The Canada Avalanche Centre urges caution this weekend as a large swathe of the B.C. backcountry is under a special avalanche warning.
The warning extends from the Kootenays up through the North Rockies. The Sea-to-Sky and Northwest Coastal mountains are not included.
A clear, dry spell from late January to early February created a weakening effect on the surface of the snow said public avalanche warning service manager Karl Klassen, Thursday. "Now that surface is buried and left us with a very complex upper snowpack, with a number of weak layers."
Mr. Klassen said that there may not be a huge avalanche cycle during this critical period, but the warning is in place so that people don't assume the risk is less than it is. The snowpack is conditionally stable but won't hold any more stress that's added to it.
"If you don't know anything about the ocean but you see 40 ft. waves coming to shore, you're not going swimming. With this, it looks like its stabilized when it's likely not, the underlying riptide still exists," he said.
"Add a snowmobiler or skier to the mix, especially if it's a warm and sunny day, and that will be the most likely to create an avalanche."
Since Feb. 15 there have been more incidents of people being surprised by avalanches, he said. It's best to stay out of the area, unless you have local knowledge or expertise to recognize avalanche terrain, he said.
In the 2010-2011 season there were 11 avalanche fatalities in B.C., down from a 10-year average of 14. There have been four deaths this winter season.