puffy masses or parallel bands
Mid-level clouds have cloud bases typically between 6500 to 23000 feet
(2000 to 6000 meters). Because of their
lower altitudes, they are composed primarily of water droplets.
However, when the temperatures are cold
enough, they can be composed of ice crystals as well.
Altocumulus clouds generally appear as puffy masses and are
located roughly 3-4 km above the ground. One part of the cloud darker than the
rest, a characteristic which makes them distinguishable from the higher
Altocumulus typically form from gradual lifting of air ahead of
an advancing cold front.
|In other instances, altocumulus clouds are aligned in parallel waves or
bands. 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, occasionally followed by thunderstorms later in the afternoon.