Experts say Sask. wildfires could remain ablaze until snowfall

CBC

19 hours ago

Wildfires continue to rage in northern Saskatchewan as the province faces its worst fire season in more than a decade.
Increasingly warmer-than-average spring temperatures, prolonged periods without rain and strong gusting winds have only exacerbated the situation.
Low on power or data? Use CBC Lite for the latest on wildfires
One thing is clear: no matter how many firefighters are sent to control the growing fires, it's up to mother nature to put out the flames.
Dry leaves, twigs and pine needles on forest floors act as a base for wildfires to ignite, and northern Saskatchewan has experienced a lack of moisture this year.
Environment and Climate Change Canada (ECCC) confirmed La Ronge had its second driest spring in 60 years.
Fire specialists that CBC spoke to said rainfall is the only long-term solution.
How much rainfall is needed?
A low-pressure weather system rolled into the province's north last week, finally bringing some moisture to the area. Some parts got up to 40 mm of rain.
But fire specialists warn it's nowhere near enough.
"You're almost at 1,000,000 hectares, which is about 40 times the size of Saskatoon," Mike Flannigan, a professor of wildland fire at Thompson Rivers University, told CBC.
"It's a huge area that's on fire and it's producing lots of smoke. Every time you get a couple dry days and the wind picks up, you're going to see these fires grow unless we get two weeks of rain, or 100-plus millimetres."
If the province did get 100 mm of rain, Flannigan said many of the fires would be put out, but hotspots would still be burning in deeper organic material and on logs in the forest.
June is typically Saskatchewan's mini "monsoon" season, where upper lows come through and drop lots of rain at once. Flannigan said at least three of those rainfalls would be needed during the month to provide any tangible relief.
Thunderstorms, wind can lead to spread
Although moisture is needed in the province, the risk of lightning that comes with showers could make things worse.
Lightning strikes can spread existing fires or create new ones.
"It was a warm dry spring in much of the Prairie provinces and we got some human-caused ignitions. Now we're getting lightning-caused ignitions, it's been windy and the fires are growing," Flannigan said.
"The warmer we get, the more lightning we expect."
Certain wildfires can even produce a thunderstorm, called a pyrocumulonimbus. Clouds are formed when air is drawn into a smoke plume, becoming more humid, unstable and favourable for the creation of thunderstorms.
"We've seen a number of them in Manitoba and Saskatchewan this fire season, more than most years," Flannigan said. "That's a sign that fires are getting more intense and generating these thunderstorms, which can also produce hail, rain [and] lightning."
Thunderstorms also bring strong, gusting winds, another factor that can make matters worse.
Strong winds can push fires faster than they'd normally grow, which makes them more difficult to suppress, and create a dryer atmosphere.
"Strong winds can help dry out things like grasses or your smaller twigs more quickly," Liam Bouchard, a fire weather specialist with the Canadian Forest Service, told CBC.
The only positive to wind gusts is they can sometimes push smoke out of communities.
Experts say fires may burn until snowfall
Experts warn the rest of the summer may be hot and dry, conditions favourable for the continuation of wildfires.
"[If] these heat waves come back, there is potential for very warm temperatures as we are approaching the middle of summer," Bouchard said.
High temperatures and a lack of rain could mean some fires may not be fully extinguished all season.
"I'm afraid that some of these fires will burn through the summer into fall," Flannigan said. "It'll be winter that puts out most of these fires. And in fact, sometimes fires can burn right through the winter."
The phenomenon is known as an overwintering fire, in which fires continue burning underground throughout the winter. Sometimes when fires are burning in deeper organic material, they can go underground and smolder very slowly. Even as snow falls on the forest floor, organic material continues smoldering underneath the surface.
"Spring 2026 comes, the snow melts, it warms up and the fire smolders back to the surface and starts spreading," Flannigan said. "So that's a concern."
If overwintering fires occur this year, the next wildfire season could be even worse.
The Saskatchewan Public Safety Agency (SPSA) confirmed to CBC that overwintering fires occurred in both 2017 and 2024.
"These fires are remediated very early in the spring, so they don't become a problem later," the SPSA said.
The agency said it's too early yet to say if overwintering fires will occur this year and that it depends on the amount of rainfall received as the summer goes on.
Hot summer ahead
With ECCC predicting above average temperatures, the chance of fires continuing remains a strong possibility.
"Much of Canada, particularly in the Prairies, experienced dry conditions," ECCC told CBC. "These conditions, in combination with the high likelihood of a warmer-than-normal summer, could increase the risk of wildfires in the coming months."
Projection maps from ECCC show that parts of northeastern Saskatchewan have a 90 to 100 per cent chance of seeing above-normal temperatures this summer. It's not clear by how many degrees temperatures will be above average.
"The scientific consensus right now is that warming temperatures and climate change are really priming the atmosphere, priming the forest for more fires in the future," Bouchard said.