What this weekend's heat means for Alberta's wildfires
‘It's going to make dry things even drier,’ fire scientist said
After a brief break in the summer-like weather, the heat is building once again in Alberta.
A ridge is building in the upper levels of the atmosphere. This will keep Alberta and much of B.C. hot and dry through the weekend and into the start of next week.
"The most intense heat for northern Alberta looks like it's probably Sunday into Monday," said Terri Lang, meteorologist with Environment and Climate Change Canada.
"We may see some record-breaking temperatures, but as we get further out in May, the [old] records get higher. So we'll have to just wait and see."
This latest round of heat comes as the wildfire season in the province is off to a busy start.
Though many regions in central Alberta saw cooler temperatures and rainfall this week, northern stretches of the province were left relatively dry.
"[Getting] back into the heat and low humidities — not a good scenario coming up for this weekend unfortunately," Lang said.
Another important weather factor to watch is the wind. While we usually don't see strong winds with this particular weather pattern, it could still be a factor through the weekend.
"It is spring on the Prairies, so there always seems to be wind. And of course these fires themselves create their own weather and their own winds," she said.
The upper ridge looks to break down through next week which will also impact our winds. Storm systems are more common after these ridges, meaning that fires can move and grow.
Dry conditions and fire
This week's lull in the weather has lowered the fire risk for much of the province, but forecasts show that risk will jump back to extreme levels by Sunday with the incoming heat.
Watch: How wildfires can create their own catastrophic weather events
"It's going to make dry things even drier," said Mike Flannigan, the research chair for Predictive Services, Emergency Management and Fire Science at Thompson Rivers University, in Kamloops, B.C.
According to Flannigan, though the top levels of vegetation may become wet, the deeper vegetation below the surface can remain dry.
That is what we are seeing in much of Alberta, as drought conditions have continued.
"The top of the forest floor, the needles, the leaves, the grass, they can dry out in a day. One hot, dry, windy day," Flannigan said.
And although we don't expect a lot of lightning this weekend, the thunderstorm activity in the province earlier this week could impact fire activity.
When lightning strikes, it can ignite fuel below the surface of the ground. Those fires can smoulder until the top level of vegetation is dry enough to support an active fire.
"We call them holdover fires, because they're holding over, waiting," said Flannigan.
"So the lightning we see today may not cause wildfires today, but maybe tomorrow or the day after or the day after that."
What to expect going forward
The forecast for the weekend and next week is a dangerous one for wildfires. Flannigan said flare ups could happen across Western Canada.
"My concern now is not just Alberta, but northeastern B.C., parts of northern Saskatchewan and even southern parts of Northwest Territories," he said.
Although this May has been a notable one for fire, Flannigan said that with climate change, it's not entirely surprising.
He says that fire seasons have been early and busy in Alberta especially in 2011, 2016, 2019 and now in 2023.
"Every three to five years we're getting hit in May in Alberta," he said.
According to Flannigan, climate change is affecting the length and severity of seasons, in some regions much faster than expected.
"I do expect we'll continue to have years where it's going to be quiet, it's going to be cooler and wetter than normal and fire won't be a problem, but those are going to become rarer," he said.
"The average year is going to be fairly active and so we have to learn to live with fire and smoke."
The rest of this season
The busy start to this wildfire season is not necessarily indicative of the season to come.
Flannigan said that ongoing drought is a concern heading into the summer, but it's highly dependent on how much rain Alberta gets, and when it arrives.
"What happens in the early season isn't correlated or related to what happens later in the season," he said.
"The pattern could change and we could see a lot of rain and it really depends on the day-to-day weather."
One aggravating factor for this summer is the high likelihood of a moderate to strong El Nino developing.
El Nino refers to the periodic warming of the surface waters in the eastern Pacific ocean — a phenomenon that affects weather patterns around the world.
"That could play a role in our fire season, especially in western areas like Alberta and B.C.," said Flannigan.
During moderate to strong El Nino years, Alberta and B.C. often experience warmer than normal conditions, and in some cases, dry conditions as well.
If that happens, Flannigan says both provinces could have a very active year for fires.
ABOUT THE AUTHOR
