Nighttime Once Brought Respite to Firefighters, But Not Anymore, Study Finds

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West Kelowna Fire Chief Jason Brolund says he’s seen thick smoke turn from day to night in his years as a firefighter, but the opposite happened when a fast-moving fire swept through his community one night last August.

“The orange color of the flames reflecting off the smoke and clouds above us lit up the night,” he says.

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“We saw our most ferocious fire behavior take place well after dark, in the early morning hours. (That was) when we had the worst battles,” Brolund says of the McDougall Creek Fire, which ultimately destroyed or damaged nearly 200 properties.

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Brolund’s experience echoes the findings of a new Canadian study, which found that drought is the driving force behind wildfires that burn overnight.

Dry fuels promote extreme fire behavior and growth at night, the paper says, although rising temperatures are also eroding the “climatological barrier” that has typically limited nighttime burning.

The days of skeleton crews on night patrols are long gone, Brolund says. It marks a change in the belief that darkness usually means calmer fire conditions.

“That’s what they taught us in fire school about 25 years ago,” Brolund says.

“But that’s not what’s happening now.”

Mike Flannigan, one of the study’s co-authors in British Columbia, says uncovering the role of drought led them to further demonstrate that daytime conditions can be used to predict how a fire will burn at night, information that could be crucial to efforts. of extinction.

“We have fire growth models and they manage the day very well most of the time, and that’s usually the most important part. But at night they don’t do well,” she says.

“Any kind of information about how active a fire will be overnight is really critical…especially if a fire is approaching a city, like West Kelowna was last year,” Flannigan says.

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Wildland firefighters work at night in such situations, when flames threaten people and infrastructure, Flannigan says. It’s not a standard policy for most fires, and traditionally, the nightly reprieve is “almost taken for granted,” she says.

The study, published Wednesday in the peer-reviewed journal Nature, suggests this is an increasingly risky bet as climate models predict summers will be hotter and drier, conditions Flannigan describes as a “barrel.” of gunpowder” for forest fires.

Canada’s drought bulletin shows pockets of “exceptional” and “extreme” drought in central British Columbia and southern Alberta, while drought conditions in swaths of both provinces were rated as moderate to severe at the time of the February 29 update.

BC has yet to update its drought information portal this year, but the final November update shows much of northern BC is in severe drought and snow cover across the province has been lower than normal throughout the year. winter.

“If I were thinking about this summer, I would be worried about them burning overnight,” says Flannigan, a professor at Thompson Rivers University in Kamloops and research chair in predictive services, emergency management and fire sciences at BC.

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The study used wildfire records and satellite data to examine more than 23,500 wildfires in North America between 2017 and 2020. The researchers identified 1,095 nighttime fires associated with 340 wildfires and found that the vast majority spanned at least 10 square kilometers.

The causes were dryness and the availability of forest fuels, such as grasses, fallen leaves, twigs and branches, according to the document.

The research, led by Kaiwei Luo of the University of Alberta, also found that nighttime burning often occurred within two days of ignition.

This is important, Flannigan says, because it’s a crucial time to marshal firefighting resources with the goal of containing flames before they spread.

Brolund says fighting wildfires at night is a “nightmare” scenario.

The darkness makes visibility and information available to crews difficult. It is more difficult to operate heavy equipment and air support is limited, she says.

It’s also harder to alert the public to the danger, he adds.

“These things now could happen at any time,” Brolund says of the nighttime outbreaks.

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“We have to be able to respond to these fires 24 hours a day.”

The researchers also developed models to explore whether nighttime burning could be predicted, a potentially powerful tool, and found that daytime conditions set the stage for what happens at night.

“On that day, you can say, ‘There’s a high chance you’ll burn all night,’ and prepare accordingly,” Flannigan says of the new model.

He works closely with the BC Wildfire Service’s predictive services arm and says researchers will provide their model with hopes of testing it this summer.

“Not every year is going to be bad fire years. Some years will be colder, others wetter,” she says.

On average, summers will be hotter and drier, forcing firefighting at night, he says.

Brolund says his department had already changed its approach to staffing, assigning an equal or greater number of staff to work at night last summer.

The McDougall Creek Fire set a new standard for wildfire operations, he says.

“You know, it happened here, and I don’t think it’s enough to say it’s a once-in-a-career thing that will never happen again,” he says. “Unfortunately, it is likely to happen again and it is the bar we must prepare for.”

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