Water spout filmed over Lough Neagh in Northern Ireland
4 June 2014 Last updated at 11:18 BST
Staff at Belfast International Airport witnessed a water spout forming over Lough Neagh on Tuesday evening.
A funnel cloud usually forms during a thunderstorm or heavy shower, from a cumulonimbus cloud or a large cumulus cloud, when the atmosphere is unstable.
It consists of condensed water droplets and is associated with a column of air that rotates as it is drawn into the cloud.
If a funnel cloud touches the ground it is generally regarded as a tornado and could lift debris and even cause some minor damage on the ground - depending on the strength of convection within the cloud.
However, if the funnel cloud touches down at sea we get what is known as a waterspout.