Thunderstorm complex causes 400,000 lightning strikes over three Australian states

A large mass of thunderstorms known as a Mesoscale Convective Complex, or MCC, produced around 400,000 lightning strikes as it passed over parts of WA, SA and the NT between Thursday afternoon and Friday morning.

While most thunderstorms exist as individual storm cells, there is a rare phenomenon where a group of storms combine and act as a single complex. These storms systems are referred to as a Mesoscale Convective Complex (MCC).

MCCs are large and often long-lived thunderstorm systems that continually generate new storms at their leading edge. These new storms form when cold air spreading out from the existing storm complex lifts warm, humid air, triggering fresh thunderstorm development ahead of the MCC. Meanwhile, diverging winds high up in the atmosphere help ventilate the system, allowing powerful updrafts to persist and enabling the complex to survive for hours on end.

The series of images below combine satellite imagery with lightning strikes observations to show the movement of an MCC over parts of southern and central Australia this week. The storm complex initially formed over the southeast of WA on Thursday afternoon before moving towards the northeast and passing over parts of SA on Thursday night, then tracking over the southern NT on Friday morning.

Enhanced infrared satellite image combined with lightning strike observations
Image: Composite day/night satellite image and lightning observations during the 12-hour period ending at 4:30am ACST on Friday, October 16, 2026. Source: Weatherzone.

This MCC travelled around 1,000 km from WA to the NT between Thursday afternoon and Friday morning, with the storm system persisting for more than 12 hours.

Lightning was prolific as the MCC traversed parts of three states, with around 400,000 lightning strikes detected along its path by Weatherzone’s Total Lightning Network.

Image: Lightning strikes detected within an 800 km radius of Ernabella, SA between 4 pm AEDT Thursday and 1 pm AEDT Friday. Source: Weatherzone.

MCCs also form in other parts of the world and have been documented over the United States and South America, among other areas. These extensive storm systems have also been known to produce massive lightning bolts called megaflashes.

In 2017, a megaflash associated with an MCC over the United States caused a single lightning flash that was around 829 km long. This was the world’s longest lightning flash on record, and the enormous size of the MCC made this record possible.