How 'fire-generated thunderstorms' make wildfires more deadly

How 'fire-generated thunderstorms' make wildfires more deadlyImage source, ReutersImage caption, Described by scientists as a "fire-generated thunderstorm", pyrocumulonimbus clouds are created in the skies of FranceByHelen Willetts, Lead weather presenter and Olivia IrelandPublished27 July 2026, 12:04 BSTUpdated 2 minutes agoTens of thousands of people have been evacuated from Bordeaux's surrounding region of Gironde, as France continues to fight against wildfires being stoked by an unprecedented "pyrocumulonimbus" or fire clouds.Scientists sometimes describe these clouds as a fire-generated thunderstorm because the fire itself provides the energy needed to build the cloud.The huge amount of heat generated by wildfires makes the air above the fire rise rapidly, carrying smoke, ash and water vapour high into the atmosphere.As the air rises, it cools and the water vapour condenses into a cloud. If the fire is powerful enough and the atmosphere is unstable, that cloud can grow into a towering cumulonimbus - the same type of cloud associated with thunderstorms.Turbulent winds created by the fire clouds can send embers shooting off in all directions, making wildfires unpredictable and harder to fight. Lightning strikes can also spark more blazes.Live: French wildfire creates lightning storm as it threatens BordeauxThousands of acres burnt in wildfires in GirondePublished2 hours agoMore than 300,000 flee wildfires in France and SpainPublished1 day agoFrench firefighting authorities have blamed the phenomenon for the blazes near Bordeaux, adding that it had never before been seen in the country.Across Europe, the summer months have sweltered through intense, record-breaking heatwaves with minimal rain. This has meant regions have become dry and susceptible to wildfires which have been sparked in France, Spain and the UK.On Monday the Gironde prefecture said the situation remained "broadly stable" overnight.But efforts to tackle...