Avalanche risk high but expected to settle 

Canadian Avalanche Centre to provide more detailed reports

Canadian Avalanche Centre forecaster Ilya Storm is urging caution in the short term, but doesn't see any issues with the early-season snowpack that are going to persist through the rest of the season.

"We have had three years of difficult snowpacks in B.C. which have been really challenging, both from a forecasting and from a public safety point of view," he said. "It's been harder to make good decisions in the mountains, and to match the types of trips that people are doing to the conditions."

The risk in the Whistler backcountry area was rated as High Tuesaday, dropping to Considerable later in the week, but otherwise Storm says they're seeing a more typical snowpack for the province.

"We get storms through, we have a (avalanche) cycle, it clears up and we get a break for a few days - then repeat," he said.

The current risk was elevated by the Arctic outflow reported from about Nov. 20 to 24, which brought cold temperatures and high winds to the Coast Mountains. That dried out the snow and created a layer of hoar frost, which was compressed under close to a metre of new snow in the following week. While that created a weakness, Storm expects that it will consolidate over time.

"I think this one is going to disappear," he said. "It's disappearing right now. We won't really know for a little more time, but the way to heal layers like this is to put a whole lot of snow on top of them to create pressure - what we call pressure centring - where it gets all squished together and the snow on top warms it up to create a nice, even-temperature snowpack.

"The best thing for the South Coast right now is nice consistent snowfalls, that's the way to build a good snowpack, with nice, cool temperatures. The wind and cold and minus-20 for two weeks doesn't do us any favours."

So far most of the avalanche reports to the CAC are the result of avalanche control at ski areas, although he says some reports are starting to come in related to backcountry avalanches.

From 2000 until April 29 this year, there were 146 avalanche fatalities reported in Canada, an average of 14.6 deaths per year. There have been spikes, such as the 27 killed in avalanches in the 2002-03 season, including 14 skiers and snowboarders in two large slides. Fatality numbers were dropping until the 2008-09 season, when 24 avalanche deaths were reported - 19 of them involving snowmobiles.

In fact, the number of fatalities among backcountry skiers/boarders has been falling, while the number of snowmobile deaths is up for the province. Snowmobiles account for 41 per cent of avalanche deaths in the last 10 years, compared to 29 per cent for backcountry skiers. The remainder of deaths are divided among out of bounds skiers, mountaineers, mechanized skiers (using snowmobile access for the most part) and "other."

The Canadian Avalanche Centre, working with the province of B.C., has been working to improve communication with all backcountry users, with an emphasis on snowmobilers.

To that end, the CAC has released new tools for this season. One is the Avaluator 2.0 update, which is a set of decision-making tools for entry level backcountry users. Another is the CAC Fieldbook, which is for more advanced backcountry users.

"Basically, it's the people who take a weekend avalanche course that are going to use the Avaluator, which is a good decision support tool for people getting started in mountains and venturing into avalanche country," said Storm. "We hope those people will gain knowledge and experience and grow out of it, and may take more advanced avalanche courses.

"That's where the guide book comes in. It's a series of prompts for types of things that they should be looking out for, the types of observations that people should be making. It helps people mimic professional decision making."

As well, in the near future the CAC will be including more information and observations with their avalanche bulletins.

"People who have a little more training and more experience will be able to drill into the bulletins and forecast... and see the summaries and data behind the forecast," explained Storm. "It's something we've been doing as part of our bulletin creation process and we figured that by making it publicly available it will serve some people's needs. Right now we're just figuring out how to throw the switch and make it more public."

Public avalanche bulletins are posted online and updated a minimum of three times per week. For more information visit www.avlanche.ca.

 

 

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