Avalanche Forecast

Issued: Apr 20th, 2017 4:26PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Loose Wet, Cornices and Wind Slabs.

cgarritty, Avalanche Canada

South Coast.

Warm temperatures and sunshine will combine to promote reactivity in a range of avalanche problems on Friday.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Friday: A mix of sun and cloud. Light to moderate southeast winds. Freezing level to 2200 metres with alpine temperatures around 0 to +1.Saturday: Cloudy with periods of rain and wet snow bringing up to 5 cm of new snow to alpine elevations before intensifying in the evening. Moderate to strong southeast winds. Freezing level dropping to 1700 metres over the day with alpine temperatures around 0 to -2.Sunday: Cloudy with flurries bringing around 5 cm of new snow to higher elevations over the day. Light south winds. Freezing level to 1500 metres with alpine temperatures of -4.

Avalanche Summary

No new avalanches have been reported, but there have been limited observations lately.Please enter your observations on the Mountain Information Network (MIN). See here for details.

Snowpack Summary

Stormy weather over the beginning of this week has brought about 50mm of precipitation to the North Shore Mountains, most of which fell as rain to the summits. In the Sky Pilot area, 30-40cm of snow likely fell above 1600m and was redistributed into wind slabs in lee terrain by recent southeast winds. Cornices also gained fragile new growth over the same time period. Below the wind effect, the new snow is now likely to be forming a good bond to the underlying crust. The mid and lower snowpack are well settled and strong, however southerly aspects at treeline and below contain moist snow that typically has not been refreezing overnight.

Problems

Loose Wet

Warm temperatures and strong sunshine will promote loose wet avalanches throughout the day on Friday, especially in steep terrain. Loose wet slides may occur naturally or with a human trigger.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Minimize exposure when solar radiation is strong, especially if snow is moist or wet.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Cornices

Where cornices exist, they are unstable and should be avoided. Daytime warming and strong solar radiation will make cornices especially weak on Friday.

Avoid traveling on slopes that are exposed to cornices overhead.Stay well to the windward side of corniced ridges.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Wind Slabs

Recent southeast winds are likely to have redistributed our new snow into windslabs on leeward aspects in the alpine. Strong solar effect will promote the reactivity of these wind slabs on Friday.

Be increasingly cautious as you transition into wind affected terrain.Be especially careful with wind loaded pockets near ridge crests and roll-overs.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Apr 21st, 2017 2:00PM