Jan. 13, 2010 - Issue #743: Broken Embraces
White science
Inside Canada's avalanche "think tank"
Which is kind of appropriate. At the moment, he's trying to reconcile multiple data and field observations into an accurate prediction of avalanche safety for the South Columbia/Kootenay region.
The walls are plastered with maps of various BC mountain ranges. In front of him lies a table scattered with paper printouts, a mouse and keyboard and a large projection screen displaying the latest data.
Outside, a front is definitely blowing in. Storm's colleague, Mark Bender, sits silent in a chair beside the window, brooding on his own notes. "I don't know about you," Storm says, "but I'm scared."
Storm and Bender have just gotten off the phone with an Environment Canada meteorologist, who had briefed them on details of the storm system passing through the region. Something about the way she mixed in words like "probably" and "hopefully," says Storm, has him worrying that snowfall might exceed predictions, leading to a high avalanche danger cycle.
The CAC's avalanche bulletins from the previous day had already set the risk as "considerable" for treeline and alpine regions. But with some added precipitation and wind loading on a persistent weak layer, or "PWL," things could change quickly.
If that happens, Storm says, "All bets are off."
For perspective, there's nothing like being in the eye of the storm. The mountains surrounding Revelstoke average 18 metres annual snowfall, making it a popular base for touring of all kinds.
The CAC building sits just off a parking lot on Mackenzie Ave, Revelstoke's main street, behind the twin grizzly statues guarding the entrance to downtown. It has a benignly pleasant exterior with vines growing up taupe walls. A rectangular storefront sign hangs above the door and on the side of the building a square, billboard-style logo—two cascading, parallel white lines on a red background.
The reception area has several racks of avalanche-education books and materials, promotional T-shirts and a display case. Beyond the reception the main floor looks rather bare—save for the large cannon.
The Avalauncher, as it's known, is used in avalanche control to propel large torpedoes to inaccessible targets. It sits in the centre of the floor, a reminder of just how powerful human impact can be in the mountains.
In the cloistered quiet, the Avalauncher speaks silent volumes. If I close my eyes I can imagine that deep "whumpf," the explosive aftershock and the mountains shaking beneath my skis as snow rumbles down a nearby slope.
Though the CAC is relatively new it has had a significant impact. The centre, a non-government, non-profit entity, was founded in 2004. Since that time it has filled a critical void in national public safety services to a growing demographic of mountain users. In addition to the Revelstoke office, the CAC has a North Shore (Vancouver) satellite office and an independent affiliate in Quebec.
Avalanche bulletins are the primary public information product the CAC releases on a daily basis to alert backcountry travellers of mountain hazards, but they are far from the CAC's only effort. In addition to daily forecasts, the CAC administers public awareness efforts, coordinates training programs and supports snow science research.
Its website, avalanche.ca, is a key reference for many avalanche professionals and backcountry recreationalists. All told, the value of aggregating and repackaging the raw snow data for broad consumption has been estimated in the millions of dollars annually.
Many guides and backcountry users seek out this information—in particular, the bulletins—as a source of information for pre-trip planning. To Storm, this is invaluable.
"By the time somebody's in the parking lot, a lot of dominoes have fallen," he says. "The most important decision a skier makes might be in the living room that morning."
Which puts all the more pressure on Storm and his CAC colleagues to assess and convey the potential dangers to the broadest possible audience. Uninformed or uneducated backcountry users can put both themselves and others at risk. Though the CAC can't and shouldn't be held responsible for individuals' personal choices, "it's hard not to take every accident as a sign of failure," wrote the CAC operations manager John Kelly in an article published in Vue Weekly's December 24, 2009 issue.
Unfortunately, Storm grudgingly acknowledges, "Fatality data is some of the best we have."
