VANCOUVER—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, said the phenomenon is known as a pyrocumulonimbus firestorm and has been tracked this year in British Columbia, Saskatchewan Alberta, 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 USA and Canada.” An abundance of fuel, heat and wind create …