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Avalanche Forecast

Feb 3rd, 2015–Feb 4th, 2015
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
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
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
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
3: Considerable
The avalanche danger rating below treeline will be considerable

Regions: Sea To Sky.

Lingering wind slabs may still be a concern on Wednesday. Expect rapidly decreasing conditions on Thursday with the arrival of the storm system.

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain on Thursday

Weather Forecast

A ridge of high pressure should keep the South Coast mainly dry on Wednesday.  Mostly cloudy conditions are expected with sunny breaks possible.  Freezing levels are forecast to be around 1200m and alpine winds should remain light from the SW.  The warm front is expected to arrive Wednesday night or early Thursday morning.  There is some uncertainty regarding precipitation amounts but the region should see 20-40mm of precipitation by Thursday evening.  Freezing levels are forecast to rise to around 2000m by the end of the Thursday and alpine winds will become strong from the SW.  Friday should see similar storm conditions with heavy precipitation, freezing levels over 2000m, and strong alpine winds.

Avalanche Summary

On both Sunday and Monday, ski-cutting and explosives were producing thin soft slabs which were running on the firm crust layer. These were limited to size 1 and were isolated to wind affected terrain. Sluffing from steep terrain features was also reported. Similar conditions are expected on Wednesday with natural avalanches not expected and skier-triggered avalanches remaining possible in wind-loaded features.

Snowpack Summary

Around 20cm of new snow overlies a hard rain crust that exists up to at least 2100m. In exposed terrain, the new accumulations have been shifted by strong SW winds into wind slabs which may be especially reactive due to the underlying crust. Deeper snowpack weaknesses have become unreactive on account of the strong capping crust layer.

Avalanche Problems

Wind Slabs

Recent snowfall and strong southwest winds have formed wind slabs in exposed leeward terrain features.
Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2