Register
Get forecast notifications
Create an account to receive email notifications when forecasts are published.
Login
Archived

Avalanche Forecast

Jan 18th, 2016–Jan 19th, 2016
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable
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.

Reports of whumpfing indicate a weak layer buried at the beginning of January may still be sensitive to light loads. Choose conservative terrain and watch for clues of instability.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Expect a mix of sun and cloud with isolated flurries on Tuesday and Wednesday. Ridgetop winds should be light to moderate from the southwest on Tuesday switching to light and northwesterly on Wednesday. A Pacific system will move into the region on Thursday bringing steady snowfall and strong southwest winds. Freezing levels should sit at or near valley bottom for the forecast period.

Avalanche Summary

Over the weekend we had limited observations of new avalanches. With the forecast static weather pattern I expect a drop in natural avalanche activity; however, human triggered persistent slab avalanches remain a concern in many areas.

Snowpack Summary

10-15 cm of new snow and moderate southerly winds have likely created fresh wind slabs in high elevation lee terrain. 35-60 cm below the surface you'll find a weak layer of well-developed surface hoar and a hard crust on steep solar aspects. Ongoing Mountain Information Network reports of whumpfing and shooting cracks show this layer is still sensitive to light loads. I would anticipate increased reactivity at this interface in areas where the overlying slab is deep and has gained cohesion through wind pressing, warming, and/or settlement. The mid and lower snowpack are generally well settled and strong.

Avalanche Problems

Persistent Slabs

Recent storm accumulations overlie a weak layer of surface hoar. Touchy conditions are expected in areas where the recent storm snow has settled into a cohesive slab.
Dig down to find and test weak layers before committing to a line.>Be aware of the potential for large avalanches due to the presence of buried surface hoar.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 4

Wind Slabs

Recently formed wind slabs are likely gaining strength, but may still be sensitive to light loads in unsupported lee terrain.
Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Be alert to conditions that change with elevation.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 3