SOUTH COAST REGION WEATHER: Plenty has happened weather wise this week. The region saw 25cm of storm snow added to the alpine, and the dreaded rain lower down. Thankfully, winds remained light to moderate even in the high country. Wednesday morning, alpine temperatures plummeted with the passage of a cold front, forming a crust on the surface of the storm snow. The weather forecast calls for moderating temperatures and unsettled atmospheric conditions, which will tend to keep winds blowing up high, and produce periods of sun interspersed with cloud and moisture activity. The freezing level should climb from valley bottom to the 1000m elevation range. SNOWPACK: We started the week with a wind slab in the alpine, which was buried under the 25cm of storm snow later in the week. On top of that sits a crust, which will persist on shaded slopes and was already under 10cm of light density snow in some places by Thursday. The mid snowpack has not shown to be a problem, although the weather has limited the ability to take readings in the alpine, leading to the possibility that buried surface hoar problems are still lurking down a metre or so in the alpine. AVALANCHES: A wind slab related avalanche claimed the life of one skier early in the week, before the majority of the storm snow arrived. Some natural activity was reported mid week, failing within or just under the storm snow. This interface had settled and improved by Thursday, but ski cutting and explosives control still regularly gave results to size 2.5. Below treeline, widespread isothermal naturals were reported, and this is likely to continue. DANGER: ABOVE TREELINE - Considerable, areas of High BELOW TREELINE - Considerable TRAVEL ADVISORY: Below treeline will be increasingly problematic, particularly late in the day on south and west facing aspects. The new snow predicted will not likely bond with the surface crust very well initially. NORTH COLUMBIA REGION WEATHER: The interior saw a good deal of very poor weather this week, heavy snow, rain to as high as 1100m, followed by a cold front passage Wednesday. Winds stayed reasonable until the cold front approached, jumping to 40km/hr in the alpine early Wednesday. The weather forecast calls for classic spring conditions, some sun, some rain and snow, and moderate temperatures. A disturbance will track over Saturday, followed by a ridge of high pressure building by late Sunday. The freezing level will climb all weekend, rising to 1000m. SNOWPACK: The alpine has received close to a metre and a half of snow over the last 10 days. Wind slab is found in most exposed areas, and a soft slab exists even in sheltered areas due to the cooling which occurred as the cold front passed. So much snow has been added to the snowpack lately, and the weather has been so poor, that detailed snowpack analysis has been difficult. The situation at the buried surface hoar layers now down well over a metre is still unknown. AVALANCHES: Although no detailed observations were possible mid week due to heavy cloud cover, observers did report being able to hear naturals rumbling during the storm. Solar radiation can be expected to trigger storm snow releases naturally, and the potential for human triggering will be high early in the weekend, improving if the weather forecast holds true. DANGER: ABOVE TREELINE - High, improving BELOW TREELINE - Considerable TRAVEL ADVISORY: Expect isothermal conditions to develop below treeline due to all the rain bringing snowpack temperatures up to near zero. Treat the alpine with respect. Stability will improve but human triggered events may produce quite large avalanches. Expect cornice fall activity. SOUTH COLUMBIA REGION WEATHER: The weather this week was much more pleasant in the South Columbias than in the North Columbias. Moderate amounts of snowfall were added to the alpine, which fell as light rain lower down. Winds remained light to moderate, except in the Purcells, which saw moderate to strong flows Wednesday. A cold front passed through Wednesday affecting the north end of the range, while in the south temperatures remained mild. The weather forecast calls for a mix of sun and cloud, moderate temperatures, and occasional light moisture. SNOWPACK: Although observations are limited due to weather, varying conditions are being reported. The Purcells have a wind slab on the surface. Crusts are often found and are sometimes breaking down with solar heating and reforming overnight. Buried surface hoar layers are much nearer the surface here than in the North Columbias, mostly found down about 85 and 110cm. Isothermal conditions will predominate on low elevation south facing slopes. DANGER: ABOVE TREELINE - Considerable, improving BELOW TREELINE - Considerable in the afternoons TRAVEL ADVISORY: Watch for solar heating changing conditions during the day. Cornice fall will be likely this weekend, and may trigger deeper layers on the slopes below. If overnight temperatures start to remain above zero, expect the snowpack to move rapidly toward isothermal. The Canadian Avalanche Association is planning a New Technology seminar at the Sandman Inn in Penticton May 2nd, featuring factory representatives for many new digital beacons, RECCO rescue system, ABS balloon packs, and the Avalung vest. ROCKIES REGION WEATHER: The cold front tracking through BC moved across the central Rockies Wednesday, leaving about 25cm of new snow behind in the alpine. Winds were light to moderate mid week, picked up sharply as the cold front moved in, then subsided again as it passed. The snow falling Thursday is predicted to end Friday, with mixed cloud and sunny periods Saturday. Sunday, skies are predicted to clear as a ridge of high pressure builds. SNOWPACK: Windslabs predominate in the alpine, although they are buried under a soft slab from the snowfall which continued after winds died down. Lower snowpack weaknesses are beginning to fail with human triggers and propagate long distances through the snowpack, at times triggering slides on steeper terrain features nearby. The November Crust was reported as a failure plane earlier in the week. AVALANCHES: Very little natural activity has been observed, although the occasional slab to size 2.5 has been reported. Human triggered events have occurred recently from Jasper all the way south to Fernie, and occasionally involve lower snowpack layers. Isothermal conditions are being reported on south aspects at low elevations. DANGER: ABOVE TREELINE - Considerable BELOW TREELINE - Moderate, deteriorating in the PM TRAVEL ADVISORY: Solar heating problems will become increasingly more likely throughout the weekend. Watch for the overnight low remaining above zero, which signals full isothermal conditions are likely soon afterward. Cornice fall this weekend is likely, and may trigger deeper instabilities as it hits the slope below. Some ice routes will be falling apart now, causing immediate danger to climbers but also creating the possibility of triggering slabs below.