FEBRUARY 24, 1997 SOUTH COAST & VANCOUVER ISLAND WEATHER: Very warm alpine temperatures for late February, up to 5degrees on Sunday at over 2000m. There may be some cooling by Tuesday but it is hard to see any snow in this weather forecast. A little bit of cooling overnight but only just to the freezing mark. Direct radiation and strong sun on Sunday is now giving way to more cloudy conditions. SNOWPACK: Poor stability in surface layers that are getting lots of sun and warming. Surface hoargrows by night and survives in high shaded aspects by day. General settlement and strengthening of the deeper snowpack but some slab instability exists. The slabs are reported to have 40-70cm thick crowns. A moderate compression test is repeatable about 35-60cm down on a one finger layer. Isothermal snowpack below 1500m. AVALANCHES: Lots of point releases and loose snow avalanches which are to be expected. More of a concern are the slab releases triggered by cornice and skier resulting in at least one partial burial. DANGER: CONSIDERABLE, in the alpine TRAVEL ADVISORY: Watch for spring like conditions and the isolated slab instability. This Avalanche Bulletin is prepared for the Canadian Avalanche Association, a non-profit, non-government Society based in Revelstoke BC. Just before the financial year end is the time to pass the hat and ask for contributions. Thanks to all our mentioned sponsors and individuals who support this project. Our address is Box 2759, Revelstoke BC Canada V0E 2S0. Please read the north Columbia report for more information about the 800service. BULLETIN SPONSORED BY: ALPINE CLUB OF CANADA-VANCOUVER SECTION NORTH COLUMBIA WEATHER: Warming, southerly winds and virtually no precipitation were the main weather features of the weekend. Varying thickness of afternoon cloud had, in some cases a shielding effect and in others enhanced the solar radiation. Temperature range with a freezing level at over 2000m during the day and down to -2 to -4degrees at night was typical. More cloud and possibly light precipitation on Tuesday. SNOWPACK: Two dates to keep in mind are 11 November and 12 February, especially in the northern part of the region. Last weeks storm snow continues to settle out, quite rapidly in the present temperatures with nearly moist snow in the top 10-20cm up to 1900m on south aspects. Until the daytime temperatures cool expect the warming trend to continue higher up the mountain. Poor stability in that moist snow on steep south aspects. The more difficult problem is the 12 February layer and much more isolated, the 11 November. AVALANCHES: Large avalanches over the weekend in the Valemount/Blue River area, both natural and with explosives. Cornice failure also being triggered by warming. On Saturday a skier was buried in the Rogers Pass area. He was skiing alone and his hand sticking out was observed by another group passing by. Lucky boy. DANGER: CONSIDERABLE, with special care in route finding and lots of field tests. TRAVEL ADVISORY: Good quality snow still on north aspects from 2000-2500m, on the 25degree terrain it seems reasonably safe. Any comments please on the 800number service? We get some contributions directly for this service but not enough to pay for it. Next winter we may have to go for a 900number at the lowest possible charge, don't forget that the phone company makes the most money out of that type of service. That's why they came to our office suggesting we change. Please read the note above in the Coast Range comment and thanks for your support. FEBRUARY 24, 1997 SOUTH COLUMBIA WEATHER: A little cooler than the north Columbia with minimums down to -12degrees but strong sun effect on south aspects in the daytime. No precipitation over the weekend and only very light winds, not contributing much to snow transport. Height of snow in alpine study plots is in the 3metre range. Weather forecast for the Bulletin period calls for most of the precipitation to be north of the Golden/Vernon line. SNOWPACK: New surface hoar, rapid settlement of last weeks storm snow and poor stability of sun effected near surface layers are three notable characteristics right now. Surface hoar 1metre down is a concern in the Nakusp area. Further south the snowpack is settling well and dense recent storm layer are reasonably well bonded. Snowpack temperatures on south aspects would be a good thing to keep an eye on now that isothermal has been seen at lowest elevations. In some areas surface hoar is growing at high ridges and hopefully will get blown or melted away before the next storm. AVALANCHES: Helicopter bombing produced avalanches to size 3.5 in the Bobbie Burns area. Skiers accidentally triggered avalanches outside the Red Mountain ski area. Lots of natural loose snow avalanches on sunny aspects. DANGER: MODERATE, going to HIGH on sunny south aspects in the afternoon. TRAVEL ADVISORY: This region seems to have the best stability conditions but the usual caution is advised. By international standard the avalanche year end is September 30 but the financial year of the Canadian Avalanche Association, the non-profit, non-government Society that produces the Bulletin is March 31. So if you have done your tax return and feel like making a contribution to this project, please send a donation to Box 2759, Revelstoke BC Canada V0E 2S0. Thanks to all our good commercial, provincial, clubs, snowmobile manufacturers and others who make this possible. Free CAA decal with your donation! ROCKIES WEATHER: It is near the end of February so the fear of the -40degree cycle is almost over for the winter. More wind effect in Jasper Park, generally light winds in ski touring elevations. Minimum temperatures down to -15degrees at night and going up to -2degrees at 2000m in the daytime. Southern Rockies can expect to stay dry but the central and northern areas may get a little. SNOWPACK: Alpine snowpack in the Kananaskis is still feeling all the effect of that wind and sits on the proverbial depth hoar base. The warming has softened the surface layers a little and some basal rounding has started but strength of the snowpack has not improved much. In the Fernie/Waterton/Westcastle triangle the south aspects sluff easily in the warm part of the day. Stability ratings range from good in the Jasper area to fair around Lake Louise and unusually in the Rockies no one reporting poor stability right now. AVALANCHES: Numerous avalanches up to size 2 but nearly all by the fairly predictable surface snow instability. An avalanche involvement in Waterton Park resulted in the person caught being on the surface and uninjured. DANGER: MODERATE, by comparative Rockies standards. TRAVEL ADVISORY: From our observers, there's not a lot of mention about the depth hoar base but it is not forgotten. Please comment on the 800number service. We may have to go to a 900service next winter. Although we get great support from clubs and individuals it is not quite enough to pay for 800. There are a number of other ways to get the Bulletin for free. Spring meeting of the Canadian Avalanche Centre on 7 May. There will be more information about this after March 17. BULLETIN SPONSORED BY: ALPINE CLUB OF CANADA-VANCOUVER SECTION