What is Spain’s DANA weather phenomenon and is climate change making it worse?

A DANA caused the deadly flooding in Valencia in 2024 which killed 200 people. A storm in eastern Spain has killed five people and left cars and streets submerged in water, and the DANA weather system is behind it. Storm Adam dumped 700 litres of rain per square metre in just 24 hours in some areas of the Valencia region. Floodwaters swept away parked cars, submerged roads and cut off residents, some of whom had to be airlifted to safety by emergency crews. The coastal resort of Oliva was one of the areas worst hit by Sunday night’s storms. A 79-year-old woman was found dead in her home, while a man suffered a fatal heart attack at a local campsite. The third victim was a man who drowned while swimming at a beach in Sagunto. Firefighters in neighbouring Catalonia also reported the death of a woman who fell into a rain-swollen stream. Storm Adam is reminiscent of the sudden downpours that devastated Valencia in 2024, when some areas saw a year’s worth of rain in just 24 hours. 200 people lost their lives, making it one of the worst flood-related disasters in Europe since the late-1960s and the worst in Spain for many decades. The government came under heavy criticism for the lack of warnings to the public about what was to come. Thankfully they appear to have learnt their lesson: warnings were sent to mobile phones before Storm Adam hit, urging people to avoid travelling, stay away from rivers and ravines, and seek shelter on higher ground or on the upper floors of buildings. The 2024 storm introduced many Europeans to a weather phenomenon that often hits Spain: DANA. What is it and is it becoming more deadly as the climate warms up? What is a DANA? DANA stands for ‘Depresión Aislada en Niveles Altos’. It’s not easy to translate into English but it essentially means periods of heavy rain, stormy weather and a sudden drop in temperatures. The bigger the temperature difference, the bigger the storm. This is why the worst DANAs are usually at the end of summer in September and October, and are more likely to happen in parts of southern and eastern Spain. Put simply a DANA is a very intense wind current that forms when it breaks away from a polar jet, a sort of pocket of cold air surrounded by warmer air that can move around and cause extreme weather. It’s the meeting of hot and cold air fronts causing extreme weather. Southeastern Spain is particularly vulnerable to DANAs because it’s where the Atlantic and Mediterranean meet, meaning that cold air fronts can meet warm air fronts at certain times of year. It’s also an area where mountains favour the formation of storm clouds and therefore rainfall. DANA is increasingly used in everyday language in Spain Some Spanish people now use the term DANA to refer to a big storm, but this hasn’t always been the case. For many years Spaniards have used the phrase ‘gota fría’, literally meaning ‘cold drop’, The Local Spain explains. But as technology has advanced, and it has become easier to predict and understand the weather, meteorologists say that DANA is a more useful term because it’s more specific. On its website, Spain’s meteorological agency Aemet explains that: “The term gota frìa is a relatively old concept and has been superseded over the years. New ways of understanding tropospheric processes and new observational tools have made us revise and redefine the ideas linked to these isolated pockets of cold air at higher levels. “We believe that the concept of DANA, which we associate with the Anglo-Saxon term ‘cut-off low’, is more accurate and realistic than that of gota fría. As the concept of a gota fría is not very precise and incomplete, it is understood that it should be replaced by a more modern one.” Is climate change making DANAs worse? The Valencia floods in 2024 made worldwide news, with many shocked by the scale of loss and devastation in a wealthy European country. Much analysis followed, with climate scientists asking what role global warming played. It was confirmed that a DANA was to blame and that global warming very likely made it worse. “No doubt about it, these explosive downpours were intensified by climate change,” Dr Friederike Otto, lead of World Weather Attribution at the Centre for Environmental Policy, Imperial College London, said in 2024. The floods were caused by a ‘cut-off low pressure storm system’ that had migrated from an unusually wavy, stalled jet stream. This system then got stuck over the region, pouring down a year’s worth of rain in eight hours. Unusually warm sea surface temperatures, made much more likely by human-caused climate change, and our warming atmosphere, however, directly impact how much rain these storms can hold. The ground in many parts of eastern and southern Spain had also been left less able to effectively absorb rainwater following severe drought. A rapid partial analysis done by Dr Otto’s group of international scientists suggested that human-caused climate change made Spain’s rainfall around 12 per cent heavier. It also found that the weather event the region experienced was twice as likely. Though it isn’t a full, detailed attribution study, they said climate change is the most likely explanation for the extreme downpours. “With every fraction of a degree of fossil fuel warming, the atmosphere can hold more moisture, leading to heavier bursts of rainfall. These deadly floods are yet another reminder of how dangerous climate change has already become at just 1.3°C of warming,” Otto adds.