Animations from Europe's first Lightning Imager

The Lightning Imager’s western camera has a field of view covering the Atlantic Ocean, a small part of Africa and part of South America. This animation shows the Intertropical Convergence Zone, where clusters of tropical thunderstorms are slowly moving from the east (bottom right corner of the video) to the west (top right corner of the video). If the waters are warm enough from June to November, some of the larger storm clusters can develop into hurricanes affecting the Caribbean and the eastern United States. It is also clear from the animation that most of the lightning occurs over land and during the local afternoon and evening hours. Sun glint - reflection of the sun from the ocean and smaller bodies of water on the land - can be seen crossing the upper part of the field of view during the afternoon. The animation was made using five days’ worth of data from the MTG-I1 Lightning Imager’s west camera, from 00:00 UTC 2 June to 23:59 UTC 6 June 2023. It was made from raw preliminary data and is not for operational use.

The Lightning Imager’s northern camera faces Europe. The northernmost part of the field of view, that is, northern Scandinavia, never gets dark during the Northern Hemisphere summer. Local thunderstorms develop on a daily basis in southern Europe around the Mediterranean during the warmer part of the year. These storms form as the sun heats up the ground during the day and they dissipate relatively quickly after sunset. Some much larger and more persistent tropical storm systems can be seen in western Africa in the bottom left corner of the video. The rest of the Europe is mostly cloud-free as it was dominated by a large persistent high-pressure system when the data was collected. This animation was made using five days’ worth of data from the MTG-I1 Lightning Imager’s north camera, from 00:00 UTC 2 June to 23:59 UTC 6 June 2023. It was made from raw preliminary data and is not for operational use.

Very intense lightning activity occurs continuously in Africa. Local thunderstorms appear in the afternoon and disappear shortly after sunset, unless they develop into larger storm clusters, called mesoscale convective systems, which can be larger than 1,000km, and can stay active throughout the day and night. Most of the lightning activity in the animation is seen to the north of equator as its main trigger, the Intertropical Convergence Zone (ITCZ), moves northwards during the Northern Hemisphere summer. The direction of movement of clouds and storms in the southern part of the ITCZ is east to west, as opposed to the typical mid-latitude west to east airflow that can be seen in the storms in the upper right-hand corner. This animation was made using five days’ worth of data from the MTG-I1 Lightning Imager’s east camera, from 00:00 UTC 2 June to 23:59 UTC 6 June 2023. It was made from raw preliminary data and is not for operational use.

This Lightning Imager’s south camera observes the southern Atlantic Ocean, with the southernmost part of Africa visible in the bottom right. Much less lightning is visible in this animation than was observed by the instrument’s three other cameras because most of the field of view is ocean - most lightning occurs over land -  and it is the Southern Hemisphere’s winter - lightning mostly occurs during the warm season. The animation is mostly dark as the winter days are short. The small amount of lightning visible is mostly found in the rotating cloud spirals of mid-latitude cyclones, where warm tropical and cool polar air masses meet.  This animation was made using five days’ worth of data from the MTG-I1 Lightning Imager’s south camera, from 00:00 UTC 2 June to 23:59 UTC 6 June 2023. It was made from raw preliminary data and is not for operational use.

The northernmost part of the visible area, that is, northern Scandinavia, never gets dark during the Northern Hemisphere summer and polar day. Local thunderstorms appear during the afternoon in central and southern parts of Europe. These storms form as the sun heats up the ground during the day and dissipate relatively quickly after sunset. Some more persistent storm systems can be seen over the Mediterranean, staying active throughout the night. This animation, zooming in Europe, was made using four days’ worth of data from the MTG-I1 Lightning Imager’s north camera, from 00:00 UTC 8 June to 23:59 UTC 11 June 2023. It was made from raw preliminary data and is not for operational use.

This animation shows detections over northern Europe as far north as 58 degrees latitude in Scotland. During the morning and noon hours, small and short-lived isolated storms can be seen forming in the southeast and western areas of the UK and further north in Scotland. In the afternoon, the storms in the south merge and form a larger oval mesoscale convective system that is moving north-westwards, then gradually weakening during the evening in intensity and the amount of lightning generated. Meanwhile, another smaller and less intense storm cluster can be seen in Scotland, moving east to west. A lot of lightning activity is also visible to the south of the UK, over France and Spain. This animation, zooming in on the UK and Ireland in Europe, was made using about thirteen-hours’ worth of data from the MTG-I1 Lightning Imager’s north camera, from 09:00 to 21:59 UTC 12 June 2023. It was made from raw preliminary data and is not for operational use.

MTG-I1’s Lightning Imager makes detections far from the centre of the field of view of the camera, right up to near the horizon in South America. The elongated oval shape of flashes/storms close to the edge is the effect of the Lightning Imager’s large viewing angle in that part of its field of view. The daily cycle of lightning is clearly shown, with fewer storms during the morning hours when the daylight has just arrived and the most lightning activity during the late afternoon and early evening hours, around sunset. The animation also shows that much more lightning occurs in the northern part of South America (top left in the animation) compared to the areas further south (bottom left in the animation). This is the effect of Northern Hemisphere late spring/summer when the main trigger of tropical thunderstorms, the Intertropical Convergence Zone (ITCZ) moves to the north of equator. This animation, zooming in on South America, was made using five days’ worth of data from the Lightning Imager’s west camera, from 00:00 UTC 7 June to 23:59 UTC 11 June 2023. It was made from raw preliminary data and is not for operational use.

Central Africa is recognised as the most active lightning region on the planet. This five-day animation shows the continuous lightning activity in the region. Most of the time, especially during afternoon and evening hours, thunderstorms cover a considerable part of the area. Both localised storms - small isolated regions of lightning activity - and large mesoscale convective systems - large clusters and long narrow bands of lightning activity - can be seen. The storms are moving gradually westwards in the general easterly airflow, a characteristic of the Intertropical Convergence Zone (ITCZ). Sun glint can be seen moving in the top righthand corner of the video every day before noon. This animation, zooming in on central Africa, was made using data from the MTG-I1 Lightning Imager’s east camera, from 00:00 UTC 7 June to 23:59 UTC 11 June 2023. It was made from raw preliminary data and is not for operational use.

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 localized 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 MTG-I1 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.

This animation demonstrates the capability of Lightning Imager to monitor single convective systems in great detail. This close-up view of a mesoscale convective system in the Sahel region in northern Africa shows the westward movement and evolution of a big cluster of tropical thunderstorms. The system is driven by an African easterly wave that stretches further north and south from the main convection at the beginning of the animation, visible as a narrow line of clouds travelling from east to west with the main storm cluster. Later in the afternoon when the air has heated up, a line of new storms is triggered along the wave, forming a bow-like line of thunderstorms. The animation shows how the lightning is most frequent along the leading edge of the storm system. Sun glint can be seen crossing the field of view as the day develops. This animation, zooming in on the Sahel region in Africa, was made using about 13 hours’ worth of data from the MTG-I1 Lightning Imager’s east camera, from 04:00 to 16:55 UTC 6 June 2023. It was made from raw preliminary data and is not for operational use.