Tens of thousands of people have been evacuated from Bordeaux’s surrounding region of Gironde, as France battles wildfires fuelled by an unprecedented phenomenon: pyrocumulonimbus, or ‘fire clouds’, which scientists describe as fire-generated thunderstorms. The massive heat from the fires causes air to rise rapidly, carrying smoke and water vapour high into the atmosphere. As it cools, the vapour condenses into clouds. If the fire is powerful enough and the atmosphere unstable, those clouds grow into towering cumulonimbus—the same type associated with thunderstorms.
Turbulent winds from these fire clouds send embers shooting in all directions, making the wildfires unpredictable and harder to fight. Lightning strikes can also spark more blazes. French firefighting authorities have blamed the phenomenon for the blazes near Bordeaux, adding that it had never before been seen in the country.
“Tens of thousands flee Bordeaux region as pyrocumulonimbus clouds create lightning storms and unpredictable wildfires.”
Across Europe, record-breaking heatwaves with minimal rain have left regions dry and susceptible to wildfires in France, Spain and the UK. On Monday, the Gironde prefecture said the situation remained ‘broadly stable’ overnight. But efforts to tackle the blaze could get further complicated with another heatwave forecast later this week, with highs of up to 40C predicted in France.
A senior official warned the wildfire in Gironde will likely burn ‘for many weeks’ and could take months to fully extinguish. While once seen as fairly rare events, a similar example was seen during the 2019-2020 Black Summer bushfires in Australia, which created extreme ‘firestorms’ that made their own weather. That event killed at least 33 people—including four firefighters—and more than 11…
Scientists have predicted that climate change is likely to increase the chances of such events.
