Archived

Avalanche Forecast

Feb 4th, 2015–Feb 5th, 2015

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

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

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: South Coast.

The exact timing of the storm is a little hard to pin down for Thursday. Danger ratings are based on the assumption that it's snowing/raining/windy for most of the day.

Confidence

Fair - Timing of incoming weather systems is uncertain on Thursday

Weather Forecast

The first of three distinct waves of well organized warm precipitation accompanied by strong SW winds should impact the South Coast Inland around lunch time Thursday. The rain/snow line should initially be around 1000m, steadily rising to 2300m by Thursday night as precipitation intensity increases. The second wave should arrive mid-day Friday with the freezing level hovering around 2300m. The final wave is expected to make its way inland Saturday evening. Storm totals in mm of water are expected to be in the 10 - 100 range.

Avalanche Summary

No new avalanche activity reported Tuesday. On Monday, skiers were triggering soft wind slabs in immediately leeward features up to size 2. On Sunday, small soft wind slabs were reported to be reactive to skier triggering. Sluffing from steep terrain features was also reported.

Snowpack Summary

10 - 30cm 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 up to 40cm thick 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

Storm Slabs

Avalanche activity is expected to be widespread at and above treeline Thursday afternoon. Screaming winds with a dynamic cool to very warm and wet storm suggests that avoidance is likely the best mitigation strategy once the storm arrives.

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Avoid exposure to overhead avalanche terrain, avalanches running on the thick crust may run further than you think.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely - Very Likely

Expected Size: 1 - 4