on a cutbank below treeline. Otherwise no recent avalanches have been reported.There were several size 1-1.5 loose wet avalanches on sunny slopes on Saturday and into Sunday.A wind-loaded NW slope was triggered remotely by skiers on Copper Mountain on Friday. The avalanche was reported to have failed on a layer of surface hoar. See the MIN report here.

Snowpack Summary

A temperature crust can be found on all solar aspects and most places tree line and below. Cold, dry snow may still be found on north aspects in the alpine. Large surface hoar has begun to form, and is most noticeable on shaded aspects and below tree line. While not a concern yet (and maybe really neat to ski), this potentially weak layer well not bond will with incoming snow.Wind slabs exist in alpine areas and may overlie buried surface hoar. Professionals continue to monitor a couple of persistent weak layers in the upper 50-150 cm of the snowpack. Persistent weak layers are most likely to be triggered from thin, rocky areas with a variable snowpack or with a large load, like cornice fall.

Avalanche Problems

Wind Slabs

Wind slabs may be found near ridges and ribs. In some areas, these may overlie a touchy buried surface hoar layer. As new snow accumulates, the deepest and more reactive deposits will be in wind-loaded terrain features.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1 - 1.5