Know the weather

Long-term observation and practice show that the generation and dissipation of clouds, as well as the evolution and transformation among various clouds, are all carried out under certain conditions of water vapor and atmospheric movement. People can't see water vapor or atmospheric movement, but they can see every move of water vapor and atmospheric movement from the evolution of clouds. Clouds play an extremely important role in weather phenomena such as rain, snow, freezing hail.

For thousands of years, the working people in our country have summed up rich experiences of "knowing the sky by observing the clouds" according to the changes in the shape, direction, moving speed, thickness and color of clouds in production practice, and have compiled these experiences into proverbs. Here is a summary of these proverbs about "seeing the weather from the clouds". Interested friends may wish to make some observations and comparisons.

"There are hook clouds in the sky and rain in the ground": Hook clouds refer to cirrus clouds. Behind this cloud, there are often fronts (especially warm fronts), low pressure or low pressure troughs moving, which indicates that rain is coming;

"Battery cloud, rain": Battery cloud refers to fort-shaped high cumulus cloud or fort-shaped stratocumulus cloud, which appears in front of the trough with low pressure, indicating that the air is unstable, and thunderstorms usually come every 8- 10 hours.

"Clouds pass through clouds, and it rains": Clouds passing through clouds means that the moving directions of the upper and lower clouds are inconsistent, that is to say, the heights and winds of clouds are inconsistent, and they often appear near the front or low pressure, so it indicates rain. Sometimes the wind direction of the cloud is opposite to the ground, and there is a saying that "the sky changes when the cloud goes against the wind".

"The river pig crosses the river, and it rains heavily": The river pig refers to the broken rain clouds in the nimbostratus. The appearance of this cloud indicates that there is a lot of water vapor in nimbostratus, and a rainstorm is coming. Sometimes broken rain clouds are blown to cloudless places by strong winds, and it is also a precursor to rain to see clouds like river pigs floating across the "Milky Way" at night.

"Cotton cloud, rain is coming": Cotton cloud refers to flocculent cumulus clouds. The appearance of this cloud shows that the middle atmosphere is very unstable. If there is enough water vapor in the air and there is upward movement, cumulonimbus clouds will form and thunderstorms will come.

"Gray cloth hangs over the sky, and the rain will continue": Gray cloth cloud refers to nimbostratus, which is mostly formed by thickening and metamorphosing high-level clouds, with a large and thick range, and sufficient water vapor in the clouds, which often produces continuous precipitation.

"Cloud to the east, chariots and horses to; The clouds go south and the water rises; Clouds to the west, covered with hemp fiber; Clouds going north are good for drying wheat ":according to the moving direction of clouds, it is predicted that the weather will be fine, and the clouds will move east and north, indicating that the weather will be fine;" "The movement of clouds to the west and south indicates that it is going to rain. The direction of cloud movement usually indicates the wind direction at its height. This proverb shows the distribution of clouds in different parts of low pressure. Suitable for all-day dense, low and fast-moving clouds.

"Fish-scale day, even if it doesn't rain, there will be wind": Fish-scale day refers to cirrocumulus. The appearance of such clouds indicates that the upper atmosphere is unstable. If the clouds continue to decrease and thicken, it means that this area is already in front of a trough of low pressure, and it will rain or wind soon.

"The carp spots in the sky don't need to be turned over in the sun." Carp spot refers to semi-transparent cumulus clouds, which are often controlled by denatured high-pressure air masses that are cold and warm. If the clouds don't continue to thicken, it will be sunny in the short term.

"Dark clouds catch the sunset, and it will not fall tomorrow or tomorrow": When the sun goes down, a wall-like dark cloud rises under the western horizon to catch the sun, indicating that the dark cloud moves eastward, and the rainy weather system in the west moves, and it is going to rain. Generally speaking, if the clouds catch up, it will rain that night; If it is connected with the high clouds, it will rain the next day. However, if the dark clouds in the west are lumpy or discontinuous, or some areas are cloudy, it is not a sign of rain in the future.

"The northwest sky is unlocked, and the sun shines brightly": It means that in rainy days, the clouds in the northwest crack and reveal a blue sky, which is called "the sky is unlocked". This shows that the local area is at the back of the rainy weather system. As the rainfall system moved eastward, the local rain stopped and the weather improved.

