Cumulonimbus and shelf cloud over Beauport Picture Jo Huelin Riley (36053655)

BEACHGOERS had their sunbathing briefly interrupted on Tuesday when a rare shelf cloud rolled in.

The skies suddenly turned black as a cumulonimbus storm cloud – with the shelf cloud sitting beneath it – clipped the western parishes on what had been a warm and sunny day.

It also brought with it a short-lived torrential downpour – depositing up to 3mm of rain in just a few minutes – and a blast of strong winds.

Dozens of Islanders took pictures and filmed the unusual cloud before it headed off north and fizzled away.

Shelf clouds are spectacular, low-level long and thin clouds which are associated with storms.

They form when a cold downdraught from a cumulonimbus reaches the ground and spreads out, pushing existing warm air upwards.

The air rises slightly and cools and condenses – forming a long strip of cloud.