Current CANADIAN AVALANCHE BULLETIN JANUARY 4, 1996 SOUTH COAST & VANCOUVER ISLAND WEATHER: Rain went high on the mountains on the 1st and 2nd of January. Not a pretty way to start the New Year in the snow business. But there has been a reasonable recovery. Freezing levels have dropped to near surface, light snow amounts have fallen since the rain and winds in the outflow situation have gone northerly in the alpine. The forecast for the weekend calls for another system to come onshore but temperatures should stay cooler and snow amounts light. SNOWPACK: Big, fat rain crust is the most obvious new feature for snow and skier stability. In the higher alpine this crust has a collapsing layer under it which should be carefully observed. It is producing some easy shovel shear test in some locations. Alpine snow stability is generally fair. Strong northerly winds have scoured windward slopes and built a slab on southerly aspects but it appears to be bonding reasonably well. The deeper pack is strong and the cooling has tightened up moist layers. Some faceting in the upper 10-15 cm is not a serious concern just now. Overall snowpack height is much below average so in the high alpine there might be some thin weak spots that should be watched for. AVALANCHES: Some cornice releases along the Musical Bumps, up to size 2. In the ski areas a few size 1-2 avalanches with explosives and ski control. DANGER: MODERATE. TRAVEL ADVISORY: Avalanche conditions have changed dramatically in the New Year especially in the Interior ranges. Be sure to check the Columbia Mountain bulletin if you are travelling there over the weekend. NORTH COLUMBIA WEATHER: Big dump of snow for a New Years present in most parts of the region. Revelstoke got over 50cm and it didn't end with rain so everyone is happy. Accumulations of around half a metre have now been moved around by northerly winds in the alpine. Temperatures remained below freezing at the surface and have now cooled significantly ranging from -5 to -15 degrees in the alpine. Weather forecast calls for continued cool temps in outflow conditions under a drier arctic airmass. SNOWPACK: Please note that there has been dramatice change in snow stability since the last report. The surface hoar sandwich mentioned earlier in the week has now got a major load on it. This will be very sensitive to skier and snowmobile triggers. The other intriguing characteristic about the current situation is that the surface hoar was not a widespread blanket in all parts of the region. Erwin said that many of the guides are saying "it's a minefield out there"... Dramatic settlements are heard and felt as the first process of stabilization is noticed in flat terrain. There was little testing possible in the alpine on Wednesday but at treeline the stability is still poor. AVALANCHES: Numerous avalanches up to size 3 with explosives and naturally from all aspects and elevations. DANGER: HIGH. TRAVEL ADVISORY: Avalanche danger may drop to CONSIDERABLE over the weekend but the unusually forgiving snowpack conditions that we have had all winter are gone. Although some of the skiing and snowmobiling conditions will be excellent, a very conservative approach is strongly recommended. Remember that New Zealand saying; "Avalanches are like wild pigs, okay as long as you don't get in their way." BULLETIN ALSO SPONSORED BY: MOUNTAIN MAGIC SOUTH COLUMBIA WEATHER: Not quite as much snow as the North Columbia but let's remember that it isn't only the amount of snow that falls but also the way it falls that makes for an active avalanche cycle. Twenty to forty centimetres in most of the region, freezing levels at the surface and light winds during the snow event. Clearer, colder weather with an arctic airmass getting established and strong northerly winds in the valleys. Maybe there will be some snow over the weekend but not forecast until Saturday evening. SNOWPACK: The holiday is over, we now have a difficult snowpack to work with. All through the Columbia mountains the surface hoar buried between December 28 and January 1 is probably going to be a feature for the winter. There are also some areas that got one layer of surface hoar buried by a few centimetres of snow then a new surface hoar formed on December 31 before being buried by the big snowfall. The surface hoar cycle started in the trees and finally got more established in the alpine. It varies greatly in distribution. Erwin told us that many of the guides are saying, "it's a minefield out there". The analogy seems very appropriate. AVALANCHES: Lots of avalanches both natural and with explosives up to size 3. Avalanches on the highway at Kootenay Pass and at all elevations in the backcountry. DANGER: HIGH, this may go to CONSIDERABLE as the danger from natural avalanches is reduced. But the potential for skier or snowmobile triggered avalanches will remain HIGH for the weekend. TRAVEL ADVISORY: Although some of the ski and snowmobile conditions will be excellent, a very conservative approach to all slopes is recommended. And for those who think the lunar cycle has something to do with snow stability there is a full moon on Friday. ROCKIES WEATHER: Another good snowfall for the Rockies in the first days of the New Year. Fifteen to thirty centimetres all the way down the continental divide from Jasper to Fernie, even Waterton has over a metre of snow in the alpine. Temperature range at 2000m from -5 to -15 degrees while the snow fell and now getting colder as the arctic airmass is well established. Winds in the alpine were 20-40kmh from the north and east at skiing elevations, much stronger in the high alpine. Little precipitation forecast for the weekend but the wind will be moving around lots of snow. SNOWPACK: New slabs of various density have formed. And with easterly winds in the Banff/Louise area, the slabs are building on unusual aspects. The late December surface hoar is now buried. This is the critical layer to be watching for and that means getting out the shovel and digging for a shovel shear test or Rutschblock. Probing with a ski pole or avalanche probe will easily miss this weakness. Easy shears reported on the surface hoar in Banff Park. Field test results on the facets are not as responsive as the surface hoar just now. The unusually deep Rockies snowpack is certainly making for a different approach to evaluation of snow stability in the Rockies this winter. Right now the deeper snowpack is not giving shears in field tests. AVALANCHES: There was a cycle of size 1-2 avalanches, mostly from explosives and ski control. There was not too much natural activity observed but visibility was limited. DANGER: CONSIDERABLE. TRAVEL ADVISORY: Avalanche conditions have changed dramatically in the New Year. In the Columbia Mountains the danger is higher than the Rockies, be sure to check the Buletin for that area if you are travelling to the Interior. [Submitted by: Canav (canav@mindlink.bc.ca) Thu, 04 Jan 96 12:13:23 -0800]