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Avalanche Forecast

Feb 6th, 2016–Feb 7th, 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
2: Moderate
The avalanche danger rating below treeline will be moderate
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
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: Sea To Sky.

Rising freezing levels over the next few days will weaken the snowpack and increase the Avalanche Danger.

Confidence

Moderate - Timing or intensity of solar radiation is uncertain on Monday

Weather Forecast

On Sunday, expect up to 5mm of precipitation which should fall as rain at most elevations. On Monday and Tuesday the region will see increasingly clear skies as a dry ridge of high pressure develops. Freezing levels should rise from 500m to 2600m on Sunday, and then climb to 3600m for Monday and Tuesday. Ridgetop winds should remain moderate from the southwest on Sunday and Monday, and then become light on Tuesday.

Avalanche Summary

Explosives testing on Saturday produced storm slab avalanches to size 2.5 in alpine terrain. Although natural avalanche activity should taper off on Sunday, storm slabs may remain reactive to the weight of a rider. Looking further ahead, rising freezing levels and solar radiation on Monday should spark a round of loose wet avalanche activity on sun-exposed slopes. Warming will also increase the likelihood of triggering cornice falls, wet slabs and deep and destructive persistent slabs.

Snowpack Summary

On Friday between 60 and 100cm of new snow fell. Strong to extreme southwest winds shifted these accumulations into deep and dense storm slabs. Cornices were already large before the storm, and new growth is expected to be fragile. Where it still exists, the mid-January surface hoar layer may be found between 130 and 200 cm below the surface. The combination of ongoing heavy storm loading and warm temperatures has likely flushed out this weak layer in most areas. That said, warming and solar radiation forecast for the next few days may be what it takes to wake up this deep and destructive persistent weak layer.

Avalanche Problems

Storm Slabs

Recently formed storm slabs may remain reactive to the weight of a skier in higher elevation lee terrain. At lower elevations where temperatures are expected to rise above freezing, loose wet avalanches are also possible.
Be cautious as you transition into wind affected terrain.>Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Be cautious of wet sluffing in steep terrain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 4

Cornices

Cornices are huge and weak. They can be destructive by themselves, and may also become the trigger for a large slab avalanche on the slope below. Use extra caution around ridge crests.
Pay attention to overhead hazards like cornices.>Extra caution needed around cornices with current conditions.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 4