Which cloud type is described as a grey layer with a uniform base that may produce drizzle or snow grains?

The cloud type described as a grey layer with a uniform base that may produce drizzle or snow grains is indeed Stratus. Stratus clouds are typically low-level clouds that form in a horizontal layer, covering the sky like a blanket. Their uniform appearance is characterized by a widespread and even texture, which can result in overcast conditions.

While Stratus clouds can produce light precipitation such as drizzle or light snow, other types of clouds like Cumulus are more associated with fair weather and develop vertically, leading to a more puffy appearance. Nimbus clouds relate to rain-bearing systems, but they are generally thicker and more associated with various forms of precipitation beyond just light drizzle or snow grains. Cirrus clouds, on the other hand, are high-altitude clouds that appear wispy and do not typically produce precipitation.

Understanding the characteristics of Stratus clouds is crucial for recognizing weather patterns since their presence often indicates overcast conditions that could lead to light precipitation.