A storm crossing the Chesapeake Bay on July 1. ( Brock Thompson via Twitter )

Saturday’s storms were not out of the ordinary. They unleashed a burst of wind and rain and went along their merry way.

But as they approached, they appeared far more sinister. Watching them from the Chesapeake Bay, you might have thought the apocalypse was coming.

Along their leading edge, the storms displayed a menacing, arced wall of low-hanging clouds, known as shelf clouds, or shelfies for short.

CWG’s Angela Fritz described how these clouds form in a previous post:

Shelf clouds are common ahead of thunderstorms that form into lines — things like squall lines, bow echoes or derechos — and are usually indicative of strong wind gusts. They develop as the cool, moist outflow gets sucked back up into the storm. Because of the relatively low temperature and high moisture content in this pool of air, it condenses to form a cloud at a lower level than the surrounding storm clouds.

Below, find more great photos of these scary-looking clouds:

From the Bay

Clouds over Chesapeake Beach on July 1. (Eunice Lin via Facebook)

Approaching Washington

More shelf clouds:

The dramatic shelf clouds that devoured the Wisconsin skies

A wicked-looking shelf cloud rolls through Kentucky and Ohio (Photos)

Time lapse: Shelf cloud, hail sweep through Sydney

Photos: Ominous shelf clouds roll through Nebraska and Kentucky

Towering ‘mother ship’ storm mesmerizes and menaces Washington region