Reading Clouds: From "The Secret Naturist Handbook"
Reading Clouds
When studying the weather forecast one of the elements mentioned, though not in all cases, is the amount of cloud cover. Cloud cover is expressed as a percentage, for example, 50% means that clouds obscure half the sky. This is useful to know as the amount of cloud cover can effect what the secret naturist can and cannot do. A few examples.
Thick, dark clouds in the evening will mean it gets dark earlier and there will be no moonlight or even starlight to help you see your way in the dark. It can also be especially dark in woodland at such times as well. The amount of cloud will also govern how quickly it gets cold later in the day as clouds help stop the heat from the sun radiating back into space. Good cloud cover after a hot sunny day can keep evening temperatures much higher than under a clear sky.
Clouds cover also offers some degree of protection from sunburn but should not be relied upon totally as you can still get sunburn through clouds. At the very least the shade offered my clouds on a hot day can be most welcome. Another type of cloud cover, fog or mist also has much to offer the secret naturist. See separate page in contents for more.
One of the most useful tricks is to stop occasionally, long enough to study what the clouds are doing. Notice the direction and speed as this will tell you where the weather is coming from, as well as the colours of the clouds. We all know the dark ones can mean a storm, but the light ones can turn dark very quickly. In the winter, the cloud masses are often so large they cover the sky, therefore you will need to look more for wind and temperature changes.
There are also many different varieties of clouds and each can signify different weather conditions. The following are general examples and should be used only as a guide.
Cirrus
These clouds are the very high clouds that look like thin streaks or curls. They are usually 6 km or more above the earth and are usually a sign of fair weather. In cold climates, however, cirrus clouds that begin to multiply and are accompanied by increasing winds blowing steadily from a northerly direction indicate an oncoming blizzard.
Cumulus
These are fluffy, white, heaped-up clouds. These clouds, which are much lower than cirrus clouds, are often fair weather clouds. They are apt to appear around midday on a sunny day, looking like large cotton balls with flat bottoms. As the day advances, they may become bigger and push higher into the atmosphere. Piling up to appear like a mountain of clouds. These can turn into storm clouds.
Stratus
There is not much precipitation from stratus, because it is a shallow cloud, but may produce slight to moderate drizzle and ice crystals or fine snow in cold weather.
Stratocumulus
A low layered cloud with some observed structure and varying colour. Often stratocumulus is the result of both mixing and low-level instability. A sign of blustery and relatively cool conditions with possible showers or rain or snow but may not reach the ground.
Altostratus
This is a dull, medium level, white or bluish grey cloud. It forms by slow ascent of air over a wide area, especially ahead of a warm front or occlusion where it is often a precursor of rain. Sun may be dimly visible as through ground glass. Often a sign of approaching rain or snow.
Altocumulus
A patchy cloud with a wave-like or dappled appearance. Distinguished from Cirrocumulus by the colour which is grey or blue grey (Cirrocumulus is milky-white). Sometimes referred to as a "Mackerel sky".
Nimbostratus
This is a dark, grey, heavy sheet of cloud from which rain or snow is falling. It appears black from below but as the rain or snow becomes heavier the base may become indistinguishable with just ragged scuds of low fractostratus to be seen. The rain or other precipitation usually lasts for a long time. At a warm front it may continue for several hours, unlike the relatively short, intense rain from showers.
Cumulonimbus
A cloud formation resulting from a cumulus cloud building up, extending to great heights, and forming in the shape of an anvil. You can expect a thunderstorm if this cloud is moving in your direction. May produce very heavy rains, hail, strong winds and even tornadoes.
Cirrostratus
A fairly uniform layer of high stratus clouds that are darker than cirrus clouds. Cirrostratus clouds indicate good weather. A "halo" may appear about the sun or moon due to refraction of light rays in the ice crystals and is often a sign of approaching storms.
Cirrocumulus
A small, white, round cloud at high altitude. Cirrocumulus clouds indicate good weather.