Over the weekend, beachgoers in Portugal found themselves seeking shelter as a rare atmospheric event known as a “tsunami roll” swept across the coastline. This phenomenon was characterized by an impressive wave of dark clouds that developed over the water, creating an awe-inspiring yet unsettling sight.
Footage from Praia de Buarcos captured the moment when the sizeable roll cloud moved in, blocking sunlight and generating strong winds. One beachgoer described the experience on social media, comparing the sight to something out of a cinematic disaster film.
These rolling clouds, which appeared as temperatures soared above 107 degrees Fahrenheit, are known as arcus clouds. According to meteorological experts, such clouds arise when the cool air from a thunderstorm front pushes outward, leading to the condensation of warm, humid air that starts spinning horizontally.
Despite causing a stir among the crowd, the roll cloud did not signal an impending tsunami, but rather a natural weather occurrence. Following the initial spectacle, the region witnessed heavy rain, thunderstorms, and even hail. The roll cloud reportedly extended for over 90 miles along the Portuguese coast, with sightings from Vila do Conde to Figueira da Foz.
This summer, Portugal has been grappling with extreme heat, which has contributed to various weather phenomena. While the appearance of the roll cloud may have sparked panic, it also serves as a remarkable reminder of the dynamic nature of our atmosphere and the fascinating meteorological phenomena that can occur during extreme temperature events.