Archived

Avalanche Forecast

Feb 15th, 2017–Feb 16th, 2017

Alpine

4: High

The avalanche danger rating in the alpine will be high

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

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

1: Low

The avalanche danger rating below treeline will be low

Regions: Lizard-Flathead.

Forecast snowfall amounts are highly uncertain for Wednesday night and Thursday. Pay close attention to how much snow falls in your riding area, and be prepared to back-off to simple terrain.

Confidence

Low - Intensity of incoming weather systems is uncertain on Thursday

Weather Forecast

Wednesday night: 10-20cm of new snow / Extreme southwest winds / Freezing level at 1700mThursday: 15-20cm of new snow / Extreme southwest winds / Freezing level at 1700mFriday: Mix of sun and cloud / Moderate southwest winds / Freezing level at 1000mSaturday: Mix of sun and cloud / Light and variable winds / Freezing levels at 1000m

Avalanche Summary

No recent avalanches have been reported. Looking forward, I'd expect a widespread round of storm slab activity in response to new snow and extreme southwest winds on Wednesday night and Thursday. Rain at lower elevations will likely promote loose wet avalanche activity below treeline.

Snowpack Summary

By Thursday morning, up to 20cm of new snow is expected with continued snowfall anticipated throughout the day. Extreme southwest winds are forecast to shift these accumulations into reactive storm slabs in exposed high elevation terrain, while rain is expected at lower elevations. Beneath the new snow, you'll find a mix of hard old wind slabs, melt-freeze crusts and moist snow from the recent warm spell. Some weaknesses may still exist within the 90cm of storm snow from last week; however, recent warming has likely helped strengthen these layers. The mid and lower snowpack are generally well settled and stable but isolated basal weaknesses may exist in shallow snowpack areas.

Avalanche Problems

Storm Slabs

New snow and extreme winds are forecast to create reactive new storm slabs on Thursday. Conditions are expected to intensify throughout the day, so be prepared to back-off to simple terrain and watch your overhead exposure.

Be cautious as you transition into wind affected terrain.Use conservative route selection, choose moderate angled and supported terrain with low consequence.Good day to make conservative terrain choices.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Very Likely

Expected Size: 2 - 3

Loose Wet

Rain at lower elevations may promote loose wet avalanche activity. Use extra caution in steep terrain below treeline.

Be cautious of sluffing in steep terrain.Use extra caution on steep slopes if the snow is moist or wet.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 2