Backcountry Advisory As of Feb. 24 The vicious storm cycles have continued to batter us this week. The pattern persists — maybe one day in the week when the sun threatens, and then the next onslaught sets in. The strong winds and the big dump on Tuesday night were the predominant avalanche related weather features for the week. The winds made for extremely variable conditions in the alpine — lots of scoured slopes on south aspects, and large pockets of wind slab on north aspects. As we have cautioned before, be extremely wary if you suddenly go from an obviously scoured surface to a deep pillow of wind transported snow. You may stay on the surface of the slab, but a quick probe may indicate that it is soft and hollow underneath. Often the slab will be triggered near to its transition with the scoured surface, but will become more sizeable as it pulls into the meaty part of the slope. The resulting chunky debris will not be very forgiving! The season's storms have been generally staying cool enough to keep the snow falling at the lower elevations. As a result, many of the popular logging slashes have become more filled in than usual. That means that they are also more enticing. You may never have seen an avalanche occur in these slashes. All of the little trees sticking through the snow surface provide good anchors and help to keep the slab from moving. As these anchors become covered, they are no longer effective, and the slash starts to look like another alpine bowl. Your safe, low elevation terrain may have become a new avalanche start zone. Let the storm snow settle before you tackle any exposed terrain. We are still not seeing any deep instabilities in the snow pack, but the periods of high winds and heavy snowfall have created weaknesses that are well below the surface in many areas. The forecast is calling for another system to arrive late Friday and carry on into Saturday. The longer range outlook puts us on the northern edge of the main flow, which should bring cool temperatures and light amounts of snowfall into the middle of next week. As of Feb. 24, the avalanche danger is rated as HIGH. Conditions may change, so check on the most current information before you head out. Call 938-7676 for the daily avalanche bulletin that describes conditions in the terrain adjacent to the Whistler/Blackcomb ski areas.
