Altocumulus are heaped masses or rolls of cloud, visible at mis-altitudes. They are usually white or gray, and often occur in sheets or patches with wavy, rounded edges. Altocumulus clouds are often the sign of approaching cold weather or, if they appear on a warm and humid morning, they may signal the develpment of thunderstorms. They are large clouds, fluffy clouds that are generally considered to be "fair weather" indicators.
Alto cumulus clouds are a sign of bad weather to come. When you see them in the autumn season, they are indicating a cold front.
When you see them on humid summer mornings, thunderstorms are likely to come durning late afternoon
Altocumulus clouds are white/gray and puffy, either floating in a neat row, or scattered across the sky. Theyare usually 1 KM thick. They float 2000-7000 meters in the air.
Altocumulus clouds are made mostly out of water droplets, and very little ice crystals.