~A guest blog post by ADGISer, Gabe
Last winter, I was at the top of a run facing northeast at Kootenay Pass with six friends discussing our descent and the possibility of an avalanche. The Canadian Avalanche Association puts out daily avalanche bulletins, or forecasts, for broad regions across Canada. Kootenay Pass is officially in the Kootenay-Boundary forecast region. The bulletin area covers many different mountain ranges where weather patterns are unique to each mountain. I read the avalanche bulletin for the Kootenay Boundary region before heading out that morning. The bulletin that morning had a special notice for this area that described slopes that face northeast as having an exceptionally high probability of producing an avalanche, either naturally, or triggered by a skier on the slope. We all agreed for one of us to cut across the top of the slope to perform a ski cut and then we would dig a pit on the slope we were going to ski. The ski cut did not produce any results. We dug a pit in the snow and were confident in the snowpack that it would not slide. The special bulletin was still in the back of my mind but local observations trumped the bulletin and the special notice.
A local avalanche forecast for this particular slope on this particular day would probably not have included that special bulletin and would most likely be very different than the avalanche forecast for the Kootenay Boundary Region.
Each slope is unique to the set of conditions for an avalanche to occur. Many variables go into producing the right conditions for an avalanche. The GIS world has been working on trying to model avalanche slopes and combine that with historical data and weather models to produce avalanche forecasts. This has produced some very encouraging results. Through www.avalanchemapping.org, an online GIS resource has been created for analyzing avalanche slopes in the state of Colorado complete with an online interactive map for Colorado as well as historical information for each avalanche slope registered.
New Satellite technology producing high resolution optical satellite imagery has also been used through mapping differences in surfaces to detect where avalanches have occurred and their extant (research can be found here ).
Through these efforts, further snowpack analysis, and online collaboration of local observations collected through geodatabases, I feel that one day we will be able to get highly localized avalanche forecasts.
The decision was made for us to ski down this slope one at a time. We skied down and all had a fantastic run down. I would consider it one of the best runs of the year. It was a long descent with lots of soft powder that ended in a gentle slope through some old growth trees. Amazing!