Official report shows Fort McMurray Fire created lightning-started fires 26 miles away
As the wildfire season slows in the western United States and Canada we have had a chance to look back on some of the more significant blazes. One of the largest in recent years, if not THE largest, was in 2016 in Alberta, Canada, the 589,552-hectare (1.4 million-acre) Horse River Fire that generally became known as the Fort McMurray Fire. It burst into the headlines when it burned into Fort McMurray destroying 2,400 structures and forcing 80,000 residents to evacuate for about a month.
Firefighters talk about “extreme fire behavior”, but this fire took it to a different level. For example, according to the report released in June, on May 4 high spread rates and downwind spotting drove the fire 40-45 kilometres (26-28 miles) to the southeast by the next morning. Convection column heights on the afternoon of May 4 reached 12.5 kilometres (41,000 feet or 7.8 miles) and lightning from the pyrocumulonimbus cloud atop the column started a number of new wildfires 40 kilometres (26 miles) ahead of the main wildfire front.
Yes, lightning from the smoke column and clouds created by it started multiple new fires 26 miles downwind.
As climate change extends the length of wildfire seasons, Alberta is no exception. Since 1994 50 percent of the wildfire acres (or hectares) burned in the province have occurred in May. And right on schedule, two fires started at about the same time on May 1, 2016, one within the city limits of Fort McMurray and another west of the city.