France firestorm phenomenon: monster clouds that spawn lightning and new blazes
The inferno ravaging southwest France creates rare fire clouds, never before recorded in the country
A wildfire in southwest France grew so powerful that its smoke column became a thunderstorm, generating lightning that struck the ground and ignited new fires beyond the original blaze, French officials said.
Put another way, that means the inferno was no longer simply being propelled by the weather. It was making its own. The thundercloud also produced violent, erratic winds capable of driving the flames in new directions.
The phenomenon, called a pyrocumulonimbus, or pyroCb, is rare in Europe and more commonly documented in North America and Australia, where it occurs only over some of the most extreme fires. France’s national firefighters federation said it had never before recorded one in the country.
The blaze erupted near Saumos on July 22 and has since burned more than 420 sq km (162 square miles) of forests and scrubland, damaged or destroyed more than 240 homes and forced 220,000 people to evacuate in Gironde.
At about 6.20pm on Friday, two days after the fire began, the departmental fire and rescue service said it had generated a pyrocumulonimbus. The cloud weakened overnight as humidity rose, then formed again several times.
Repeatedly, heat and smoke have surged upwards into a vast black thundercloud, electrified and lit from within.