A combination of intense heat and drought conditions is causing wildfires in Western Canada to generate their own weather systems, experts say.
Michael Fromm, a meteorologist with the United States Naval Research Laboratory, based in Washington, D.C., said the phenomenon is known as a pyrocumulonimbus firestorm and has been tracked this year in British Columbia, Alberta, Saskatchewan, Manitoba and Ontario.
Scientists have been tracking the storms since May. The first one was seen this season in Manitoba, Fromm said in an interview Monday.
The Village of Lytton in B.C. saw firestorms on two successive days in late June, he said.
“It was probably the single largest pyrocumulonimbus storm of the year so far,” he added.
“In fact, we’re still tracking the smoke plume from that storm as it’s travelling around the world and it’s about to kind of come full circle back over the U.S. and Canada.”
‘Perfect’ firestorm conditions in B.C.
An abundance of fuel, heat and wind create perfect conditions for the firestorms.
Lytton hit a Canadian temperature record of 49.6 C the day before a wildfire erupted there on June 30, destroying much of the community.
“When you get all those three things together, you get the perfect triple that we call fire weather,” Fromm said. “So, hot, dry and windy.”
Simon Donner, a climate scientist from Vancouver’s University of British Columbia’s geography department, said the storms also generate lightning that causes more fires.
“The fire creates the storm, and then the storm creates lightning, which can cause more fires,” he said.
“That runaway feedback is the dangerous part.”
Above-average temperatures for many parts of B.C. aren’t expected to ease soon. Environment Canada said there is no hint of showers until at least the weekend for some southern regions that have been hit hard by wildfires.
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