Avalanche Forecast

Issued: Mar 4th, 2016 7:39AM

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

jlammers, Avalanche Canada

Sea To Sky.

Friday's storm totals are expected to vary greatly across the region. Pay close attention to how much snow falls in your riding area as snowfall amounts and warming will drive the Avalanche Danger on Saturday.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain on Friday

Weather Forecast

The region may see up to 30cm of new snow on Friday night with extreme southwest winds. On Saturday morning expect overcast skies and lingering flurries with the possibility of sunny breaks in the afternoon. Another system will bring in up to 20cm of new snow and strong southerly winds between Saturday night and Sunday. On Monday a clearing trend is expected. The freezing level should hover around 1500m for most of the forecast period although there may be a brief spike to about 2000m on Saturday afternoon.

Avalanche Summary

Natural and artificially triggered storm slab avalanche activity in the size 2-3 range was reported from across the region on Wednesday. More recently, observations have been limited due to inclement weather. While recent storm accumulations will likely gain strength over the next few days, further storm loading on Friday night will spark a new round of destructive wind and storm slab avalanche activity on Saturday.

Snowpack Summary

Continued heavy snowfall and extreme southerly winds have formed deep and reactive storm slabs on lee and cross-loaded alpine and treeline features. On windward terrain, extensive scouring has been reported. Ongoing stormy weather has also encouraged extensive cornice growth. Recent storm totals (which vary from about 60cm to over 100cm) overlie a temperature crust, old wind slabs and spotty surface hoar. The mid and lower snowpack are generally strong and well-settled.

Problems

Storm Slabs

Deep and destructive storm slabs are forecast to develop on Friday night. Don't let sunny breaks lure you into aggressive terrain as you may get surprised with nasty consequences.

Be cautious as you transition into wind affected terrain.>Be aware of the potential for wide propagations due to the presence of hard windslabs.>Stay off recent wind loaded areas until the slope has had a chance to stabilize.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Cornices

Cornices are reported to be very large and weak. Stay well back from ridgecrests and watch your overhead hazard especially with warming forecast for Saturday afternoon.

Do not travel on slopes that are exposed to cornices overhead.>Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Loose Wet

Warming and solar radiation on Saturday afternoon will likely trigger loose wet avalanches in steep, sun-exposed terrain.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Mar 5th, 2016 2:00PM