Large storm areas, called mesoscale convective systems, can be seen entering the camera’s field of view from the east and moving westwards to the Atlantic Ocean. Such systems are driven by so-called African easterly waves, which are disturbances that form in the general easterly airflow over tropical northern Africa and spread westward.

They force an upward air movement that triggers widespread thunderstorm activity along the wave. These systems may propagate westward across the tropical and subtropical North Atlantic and reach the Caribbean Sea and western North Atlantic. Some African easterly waves become hurricanes.

Monitoring these thunderstorm systems is important as they frequently cross the main aviation routes between Europe and South America. Some more localised coastal storms and afternoon thunderstorms over the landmass of Africa are also visible in the animation. Sun glint can be seen moving from east to west every afternoon.

This animation, zooming in on western Africa, was made using five days’ worth of data from the Meteosat Third Generation Lightning Imager’s west camera, from 00:00 UTC 4 June to 23:59 UTC 8 June 2023. It was made from raw preliminary data and is not for operational use.