Archived

Avalanche Forecast

Dec 19th, 2017–Dec 20th, 2017

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

4: High

The avalanche danger rating below treeline will be high

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: South Rockies.

A significant storm is expected to impact this region on Tuesday night and into Wednesday, resulting in high avalanche danger.

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Wednesday

Weather Forecast

Tonight: 15-25 cm new snow expected, particularly on the eastern side of the range. Moderate easterly winds.Wednesday: a further 15-25 cm new snow expected, again favouring the eastern sides. Moderate northeasterly winds. Treeline temperatures around -9C.Thursday: Mostly dry during the day. Moderate northwesterly winds. Treeline temperatures around -10C.Friday: Light snow, 4-6 cm. Light easterly winds. Treeline temperatures around -12C.

Avalanche Summary

Avalanches are likely to occur on Wednesday in response to forecast heavy snow and strong winds.

Snowpack Summary

Up to 30 cm of recent snow has fallen in conjunction with variable winds. This new snow has fallen on a variety of surfaces including old crusts, wind-scoured surfaces and, in sheltered terrain at and below treeline, very large feathery surface hoar crystals. The two crusts that were buried near the end of November can be found lower in the snowpack. A third crust from the end of October exists near the base of the snowpack. Recent testing on this crust did not produce significant results.

Avalanche Problems

Storm Slabs

Touchy storm slabs will develop as new snow continues to accumulate. Avalanches have the potential to run further than expected.

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Very Likely

Expected Size: 1 - 3