MARCH 20, 1997 SOUTH COAST & VANCOUVER ISLAND WEATHER: First day of spring and the other good news is that it will cool off a bit. Freezing levels went over the top at 2500m but snow still fell at highest elevations up to 1m of storm snow in the Whistler area. Very strong south west winds during peak of the storm. Temperatures reported from Coquihalla were maximum 3, minimum .1 at 1800m. Blackcomb reported a maximum of 1degree at 2000m. Some cooling and relief for the weekend. SNOWPACK: Very poor snowpack stability in the past 36h caused by a combination of warm temperatures, strong winds and heavy precipitation with rain to high elevations. Rain soaked snowpack in the Coquihalla area has resulted in some avalanches releasing to ground on rock slabs. In the Garibaldi and Duffey Lake areas a dense slab formed over colder low density snow. The slab has good propagation characteristics at higher elevations and when running full path is gaining volume with moist snow at lower elevations. Some cooling will contribute to fairly immediate improvement in stability at lower elevations while the slab will remain sensitive at higher elevations. AVALANCHES: A major avalanche cycle for the last day of winter. Size 4 avalanches were reported from the backcountry adjacent to controlled areas and one covered the road that had not done that for 11years. DANGER: CONSIDERABLE danger with a special word of caution about isolated areas that may not follow the general pattern of much improved stability due to the cooling. TRAVEL ADVISORY: Watch closely for the weather change. On the last day of winter we could have expected cannibal snow but instead we got cannibal rain which ate up the snow at lower elevations. In the alpine a full range of winter conditions prevail and a sunny break will see lots of activity on south aspects. BULLETIN SPONSORED BY: ALPINE CLUB OF CANADA - VANCOUVER SECTION NORTH COLUMBIA WEATHER: A major storm for the last day of winter and it included full winter characteristics with up to 50cm of snow a few days ago and ended with a good dose of rain up to 2000m. Near Blue River at Mt St Anne the maximum temperature was 2degrees while at Mt Fidelity the maximum was 1.5degrees. Winds were strong from the south-west so the most snow transport was into north and north-east aspects. The weather forecast for the weekend is for some cooling and light snow amounts at higher elevations. SNOWPACK: Rain soaked snowpack in the lower alpine elevations and a dense slab in the higher alpine. The slab had good propagation characteristics. Due to the difficulty of getting observations during the storm it is not known what the slab ran on but it is likely to have started on low density snow and perhaps stepped down to older surface hoar layers. Mid-pack temperatures before the warming and deluge were in the -4 to -5degree range on a south aspect. Expect those temperatures have warmed up a bit but that will be an important field observation to be making now. The new slab in the higher alpine may be over 1metre thick so that heavy new load needs some time to settle out. AVALANCHES: Major avalanche cycle over the past 36h. A skier accidentally triggered an avalanche in Glacier Park before the height of the cycle. There was virtually no backcountry travel on Wednesday so there were limited observations there. Highways operations reported large and frequent avalanches both natural and with explosives control. DANGER: HIGH danger while the intensity of the storm cycle eases off, the danger may drop a grade to CONSIDERABLE if the forecast cooling arrives for the weekend. MARCH 20, 1997 SOUTH COLUMBIA WEATHER: The last storm of the winter certainly went through with a bang; every howitzer, rifle and hand charge operator was busy blowing things up and getting good results. People are out clearing off their storm boards and emptying the rain gauge, everything got filled up. Fifty centimetres of snow was an average value in the alpine before the rain set in with 10-30mm of rain being reported up to 2150m. SNOWPACK: Rain soaked snow to middle alpine elevations produced a rapid increase in load on colder low density snow which created a very poor stability snowpack. Mid pack snow temperatures on Wednesday were in the -2 to -5degree range so some warming required before we reach an isothermal snowpack. AVALANCHES: Well that was classic direct action avalanche activity if ever you want to see it. Smugglers Ridge ran naturally while being observed from the hut by the Park Ranger, a memorable experience. The crown was 50-100cm deep and the fracture line ran the entire ridge line. An equipment operator, south of Nakusp, was hit by an avalanche that ran from a fresh cut block and injured the operator with broken glass. DANGER: HIGH danger with a reasonable expectation that the danger will drop to CONSIDERABLE over the weekend with cooling. TRAVEL ADVISORY: Although the danger will drop if the forecast weather comes there are going to be isolated areas that may still hold the big slab that has long and deep fracture characteristics if it releases. BULLETIN SPONSORED BY: ALPINE CLUB OF CANADA - VANCOUVER SECTION ROCKIES WEATHER: Rain in the Rockies, just in case you thought it only happened on the coast in winter. The precipitation has eased of on Thursday morning. Accumulations don't need to be as great on the weaker snowpack to get avalanches happening and so the Rockies ran true to form on that criteria. Maximum temperature in Assiniboine on Wednesday was 7 (that's plus 7) degrees and 4degrees at Marmot. Fifty centimetres of snow in the Jasper area. SNOWPACK: Major new storm load, warming with rain to 2000m was a good natural trigger for the poor stability snow and in other areas the practitioners of the big bang theory were putting their theory into practice with explosives and getting good results. That is always a good snowpack test. At Norquay an isothermal snowpack at 2000m on south east aspect is the first reported isothermal snowpack of the season. In the Fernie area, the top 1m of the snowpack is moist while at the north end of the region near Marmot there has been moist heavy new snow sitting on the weak base layers. AVALANCHES: Widespread avalanche cycle up to size 3 avalanches, some of these stepping down to the older weak layers. DANGER: HIGH TRAVEL ADVISORY: The scale and frequency of natural avalanches may ease of for the weekend but with the inherently weaker Rockies pack the instability on the weak base will probably persist through the weekend. If it does tighten up a bit more consider that a bonus but careful local evaluation will be needed to assess this improvement. There wasn't much travel out of the alpine huts. At Assiniboine the day was spent digging out and knowing the avalanche danger was extreme.