Prediction is delicate work, and predicting avalanches is particularly tricky. As former US president George Bush Jr. might say, there are known knowns, known unknowns and unknown unknowns. Weather and climate variables, humidity levels, layer characteristics, terrain, slope aspect and human agency can all change snowpack traits by the hour or subtly over weeks, making it difficult to detect patterns or predict responses.
Even were forecasters to monitor every slope face in the mountains on an hourly basis, they couldn't guarantee 100 percent accuracy. There's no way to predict with full certainty how human intrusion will affect a given environment, or how the snowpack will react. The forecaster, says Storm, has to be "part detective, part scientist and part philosopher."
The forecasting session I am privy to is morning routine to Storm, Bender and the six other CAC forecasters who trade off shifts in the office with their other jobs in the field. A forecast session typically involves three forecasters and takes three to four hours per day. Cam Campbell from the North Shore satellite office has called in via Skype for today's session.
The team will pore through data from government telemetry stations, meteorological reports and snowfall trends. They also examine field observations collected from hundreds of national park wardens and commercial guides working for backcountry touring, cat and heli operations through a system called InfoEX. Finally, they track recreational user reports from the general public.
The standard morning agenda is to develop forecasts for each of nine alpine regions covering substantial parts of BC and spilling into Alberta—South Coast, North Columbia, South Columbia, Kootenay Boundary, South Rockies, Northwest BC, North Shore, North Rockies and Bighorn Country.
Beyond the immensity of the task, the rationale behind having multiple forecasters at every session is to make "diverse, group decisions," says Storm. Most of the forecasters have advanced degrees in addition to journeyman experience in the field. Storm, for example, has a master's in geography with a concentration in snow science. Given the wide range of expertise that the centre brings to avalanche safety and education, he characterizes the organization as a "think tank."
As they assess each region, Storm, Bender and Campbell debate different concerns, look up data on the fly and reference historic and current trends to reach agreement on danger ratings and the messaging that will go into each bulletin.
When conditions look unstable or the forecasters are having a particularly hard time getting an accurate picture of an area—as happens to be the case during my visit—they will call in outside expertise for additional information. The CAC is one of the few independent organizations that has a direct line to Environment Canada meteorological services.
For all the intellectual rigour and the intense scrutiny of scientific data, though, Storm admits that sometimes forecasters have to work on intuition. After years of backcountry guiding, he explains, you start to subconsciously recognize trends before they become obvious.
On this particular day, several areas that were rated "considerable" danger graduate up the scale to "high" danger, which means that both human and natural avalanches are likely. Having reached a decision, Storm, Bender and Campbell divide up the task of writing the bulletins and then disperse.
Over the next few hours, the forecasters will distill their findings into concise descriptions of conditions across the various mountain ranges, with messages on travel decisions, route finding and warning signs. A standard line during high-risk times is to warn against travel "unless you have professional level training and safety systems."
Very rarely will the centre advocate no travel whatsoever. Their purpose is to promote smart travel: with the right training and experience, users can consult the bulletins and make their own decisions. It's all about "managing the uncertainty" of winter travel conditions in the mountains.
With proper precautions, says Storm, there can be "recreationalists out there having a grand old time, doing everything right" even during times of significant risk—a message that often gets lost in traditional media reports sensationalizing fatality incidents.
Exposure to risk is a personal choice, but for those who choose to travel in avalanche territory there are ways to mitigate that exposure. That's where the CAC comes in, negotiating the shifting balance between human choice, awareness and backcountry safety. The known, and the unknown.
Forecasters like Storm are under no illusions. They know that the work they do is just the beginning, one window into the great expanse of the mountains. Peering out at the thickly blanketed town of Revelstoke, Storm shrugs. "Usually, [forecasting is] analytical," he says, "but sometimes you have to go with your gut." V
http://avalanche.ca
Forecasting REGIONS
avalanche.ca/cac/bulletins/regions
More stories in Snow Zone »
New comments for this entry have been turned off and any existing ones are hidden. We apologize for any inconvenience.