"It's sunny now, but I haven't seen it for three days": In spring and summer, at noon on rainy days, the clouds split and the sun appeared, but the clouds quickly gathered and thickened, indicating that the local area was affected by the quasi-static front, and the airflow near the quasi-static front fluctuated strongly and changefully. When the updraft increases, the clouds become thicker and the rainfall increases; When the updraft weakens, the clouds become thinner and the rainfall decreases or stops; Around noon, the sun shines strongly, the upper part of the cloud is heated and evaporated, or the updraft below the cloud weakens, and the zenith cloud will split. As the sun's exposure decreases, or the updraft under the clouds strengthens, the divided clouds will gather again and become thicker. So the proverb "The sun appears now" often indicates that it will continue to rain. This proverb is similar to such proverbs as "the sun laughs, the temples are drenched" and "when it shines, it falls ten feet".

"Sunset shoots at the foot, and the rain falls within three days": it means that the sun shines through the cracks in the clouds, which is called "sun shoots at the foot". In the evening, the sun shoots at the foot, indicating strong convection and indicating rain.

"Don't go out in the morning and take Wan Li Road at night": There are no clouds in the east and clouds in the west in the morning. Sunlight shines on the clouds, scattering rosy clouds, indicating that there is a lot of water vapor in the air or a rainfall system moves in, and the air is generally unstable during the day, so the weather will turn rainy; If there is a sunset glow at night, it means that the sky in the west has cleared up, and the general convection is weakened at night. The clouds in the east that form the rosy clouds will move eastward or tend to dissipate, indicating that the sky is clear.

"Long sunny, foggy and cloudy, long cloudy and foggy and sunny": refers to the appearance of fog after a long sunny day, indicating that the warm and humid airflow moves and the air is humid, which is a sign of cloudy and rainy; Fog appears after a long cloudy day, indicating that the clouds in the sky become thinner, split and dissipate, and the ground temperature drops, so that water vapor condenses into radiation fog. After sunrise, the fog will disappear and sunny days will appear.

In the morning of warm season, if there is a castle cloud on the horizon, it means that the humid atmosphere at this height is already very unstable. At noon, once the low-level convection develops, the upper and lower unstable layers will merge, resulting in strong convective movement, cumulonimbus clouds and thunderstorms. So there is a proverb "pagoda clouds in the morning, and it rains cats and dogs in the afternoon".

In addition, clouds with weather omen often have certain continuity, seasonality and locality in the evolution process. The clouds in the sky move from a distance in the order of cirrus, cirrostratus high-level clouds and nimbostratus, and gradually change from less to more, from high to low, from thin to thick, indicating that rainy weather is coming; On the contrary, if the clouds change from low to high, from thick to thin, and from layered clouds to scattered clouds, there will be no rainy weather. In the warm season morning, if there are flat, convex and isolated clouds (light cumulus clouds) or white broken clouds (broken cumulus clouds) in the sky, it means that the air in the middle and lower layers is relatively stable and the weather is fine. The lingering smog is harmful to human respiratory system and cardiovascular system.

In addition, the color of clouds can also indicate some kind of weather. For example, the color of hail cloud is first white and then black, and then red appears in the cloud, forming a white, black and red distorted cloud with khaki edges. Black is caused by the sun's inability to penetrate clouds; White is the result of non-selective scattering or reflection of sunlight by clouds; Red and yellow are the phenomena that some cloud droplets (ranging from one thousandth to one hundredth of a millimeter in diameter) selectively scatter sunlight. Sometimes rain clouds are pale yellow, but the color of the clouds is uniform and will not stir. There are also many proverbs that hail comes from the color and shape of clouds. For example, in Inner Mongolia, there are proverbs such as "Not afraid of black clouds, but afraid of red clouds, and most afraid of white worms in Huang Yun", and in Shaanxi, "Huang Yun turns over", and clouds are seen in groups; There are proverbs such as "When clouds fight, hail will fall" and "Huang Yun is full of red clouds, and there are many hail disasters due to repeated cloud disturbances". There are also some sayings, such as "the dark clouds roll into a ball in the afternoon, and the wind, rain and hail come together" and "the sky is yellow and sultry, and the Tianhe water roared to prevent ice eggs", all of which indicate that when the air convection is strong, the clouds develop rapidly and rush straight up like smoke.