France's southwest wildfires trigger rare pyrocumulonimbus, creating its own weather for first time

Dense smoke clouds from the wildfires southeast of the French seaside resort of Lacanau-Ocean darken the sky. Source: Jan Athmann/dpa

As if the wildfires in France were not destructive enough, an extraordinary phenomenon is now worsening the situation: a firestorm that even produces lightning. Experts say the "force of nature is out of control."

A firestorm generated by wildfires, producing a glowing hot cloud with its own weather, has occurred for the first time ever in France, according to the fire department. The phenomenon—called Pyrocumulonimbus—emerged during the devastating wildfires in the southwest of the country.

What Is a Pyrocumulonimbus Cloud?

The cloud, also known as Cumulonimbus flammagenitus, forms when air near the ground heats up so intensely that it rises rapidly along with smoke, water vapor, and ash—often several kilometers high into the stratosphere.

There, the mixture meets cooler air masses and creates its own weather system with strong winds that further fuel the fire. Often, lightning even strikes from the cloud to the ground, accompanied by a rumbling sound.

These "fire-breathing dragons," as NASA calls them, have so far been observed mainly during volcanic eruptions and massive fires in Australia and Canada. While the phenomenon occurs repeatedly in those regions, it is "unprecedented" in France, says fire department spokesperson Eric Brocardi to the AFP news agency.

Why It Is So Dangerous

Extinguishing or bringing the firestorm under control is usually not possible, among other reasons because the winds constantly change direction, Brocardi explains.

"The result is that it spreads in all directions and forms multiple fire fronts, making the situation completely unpredictable."

The huge smoke clouds make the work for the fire department even more dangerous. Source: AP Photo/Emma Da Silva

Only Two Ways Out

According to Brocardi, there are then only two possible outcomes:

• Rain arrives — "but it would have to pour heavily for three days."
• Steer the fire — "we find a way to steer the fire to a place where it goes out on its own—for example, at the sea."

Firefighters Forced to Retreat

With the fire cloud in southwestern France, the firefighters could only retreat, Brocardi explains.

"We must acknowledge that this force of nature is beyond our control. It is a war-like scenario where we are constantly under attack and everyone must take cover."

Then only "stoicism" helps, Brocardi adds. Besides direct firefighting, the fire department can still do a great deal—such as defending strategically important points and bringing animals to safety from the flames.

AFP/rc