• More than 200 people have been killed in Spain, where a massive search and rescue operation is ongoing even as the rains continue. The Valencia region was worst affected, and some areas received more than the equivalent of a year’s amount of rainfall in the space of eight hours. 

• Spain’s meteorological and hydrological service, AEMET, has been issuing constant advisories and alerts throughout the week via the common alerting protocol.

• Climate scientists and meteorologists said the immediate cause of the flooding is called a cut-off lower pressure storm system that migrated from an unusually wavy and stalled jet stream. That system simply parked over the region and poured rain. This happens often enough that in Spain they call them DANA, the Spanish acronym for the system.

• The record-breaking rainfall and deadly flash floods that hit Spain this week underscore why saving lives as climate change turbocharges extreme weather must be a top priority, the World Meteorological Office (WMO) said. 

• The UN weather agency is highlighting the importance of early warning systems for all corners of the planet and reducing greenhouse gas emissions that cause climate change.

• Europe has been badly affected by floods this year. In mid-September, parts of Central Europe experienced very heavy rainfall, breaking local and national records.

• According to the Intergovernmental Panel on Climate Change (IPCC), extreme weather events causing highly impactful floods and droughts have become more likely and more severe due to anthropogenic climate change.

What is DANA?

• Catastrophic flash floods are caused by a destructive weather system in which cold and warm air meet and produce powerful rain clouds, a pattern believed to be growing more frequent due to climate change.

• The phenomenon is known locally as DANA, a Spanish acronym for high-altitude isolated depression (Depresión Aislada en Niveles Altos), and unlike common storms or squalls it can form independently of polar or subtropical jet streams.

• When cold air blows over warm Mediterranean waters it causes hotter air to rise quickly and form dense, water-laden clouds that can remain over the same area for many hours, raising their destructive potential. 

• DANA often occurs during the autumn season because the remaining warm surface heat from summer meets a sudden cold invasion aloft from the polar regions. This leads to what meteorologists used to call “a cut-off system” with low-pressure values that persist over a few days and rotating over the concerned region.

• Eastern and Southern Spain are particularly susceptible to the phenomenon due to its position between the Atlantic Ocean and the Mediterranean Sea. Warm, humid air masses and cold fronts meet in a region where mountains favour the formation of storm clouds and rainfall.

• Before the term DANA was coined in the early 2000s, any heavy rainfall in the autumn, characteristic of the Mediterranean climate, used to go by the popular name “gota fria” (cold drop) in Spain and parts of France. The term is still widely used colloquially.

• Its origin dates back to 1886 when German scientists introduced the idea of “kaltlufttropfen”, or cold air drop, to describe high altitude disturbance but without apparent reflection on the surface.

• The extreme weather event came after Spain battled with prolonged droughts in 2022 and 2023. Experts say that drought and flood cycles are increasing with climate change.

• A similar “cut-off” system in September 2023 (Storm Daniel) caused massive devastation in Greece and then moved on to Libya where it triggered the collapse of dams, causing massive loss of life.

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