The lightning chart shows cloud-to-ground lightning strikes that have occurred in the last three hours. Those strikes marked white have occurred most recently, grading to the blue strikes, which have occurred the furthest in the past.
Therefore, the direction of movement of storms can be ascertained by tracking lightning from the blue strikes through the red strikes to the white strikes.
The lightning tracker is more accurate across southern and eastern Australia as this is where the majority of its detection sensors are located. The tracker will not detect cloud-to-cloud or intracloud lightning strikes.
15:16 EST Two teenage girls have been taken to hospital after lightning strikes near their school oval in Sydney's south-west.