layer cloud

In meteorology, a "layer cloud" refers to a cloud that forms a broad, continuous sheet across the sky. The prefix "strat-" in a cloud's name indicates this layered formation.1

Different types of layer clouds exist based on their altitude and characteristics:
* Stratus: Low-lying, gray layers that cover large areas.1
* Altostratus: Mid-altitude, dark gray layers.1
* Cirrostratus: High, thin layers that can cover the entire sky.1
* Nimbostratus: Low, dark gray layers that typically produce continuous light precipitation like rain or snow.1
* Stratocumulus: A more wintry version of cumulus clouds, spreading out in a flat layer, sometimes dense enough to obscure the sky.1

Clouds form when moist air rises, expands, and cools to its dew point, causing water vapor to condense onto tiny particles called condensation nuclei. These droplets or ice crystals form visible clouds. Layer clouds are often associated with widespread, regular ascent of air.23