Forest fire in France creates the country's first pyrocumulus with lightning

A forest fire in southwestern France became so powerful that its column of smoke turned into a thunderstorm, generating lightning that struck the ground and ignited new fires outside the original perimeter, French officials said, according to UNN citing AP.

Details

In other words, this means the flames were not just driven by the weather. They were creating their own. The thundercloud also produced strong, unpredictable winds capable of driving the flames in new directions.

This phenomenon, called a pyrocumulonimbus, or pyrocumulus, is rare in Europe and is most often documented in North America and Australia, where it is observed only over some of the largest fires. France's National Federation of Firefighters said it had never before recorded such a phenomenon in the country.

The fire broke out near Saumos on July 22 and has since destroyed more than 420 square kilometers of forests and scrubland, damaged or destroyed over 240 homes, and forced 220,000 people to evacuate in Gironde.

At around 6:20 p.m. on Friday, two days after the fire started, the department's fire and rescue service reported the formation of a pyrocumulonimbus. The cloud weakened overnight due to increased humidity, then formed again several times.

Repeatedly, heat and smoke rose upward, forming a huge black thundercloud, electrified and lit from within.

"Imagine a flame so large and hot that the smoke rising from it turns into a thundercloud," said Theodore M. Giannaros, a fire meteorologist at the National Observatory of Athens.

"This is a pyrocumulonimbus — a thundercloud born from the intense heat created by a forest fire," he said.

For this, a large fire alone is not enough. As Giannaros said, there is no specific temperature at which it forms; a conducive atmosphere for dry thunderstorms is needed — very hot, very dry air near the ground, with cooler and moister air above. Hot air, saturated with smoke and moisture, rises rapidly from the flames. As it rises and cools, water vapor condenses around ash particles. Above the freezing level, droplets turn into ice crystals, whose collisions separate electrical charges, as in a regular thunderstorm. This is followed by lightning and new destruction. The rising air draws powerful winds toward the fire, while downdrafts send gusts back to the surface.

These changes can alter the direction of the flames, split them into multiple fronts, or channel them into a new course. "It's a feedback loop, not a one-way effect," said Giannaros. "Once the cloud forms, it becomes its own weather system, hovering over the fire's epicenter and complicating its prediction."

These systems can also create vortex columns of flame — typically a fire whirl, which Giannaros describes as a dust devil made of fire and heat, rather than dust.

Until now, pyrocumulus clouds have essentially been a phenomenon characteristic of Australia and North America. In Canada alone, a record number of pyrocumulus clouds — 142 — were recorded in 2023.

In Europe, pyrocumulus clouds are rare.

In Portugal, one such cloud was recorded during the deadly 2017 fire season. Now France has joined this list.

The continent is warming faster than any other on Earth — about twice as fast as the global average since the 1980s, according to data from the EU's Copernicus Climate Change Service and the World Meteorological Organization — with heatwaves becoming more frequent and intense, and drought spreading southward, turning forests into fuel.

Hotter and drier conditions provide more opportunities for extreme fires to occur, Giannaros said, but scientists still lack long-term data to establish a trend. The European research project ROSETTA aims to fill this gap.

The most common mistake, according to him, is that the cloud is just a side effect. While it hangs over the flame, it helps determine where the fire will spread next.

Macron called the fight against forest fires "the most difficult since World War II"

French President Emmanuel Macron said that France is experiencing the most difficult situation since World War II.

The fire in the southwestern Landes region of France has been "contained," President Emmanuel Macron said on the evening of July 27, according to CNN affiliate BFMTV.

"The fire is contained, which is good news for the Landes," BFMTV quotes Macron as saying during his visit to Gironde, a neighboring region that has been hardest hit by the forest fires. The fires in the Landes, which started on Thursday, have covered more than 3,600 hectares and destroyed 198 buildings.

In Gironde, the region that includes Bordeaux, Macron said the fires have been "stabilized."

"But they remain intense, and we must be extremely cautious in the coming hours and days," he added.

During his visit to Gironde, Macron visited the Departmental Operational Fire and Rescue Center (CODIS) in Bordeaux, where forest fire specialists briefed him on the situation.

"We must understand that we are facing an absolutely unprecedented forest fire," he said. "The situation we are dealing with today is the most serious we have ever recorded, the most difficult since World War II. More than 160,000 hectares have already burned, and the season is far from over."