A visually striking phenomenon, known as a “fog waterfall”, was visible above the Barcelona skyline during sunrise on April 27.
Alfons Puertas Castro, a member of the Fabra Observatory team of meteorological observers, produced timelapse footage of the clouds after he noticed them sweeping in over the city.
This is not an unusual occurrence in the Catalan city, according to Puertas Castro.
When contacted by Storyful, he explained, “The ‘fog waterfall’ phenomenon occurs when cold and humid air from inland enters the city through the bed of the Besòs River.”
He added, “This cold air, weighing more than the city’s temperature, flows towards lower altitudes like a river of clouds, seeking the sea. It is a more frequent phenomenon in winter and spring after a calm night.” Credit: Alfons Puertas Castro via Storyful