This is the terrifying moment a large shelf cloud darkened the sky in southern Thailand.

Footage shows the ominous cloud formation looming over buildings in Yala province on June 8 afternoon.

The Thai Meteorological Agency had warned that isolated heavy rain was expected throughout the country, including the southern provinces.

This is the terrifying moment a large shelf cloud darkened the sky in southern Thailand.

Footage shows the ominous cloud formation looming over buildings in Yala province on June 8 afternoon.

The Thai Meteorological Agency had warned that isolated heavy rain was expected throughout the country, including the southern provinces.

Shelf clouds are expansive clouds formed on the leading edge of a storm system. They form when denser cold air within the storm rushes out and lifts warm air, which then condenses into clouds.

They are different from wall clouds, which are smaller and more compact, and are formed when the cloud base of a supercell or rotating storm lowers to the ground.