Terrible images. At least 62 people died in devastating floods this Tuesday, October 29, in southeastern Spain, particularly in the Valencia region.
Entire communities are flooded by flash floods, roads have been transformed into veritable torrents and infrastructure has been devastated by the violence of the waters. The cause: a devastating storm called “V.”
Contrast with the soft Mediterranean air
The Valencian Community has been affected by a phenomenon that the Spanish call DANA, an acronym for “isolated depression at high levels.” This is a blocked depression in altitude, which is generally called a cold drop. A fairly classic situation for the season in the Iberian Peninsula.
Very cold air, at -75°C, at about 10,000 meters above sea level, meets much warmer and more humid air rising from the Mediterranean. With the water still warm, at more than 21°C off the coast of Valencia, the sea constitutes the fuel that feeds these particularly violent storms. It is the contrast between these air masses that causes the intensity of the observed rain.
In the satellite images we can see the footprint of the storm that forms a kind of triangle. Seen from above it looks like an oil stain that spreads with an almost fixed point – hence its name “V” –, located here in the Valencian Community.
Stationary storms
Here the intensity of the phenomenon is impressive. V-shaped storms are particularly devastating because they are stationary. Thus, the rains are constantly regenerated and are blocked inside the V.
“This type of organization is dangerous because it generates heavy rainfall that is constantly replenished in a restricted geographical area. In these storms it is common to observe serious flooding, landslides and sometimes even landslides. In a rugged area,” he writes the Keraunos Storm Observatory. .
“V-shaped storms are actually composed of a vast multicellular system that produces intense, nearly stationary precipitation,” he explains.
According to Keraunos, V-shaped storms can occur in France, but “they remain a rare phenomenon.”
Climate change
The Valencian Community and the Spanish Mediterranean coast in general periodically experience, in autumn, the meteorological phenomenon of the “cold drop”, an isolated depression at high altitude that causes sudden and extremely violent rains, sometimes for several days.
However, scientists warn that extreme weather events, such as heat waves and storms, are becoming more frequent, longer-lasting and intense due to climate change.
Source: BFM TV