Key facts
- A wildfire in southwest France generated a pyrocumulonimbus cloud, a rare phenomenon that produced lightning.
A wildfire in southwest France became so intense it created its own thunderstorm, generating lightning that sparked new fires beyond the original blaze. This rare pyrocumulonimbus phenomenon also produced erratic winds, complicating firefighting efforts.
This event highlights the escalating impact of climate change, where extreme weather conditions are enabling wildfires to generate their own destructive weather systems, posing new and unpredictable challenges for firefighting and community safety.
A wildfire in southwest France has grown so intense that its smoke column transformed into a thunderstorm, generating lightning that ignited new fires beyond the original blaze. French officials reported the phenomenon, known as a pyrocumulonimbus (pyroCb), which is rare in Europe and more commonly documented in North America and Australia.
The blaze, which erupted near Saumos on July 22, has burned over 420 square kilometers (162 square miles) of forests and scrubland, damaged or destroyed more than 240 homes, and forced 220,000 people to evacuate in the Gironde region.
On Friday evening, the departmental fire and rescue service confirmed the generation of a pyrocumulonimbus. This electrified black thundercloud, formed by intense heat and smoke surging upward, can create its own weather system. It produces violent, erratic winds capable of driving flames in new directions and can also spawn fire whirls. This creates a feedback loop that makes the fire harder to predict and control, potentially trapping firefighters and forcing them to retreat.
While pyroCb events have been recorded in Europe, such as in Portugal in 2017, France has now joined the list. The continent is experiencing faster warming than the global average, leading to more frequent and severe heat waves and droughts, which provide fuel for extreme fires. Scientists are still gathering data to establish trends, with projects like ROSETTA aiming to improve understanding of these events.