A Maghera storm-chaser has captured images of a dramatic funnel cloud developing near Glenshane.
A funnel cloud is a spinning column of air and cloud that remains airborne and does not reach the ground.
It is only classified as a tornado if the rotation makes it to ground level.
Martin McKenna, an amateur astronomer and photographer, spotted the funnel on Tuesday afternoon.
"A friend and I watched this in amazement as it rotated rapidly with several vortices inside rotating around one another," he said.
"All the while this was going on there was thunder and blue cloud to ground lightning at the same time," he said.
"The lightning almost struck my car several times, the hail was very intense and the roads were flooded in places.
"The entire thunderstorm was rotating for a very long time - excellent action!"
Martin spends much of his time hunting comets, meteor showers and unusual atmospheric phenomena. The Maghera native even has an asteroid named after him.
Images of more funnel clouds, together with sundogs, moon-bows and more can be found on Martin's website.