waterspout

The strong winds which accompanied the storm cloud began to swirl above the Brisbane River at Kangaroo Point, causing a short-lived waterspout, the name for a tornado over a body of water.

That contradicted previous reports that had identified the cause as a waterspout, or mini tornado at sea.

Like tornadoes, waterspouts develop when differing wind directions cause the air in part of a storm cloud to rotate, forming a column of rapidly spinning air that descends down to the surface of the ocean.

He said it can be confused with tornadoes or waterspouts because the damage caused can be similar.

It was previously believed the vessel may have sunk because of a waterspout, but the Italian Air Force has now confirmed the most likely cause was a localised, powerful wind known as a downburst.