Using Your Donations to Support This Bulletin SOUTH COAST REGION WEATHER: The ridge of high pressure that has remained stationary for most of this past week is now breaking down. A weather system off the BC coast is slowly moving inland and was just offshore from the South Coast region Monday. As the system approaches, we should see an increase in the alpine winds as well as light to moderate accumulations of snow. The southerly flow will increase freezing levels to 1000 meters. By late Tuesday or Wednesday we should see more snow, as a very intense low pressure system is forming out in the Pacific. Looking at the forecast for later in the week it sounds like there will be more snow as well. SNOWPACK: Most of the areas throughout the south coast region report a well settled snowpack, with no significant weaknesses showing up. With the last week of clear nights and cold temperatures, the alpine snowpack continued to gain strength. Those clear nights promoted surface hoar growth at most elevations and aspects, the cold temperatures promoted faceting near the surface. Soft thin wind slabs are about the only problem to watch out for right now. As the surface hoar gets buried, surface instabilities will develop. AVALANCHES: Small releases on south facing slopes from daytime heating, other wise no other avalanche activity being reported at this time. DANGER: ABOVE TREELINE - Moderate, increasing BELOW TREELINE - Low, increasing TRAVEL ADVISORY: With the approach of changing weather conditions, snow, wind, and rising freezing levels, one should expect a rapid change in the current snow stability. It's a good idea to perform some snowpack stability tests before getting too committed on a slope. If the new snow forms a slab due to temperature settlement or wind, expect widely propagating slab avalanches to be likely. NORTH COLUMBIA REGION WEATHER: A ridge of high pressure has maintained mostly clear and dry conditions across the North Columbias over the weekend. Light winds have prevailed, with temperatures bottoming out at -18 at the higher elevations. This ridge of high pressure is now showing signs of breaking down, resulting in light snow Monday. Slightly higher snowfall accumulations are expected for the Cariboo and Northern Columbias. The remainder of the week sounds unsettled as another very intense low out in the Pacific comes inland. It sounds like more snow for late Tuesday and Wednesday followed by a weak ridge on Thursday. SNOWPACK: Concern remains for lingering buried surface hoar layer instabilities within the top 35 and 50 cm of the snowpack. Currently the upper snowpack is showing signs of faceting due to cold temperatures in the alpine, surface hoar as large as 3cm is being buried by the new snow. The remainder of the snowpack is generally well consolidated. AVALANCHES: Radiation triggered point releases have been occurring in many areas. A few size one avalanches being reported, lower elevations on surface hoar. DANGER: ABOVE TREELINE - Moderate, increasing BELOW TREELINE - Low, increasing TRAVEL ADVISORY: Pay close attention to snowfall amounts and winds, with current widespread surface hoar, snow stability will play a major factor for backcountry travel this week. More load will affect the strength of the buried surface hoar layers, and the present interface being buried will be a significant instability on shaded slopes if a slab forms over it due to wind or temperature settlement. Steep south facing slopes will have a poor interface bond under the new snow due to sun crusts. SOUTH COLUMBIA REGION WEATHER: A ridge of high pressure has kept conditions clear and dry over the weekend, with calm to light west winds and cooler temperatures. The ridge of high pressure began to break down Monday as a minor Pacific low came onshore. The remainder of the week should remain unsettled, with more snow and wind. SNOWPACK: North aspects are showing a reactive surface hoar 30cm from the surface. This instability appears to be very reactive to ski cutting on unsupported features in elevations of 1800 meters and below. Solar radiation effects have been observed in steep S and W facing terrain, with a suncrust having formed in these places. All most all operators are reporting wide spread surface hoar development above and below treeline, so the new snow is expected to form a weak initial bond, particularly if wind is strong enough to cause drifting. AVALANCHES: Mostly solar radiation triggering point releases have been occurring in many areas. DANGER: ABOVE TREELINE - Moderate, increasing BELOW TREELINE - Low, increasing TRAVEL ADVISORY: A variety of interesting conditions have formed on the surface of the snow over the last few weeks. Right now there is surface hoar, suncrusts, and windslabs in various locations. With snowfall in the forecast over the next few days, stability of the surface layers is bound to deteriorate, as the new snow will have trouble bonding to these surfaces. Pay close attention to the weather this week, as heavy snow, moderate to strong winds or warming temperatures, if they materialize, will play a significant role in snowpack stability. ROCKIES REGION WEATHER: The ridge of high pressure did slump to the east by Sunday, but it should still remain the predominate weather picture giving a little more sunshine and cool temps. Clouds and flurries can be expected as a frontal trough moves into Alberta by Tuesday evening. The remainder of the week should remain unsettled, as the Pacific weather systems start to line up off the BC coast and march across the province. There is the potential for a major snowfall event to occur late in the week, although weather forecasters were uncertain Monday if this potential would materialize. SNOWPACK: Thin windslabs predominate in the alpine and into some treeline areas. Solar radiation has produced suncrusts on south facing slopes and the cold overnight temperatures continue to promote faceting. There are two distinct layers that are still of concern in the lower snowpack. The Y2K buried surface hoar layer is at mid snowpack and the November raincrust mixed with facets is found near the bottom. Last week an avalanche involvement that occurred on the November crust after the new load of powder was a very close call. The problem with deep persistent instabilities is they are much more dangerous if they do fail, as the resulting avalanches are almost always large slab avalanches, with great power and the potential for deep burials. In the Fernie area, recent storm snow has settled out, and the shear 20cm down is no longer reactive to ski cutting. Windslabs are still found in the alpine, up to 25cm thick in isolated areas. AVALANCHES: Avalanche activity is quiet at the moment in the Rockies, some natural avalanche activity reported from near the Banff/Kootenay boundry area, size 1.5 on an East aspect. DANGER: ABOVE TREELINE - MODERATE, increasing BELOW TREELINE - LOW, increasing TRAVEL ADVISORY: During this time of the year, solar radiation effects become much more pronounced and important. With the arrival of new snow one day and sunshine the next, sun exposed terrain will lose strength rapidly as the sun beats down on it and the temperatures rise. While the weather conditions are slated to change this week and the forecast pattern remains unsettled, caution in route selection is still the best advice.