When do cumulus clouds appear

Their dark bases may be no more than m ft above the Earth's surface. Their tops may extend upward to over 12, m 39, ft. Tremendous amounts of energy are released by the condensation of water vapor within a cumulonimbus.

Lightning, thunder, and even violent tornadoes are associated with the cumulonimbus. As the process continues, water droplets continue to accumulate upwards, creating heaps visible in the sky as white, fluffy clouds.

Essentially, a cumulus-type cloud is a cloud that develops in a vertical direction from the bottom up. With increasing vertical height, cumulus clouds are often associated with convection.

Bases of these clouds are generally no more than 3, feet above the ground, but they can develop past the troposphere in both temperate and tropical latitudes. Cumulus clouds are classified as low yet vertically building clouds. Cumulus fractus clouds are cumulus clouds that appear in irregular fragments, as if they had been shred or torn apart. Cumulus humilis clouds are the so-called "fair weather" cumulus clouds.

They exhibit little or no vertical development and generally have a flat appearance. Their growth is usually limited by a temperature inversion or an increase in temperature with height , which is marked by the unusually uniform height of the clouds. In the Keys, cumulus clouds are usually based between 1, feet and 3, feet above ground, and can occur at any time of year. Type 1 cumulus clouds are flat and thin in appearance, and indicate that the air that is rising to form them is not able to rise very far.

These clouds are too thin to produce rain, lightning, or waterspouts. In the Keys, type 2 cumulus can occur at any time of year, and are very common in the Summer. When a cumulus cloud is much taller than it is wide, it is often called a towering cumulus TCU cloud. The taller these clouds are, the more likely they are to produce showers, and sometimes waterspouts.

A TCU producing a shower is shown in the third picture below. Type 3 cumulonimbus [CB] whose tops are not fibrous or in the form of an anvil : Cumulonimbus CB clouds are very large, tall, billowing cumulus clouds, sometimes referred to as thunderheads.

They often produce lightning, thunder, rain, sometimes waterspouts, and on rare occasions severe weather such as hail, high winds, or tornadoes. In the Keys, CB can occur at any time of year, but are much more common in the Summer months June through September than the Winter months December through February , because they usually need a very deep layer of warm, moist, rising air in order to form.

CB can occur in Summer under a wide variety of conditions, but in the Winter are usually caused by cold fronts moving into warm, humid air.

In the Keys, CB are usually based less than 2, feet above ground in the Summer, and sometimes slightly higher in the Winter. Type 3 CB are generally puffy and billowy on top, sometimes resembling the head of a cauliflower. They are not as puffy or sharp-edged as cumulus clouds, and tend to form in more relatively continuous layers.