Materials about understanding the weather by observing clouds.

Weather conditions are very important for outdoor athletes, because most of the bad weather is caused by sudden changes in the weather. In order to enjoy a happy outdoor life, while listening to the weather forecast, tourists need to master certain climate knowledge, learn to read clouds and know the weather, so as to cope with the abnormal weather changes calmly.

There are 10 cloud forms, in which the word "product" means that the shape of the cloud is massive (regardless of size) and the word "layer" means that the sky is full of gloomy clouds. Each type gives the approximate height of distribution, and the higher the cloud, the better the weather. In the polar regions, the same type of clouds will appear in the sky at lower altitudes.

Cirrocumulus: Small round cumulus clouds that look like ripples are often called "fish scale sky". Usually, the altitude is between 5 000 and 8 000 meters, which usually indicates sunny weather.

Altocumulus: Similar to cirrocumulus, it means good weather, but it covers a wider area, and the clouds are thicker and dark white. It usually appears after heavy rain and is suspended at an altitude of 5 000~6 000 meters.

Cumulonimbus: It's a low-level Lei Yun with dark clouds. The tower cloud can be as high as 6,000 meters, and the flat cloud at the top is called anvil cloud. Cumulonimbus clouds often bring strong storms and lightning. The upper layer resembles a false cirrus cloud and the top layer resembles a false rain cloud.

Cumulus: It is easy to identify, fluffy white clouds, like floc, floating in the air. If we are separated, it will mean another beautiful sunny day, but if it gets bigger and bigger and there are more and more front ends, it is likely to bring a sudden rainstorm. Cumulus clouds in the blue sky at sea usually indicate that they are not far from land, and the height is generally not more than 2500 meters.

Cirrus: a high-level bunchy cloud formed by ice crystals, which is why it looks pure white. Often called ponytail cloud. They usually mean sunny weather, 5000-9000 meters high.

Cirrostratus: It is made of ice particles and looks like white clouds. These are the only clouds that glow around the sun or the moon. If cirrostratus expands, it means the weather is fine; If cirrostratus shrinks, it means it will rain; If the sky is covered with cirrus clouds, the sky above the cirrus clouds will darken and gradually form a cirrocumulus, which indicates the coming of rain and snow.

High-level cloud: It looks like a gray curtain in the sun or moonlight. If wet air approaches, the cloud disk disappears, and the clouds become thicker and darker until it rains, and the height can reach 2500 ~ 6000 meters.

Nimbostratus: It's a low-level dark cloud hanging in the air, which means it will rain within 4 hours, usually lasting for several hours.

Stratocumulus: A low-level tiled cloud that usually covers the whole sky. Clouds are thin and sunlight can pass through. They may bring thunderstorms, but they usually disappear in the afternoon, leaving a clear and bright blue sky. The height is less than 2500 meters.

Stratus clouds: clouds are the lowest, hanging in the air like dense fog. When they first appeared, they were often mistaken for mountain fog. They are not natural rain clouds, but they can also form Mao Mao rain. If it gets thicker and thicker at night and covers the morning sky, it will usually be sunny and the height will not exceed 2500 meters.