Night no longer offers reprieve
Drought conditions allow flames to keep burning after dark
Jason Brolund, the fire chief in West Kelowna, B.C., says he’s seen thick smoke turn day to night in his years as a firefighter, but the opposite happened when a fast-moving blaze tore through his community one night last August.
“The orange of the flames reflecting off the smoke and cloud above us lit up the night,” he says.
“We saw our fiercest fire behaviour taking place well after dark, in the early morning hours. (That’s) when we had the worst battles,” Brolund says of the McDougall Creek fire, which ultimately destroyed or damaged nearly 200 properties.
Brolund’s experience echoes the findings of a new Canadian study, which found drought is the driving force behind wildfires burning overnight.
Bone-dry fuels promote extreme fire behaviour and growth at night, the paper says, though warming temperatures are also eroding the “climatological barrier” that has typically limited overnight burning.
The days of a skeleton crew on night patrol are gone, Brolund says. It marks a shift from the belief that darkness typically means calmer fire conditions.
“That’s what they taught us in fire school like 25 years ago,” Brolund says. “But that is not what happens now.”
Mike Flannigan, one of the study’s co-authors in British Columbia, says uncovering the role of drought led them to further show that daytime conditions can be used to predict how a fire will burn overnight, information that could be crucial for firefighting efforts.
“We have fire growth models, and they handle the day really well most of the time, and that’s usually the most important part. But they don’t really do well at night,” he says.
The study, published Wednesday in the peer-reviewed journal Nature, suggests that is an increasingly risky bet as climate models predict summers will get hotter and drier. The study used wildfire records and satellite data to examine more than 23,500 blazes across North America from 2017 to 2020.