Altocumulus Clouds

Altocumulus clouds generally appear as puffy masses,

or are sometimes aligned in parallel waves or bands.

One part of the cloud is usually darker than the rest, which makes it distinguishable from the higher cirrocumulus. These clouds are a result of slow lifting that is common ahead of an advancing cold front, and are typically located about 3-4 km. above the ground.

In the presence of rising air at cloud level, altocumulus take on the appearance of "little castles", and these clouds are often seen on warm, humid summer mornings, sometimes followed by thunderstorms later in the afternoon.