Archived

Avalanche Forecast

Dec 25th, 2015–Dec 26th, 2015

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

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

2: Moderate

The avalanche danger rating below treeline will be moderate

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

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Northwest Inland.

Strong winds and moderate to heavy snow fall are expected to drive a natural avalanche cycle on Saturday.

Confidence

Moderate

Weather Forecast

Snow is expected to start falling early Saturday morning becoming heavy in the afternoon. Up to 15cm is expected through the day and overnight with another 5 forecast for Sunday morning. Monday looks to be mainly dry. An Arctic front just inland will keep things cool with freezing levels at valley bottom. Strong southwest winds are expected to build on Saturday becoming moderate to light westerlies on Sunday and northeasterly by Monday as a ridge moves inland.

Avalanche Summary

No recent avalanche have been reported.

Snowpack Summary

I suspect that the recent cold temperatures have faceted out the upper snowpack. As of Friday ski pen at treeline was reported to be about 20-30 cm and. This means there is lots of low density surface snow available to blow around when the winds pick up. We're still dealing with a thin, early-season snow pack for much of the Northwest Inland region. Between 80 and 100 cm of snow can be found at tree-line in the south and west of the region, with closer to 60 cm in the east. A weak basal layer probably exists in most areas.

Avalanche Problems

Storm Slabs

Storm slabs will build rapidly, especially in wind loaded features at tree line and in the alpine. The new load will test the strength of the thin, weak snowpack.

The new snow will require several days to settle and stabilize.>Avoid thin, rocky or sparsely-treed slopes.>Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 3