Overview

• Dozens of photos posted Saturday morning showed a plume-like opening in a cloud layer across parts of Provence.
• Independent meteorologist Paul Marquis and local weather pages identified the feature as a cavum, also known as a trou de virga, a term recognized by the World Meteorological Organization.
• Météo-France explains the process as ice crystals triggering rapid evaporation of surrounding droplets, sometimes initiated by brief pressure and temperature changes from a passing aircraft.
• Reports came from areas around Avignon, Aix-en-Provence, Marseille, Cavaillon, Salon-de-Provence, Arles, Forcalquier and Digne-les-Bains, with additional sightings in nearby departments.
• A witness in Rognes placed the start near 10:00 and estimated the phenomenon lasted about 20 minutes, while experts emphasized it is rare for the region and not dangerous despite UFO comparisons online.