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Backcountry Advisory

Pick a route that will avoid exposing yourself to any steep sun-baked slopes

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As of Wednesday, April 5

Alpine: LOW increasing with exposure to the sun

Treeline:LOW increasing with exposure to the sun

Below Treeline: LOW increasing with warming

Travel Advisory: The new snow layers that we received periodically during the past week have settled in and all aspects except due north in the high alpine terrain have had some degree of solar effect. Fast spring travel conditions early in the day will rapidly deteriorate with exposure to the sun. On sunny days, pick a route that will avoid exposing yourself to any steep sun-baked slopes during the heat of the day. Cornices have reached a critical mass and are breaking well back onto the flats – give yourself lots of leeway if you are traveling along the ridgelines and run out zones.

Avalanche Activity: Widespread loose surface sluffs have periodically occurred this week as the new snow layers moistened with exposure to the sun. Once a melt-freeze crust became established, these surface instabilities reappeared as the surface crust broke down with daytime warming and the solar effect, but with less frequency. If the flurries that are forecast to arrive during the next few day’s materialize, this cycle may again repeat itself.

Snowpack: Typical spring melt-freeze conditions prevail on all but due North aspects above the 2,200 metre elevation. Any clear nights and associated radiant cooling will continue to result in the development of a solid melt-freeze crust on any sun-exposed slopes.The underlying basal layers of the snowpack are generally quite strong with no persistent weaknesses observed. Lower elevations below treeline are becoming progressively more isothermal.

Weather: Sunny skies will give way to increasing cloud cover this afternoon and overnight tonight as a weak system approaches the coast. Flurries may develop by Thursday morning, with a chance of flurries continuing at times on Thursday night and Friday morning. The freezing level will rise to about 1,900 metres today, and then fall to around 1,500 metres tomorrow afternoon. Not much confidence in the long range models, but right now it looks like the low pressure centre that has been parked offshore will continue to periodically spawn weak disturbances that will arrive onshore, interspersed with sunny breaks.

Conditions may vary and can change rapidly. Check for the most current conditions before heading out into the backcountry. Daily updates for the areas adjacent to Whistler/Blackcomb are available at 604-938-7676, or at www.whistler-blackcomb.com/weather Whistler Mtn. Snow Safety

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