How researchers are using computers to improve avalanche warnings

The outline of the size 2.5 avalanche in the Oasis area is visible in the center of this photo. Avalanche Canada reported the avalanche over the bowl, triggered remotely late Saturday morning. It was one of many avalanches reported over the weekend. /AVALANCHE CANADA PHOTO

By Laura Keil

A Grand Prairie-area man died after an avalanche swept him away in the Oasis riding area south of Valemount. His riding buddy managed to sled out of the avalanche and extricate him, but by then he was unresponsive. SAR has now recovered the body.

Avalanche Canada says snowmobilers were riding at the base of a 40-45 degree slope in a feature known as Bowl 3 in the Oasis area when the size 2.5 avalanche was remotely triggered on Saturday around 11:30 a.m.

Since December, Avalanche Canada has issued several warnings about weak layers and the “scary snowpack” that could trigger large avalanches without warning.

Ride with caution

Avalanche Canada said reports of human-triggered avalanches indicate the snowpack is very unstable in the area. “Stay on well-mounted and/or simple terrain. Be aware that deep instabilities are still present and have produced large recent avalanches. Carefully assess open slopes and convex rolls where buried surface hoar can be preserved. Avoid thin areas like rock outcrops where you are most likely to trigger avalanches stranding on deep weak layers. The recent wind has varied in its direction so watch out for wind slabs on all aspects.

Improve models and warnings

Pascal Haegeli, Research Chair in Avalanche Risk Management and head of the avalanche research program at Simon Fraser University, has spent the past 20 years studying avalanches and looking for ways to improve public safety through better modeling and better warnings. He works closely with Avalanche Canada, the national non-profit organization dedicated to public awareness of avalanche risk.

Part of his research involves developing evidence-based tools that help recreational enthusiasts and avalanche professionals make better decisions when planning and traveling in the backcountry in winter.

“I think we are facing a difficult situation that is unusual and that we haven’t seen in a long time, where we have weak foundations that are prevalent in most of the province. And these deep and persistent avalanche challenges tend to last a long time and it can be very difficult for people to deal with.

One of Haegeli’s projects involves using computer models that simulate the evolution of the snowpack based on the results of weather forecasting models.

“So we’re basically taking data from weather forecasts and putting it into a model to predict the evolution of snowpack in western Canada.

Part of their job is to correct the models if they stray from reality, thereby improving their accuracy. Models are important when it comes to managing an area as large as the backcountry of British Columbia.

“In some of the forecast areas, there actually aren’t a lot of direct observations of conditions and the models can provide an additional stream of data for forecasters to better understand what’s happening in the snowpack.”

On the social sciences side, his team is trying to better understand risk communication tools

“How well do hobbyists understand the newsletter? How do they use these tools to make decisions? How and where can we improve it? Even the best avalanche forecasts in the world will be of limited value if users cannot understand or apply them.

He says they can’t predict the exact conditions in real time on specific slopes or bowls – you would need local knowledge for that. But the models are useful at a more regional level.

“General conditions at alpine, treeline and below. That’s the kind of level of detail we try to provide.

He notes that one of the changes Avalanche Canada has implemented is to adjust forecast limits based on conditions. In other words, Valemount could be in one forecast area one week and in another forecast area a different week if its conditions change.

Haegeli says there is always room for improvement in communicating avalanche risk.

“There are always so many factors that come together in these accidents, but there is certainly room for improvement in trying to potentially communicate avalanche risk and consequences in a more tangible way,” he said. he declares.

Some of their research has shown that people are quite good at answering survey questions about the meaning of different terms in the avalanche bulletin, but when put in a situation where they have to assess different slopes or choose a trip under certain conditions, they sometimes fail to apply this knowledge.

“The important step for recreation enthusiasts to take is how they relate that information to what they’re going to do in the field,” he says. “It’s a tough step to take.”

the avalanche

The avalanche was triggered remotely near the edge of the bowl at one point. The runners were about 20 m from the bottom of the track. Avalanche Canada did not report whether they were moving or stopping at the time. The avalanche unfolded on a layer of facets near the base of the snowpack, which had been deposited in November, with a crown thickness between 80 and 120 cm.

On Saturday, Avalanche Canada said conditions were particularly bad around Valemount and that it had received numerous reports of large human-triggered and remote avalanches throughout the day, and warned people to choose terrain safer.

“Remotely triggered avalanches are a strong sign of an unstable snowpack,” Avalanche Canada said. “It’s a dangerous snowpack and it seems to be particularly volatile in this region right now.”

The problem of weak buried layers has been a major problem this season, they say. Forecasters compared the potential for avalanches this year to that of 2003, when 29 people died across Canada. Many of the human-triggered avalanches that occurred in the week prior to the killer avalanche were very large avalanches at the upper treeline/lower alpine, both over a surface hoar layer 50 cm d thickness in the middle of the snowpack and on weak facets at the bottom of the snowpack.

“Avalanches like these are more likely to trigger on steep, shallow, previously undisturbed slopes,” Avalanche Canada reported last Thursday.

On Monday, avalanche conditions were extensive at tree line and above in the McBride, Valemount and Blue River areas (see map). Conditions were expected to deteriorate further in McBride constituency areas this week.

This is the third avalanche-related death this month in the province. On January 9, two off-duty police officers were caught in an avalanche near Kaslo. One died that day while the other died on Saturday after being hospitalized with serious injuries.

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