Reference:

"Wildfires in the U.S. and Canada have become so intense that they are producing" "pyrocumulonimbus" "clouds, which can generate tornadoes and ignite additional fires."

Pyrocumulonimbus cloud:

They are formed by extremely severe wildfires or volcanic eruptions. Recently, due to the increase in global temperature, the incidents of forest fires have seen a significant increase, the main reason for which is being attributed to pyrocumulonimbus clouds.

PROCESS:

The intense heat from the fire rises while heating the surrounding air, which collides with the cold air above at high speed to form a lightning conductor. The electrical conductors once again cause forest fires in the forest. 

• These pyrocumulonimbus clouds can reach heights of up to 50,000 feet and produce their own storms.
• They can ignite new wildfires away from the main fire and cause strong winds, which cause the fire to spread rapidly.

A few related points:

Before 2023, about 102 pyrocumulonimbus clouds were recorded globally per year, of which 50 were in Canada. But in 2023, 140 pyrocumulonimbus clouds were recorded in Canada alone.