Red-coloured altocumulus clouds during sunset announce the imminent arrival from the west of an Atlantic cold front. The Catalan aphorism is accurate: cel rogent, pluja o vent (= red sky, rain or wind).
The altocumulus clouds go ahead of the cold fronts. They spread like a white sheet in a sinusoidal pattern of regular and parallel curls that the perspective displays converging at a distant point. Altocumulus clouds are located above 4,000 meters high. In the sunset, when the sun is just hidden below the horizon to poor people on earth, the base of the altocumulus clouds receives the last rays of the sun. At that moment, the grandiose and ephemeral celestial spectacle lights up.
In the Bages district, the red sky in the sunset outcrops the tabular silhouettes of the south-west ranges.
The Atlantic fronts usually result in heavy rains in the western part of the Iberian Peninsula, in the Cantabrian Sea and in the western Pyrenees; on the other hand, they arrive almost exhausted or fully dry in Central Catalonia. The most noticeable weather results from cold fronts in Central Catalonia, even more along the drought period from 2021 to 2023, are the wind from the north-west, the drop of the temperature and a clear sky. If there is rain, it passes away quickly.
[photo Jordi Badia]