Why does it rain and snow in the sky? Why does it sometimes rain and sometimes snow?

Because there's steam.

Hail, like rain and snow, falls from the clouds.

Hail plague will occur in summer, meteorologically the so-called precipitation refers to the natural phenomenon of water falling from the atmosphere to the ground, including rain, snow, hail and so on.

Clouds are formed by water vapor. In the high altitude, due to the low temperature, the particles suspended in the air absorb the water in the cloud and form very small water droplets or ice crystals, which continue to absorb the water in the cloud and gradually form larger water droplets (Xiaoice crystals can also become larger water droplets when absorbing a large amount of water). As they absorb the water from the clouds, the droplets grow until their weight exceeds the levitating force that the air can provide, and then they fall to the ground to form rain.

If the temperature is very low, the water precipitated in the cloud is frozen into Xiaoice crystals (the extremely small water droplets that have formed in the cloud can also be frozen into Xiaoice crystals), and the Xiaoice crystals absorb water and continue to expand, forming hexagonal larger ice crystals, and when the hexagonal crystals are large enough to exceed the buoyancy of the air, they fall into snow.

Hail is the size of ice particles and ice that fall from the sky, and its particle size is generally 5-10 mm, and the largest particle size recorded in the literature can reach more than 300 mm. Hail from the sky can cause great damage to houses, people, livestock, crops, etc., and form a disaster. Hail is a product of convective weather, formed in thick and strong cumulonimbus clouds, and meteorologically said to be deep stratification without concealment.

Relatively large ice particles can be produced in the development of thick cumulonimbus clouds. However, it does not necessarily fall to the ground and become hailstones, only when those ice particles rise and fall repeatedly in the high-altitude clouds with the air current, and continue to grow to a large enough particle, they will fall from the sky into hail.

In fact, there is a saying that is particularly good, the sky has unpredictable circumstances, and people have good and bad luck. Whether it rains or snows depends on the weather and temperature, and in summer, it will rain in normal times, but in winter, if the weather reaches a certain temperature, then it will snow.

When the water vapor evaporates and rises to a high altitude, it will condense and the particles will accumulate into large water droplets, and when the mass reaches a certain level, it will be attracted by the earth and fall to the ground.

If the surface temperature is too high, it will turn into rain, and if it is too low, it will turn into snowflakes.

It snows in the winter and rains in the summer, and this is because of the temperature, but this is a natural phenomenon, and it is a very normal phenomenon.

Rain and snow are both a weather condition.

Rain and snow are essentially the same.

Snow is due to low temperature, water vapor condenses into snowflakes, while rain is just the right temperature.

Because it depends on the temperature.

Everyone wants to have sunny days every day, so they don't have to wear an umbrella and don't have to worry about the rain getting wet, rain and snow are the two most common forms of precipitation in nature, but how do they form and fall? Why does it rain and snow in the sky? What is the reason for this?

I believe that many friends don't know much, so let me answer your doubts.

We all know this: hot air rises, cold air sinks. As the hot air rises, it cools down and the water vapor in the air condenses into tiny droplets or ice crystals.

The small water droplets or Xiaoice crystals that make up the cloud collide with each other in the cloud and constantly merge into larger water droplets or ice crystals. When they are so large that the air can no longer hold them, water droplets or ice crystals fall from the clouds. If the temperature in the lower atmosphere is high, the ice crystals melt into liquid water droplets, forming rain; If the temperature of the lower atmosphere is low, small Xiaoice crystals in the upper altitude gather together and fall to the ground in the form of snowflakes.

Generally speaking, the diameter of raindrops is not less than millimeters, but there are also very small ones, and when the diameter of the falling water droplets is less than millimeters, it is called drizzle. Drizzle is not as we think, it is just a description of rain with low intensity. Decide whether it's rain or drizzle.

It is the size of the diameter of the water droplet, not the intensity of the precipitation. In fact, drizzle can be more intense than rain, and don't be paradoxical when you hear the word "strong drizzle".

Sleet is a half-melted snow (wet snow), or rain and snow falling at the same time, which can occur when the air temperature near the surface is slightly above 0 and the air temperature above is below 0. Freezing rain, composed of water droplets whose temperature is lower than 0 but does not freeze (meteorologically called supercooled water droplets), when the weather is cold and the temperature is low, the freezing rain droplets fall, and when it falls on objects with a temperature lower than 0, it will immediately freeze and attach to the object, forming rime. There are two conditions that need to be met for freezing rain to occur:

First of all, the cold air is relatively strong, causing the ground temperature to reach below 0; Secondly, there must be a warm and moist air current, and the air is rich in water vapor in order to form rainfall. What's more, when freezing rain is formed, there is a unique three-layer structure in the atmosphere, like a piece of sandwich candy, cold at the top and warm in the middle. Freezing rain often accumulates on tree branches or power lines, crushing them when they reach a certain level of weight, causing serious damage.

Rain: Water on the surface of land and sea evaporates into water vapor, which rises to a certain height and becomes small droplets when cold. These small droplets make up the cloud, and they collide with each other in the cloud and merge into large droplets.

When it was too big for the air to hold, it fell from the clouds and formed rain.

Snow: Water from the ocean and the ground evaporates into the sky, and this water vapor travels with the wind to other places, and when it encounters cold air, it forms precipitation and returns to the earth's surface. There are two types of this precipitation:

One is liquid precipitation, which is rain; The other is solid precipitation, which is snow or hail, etc.

It's all precipitation in nature. Snow temperatures are required.

Snowfall falls under the category of precipitation.

Precipitation refers to the phenomenon of water vapor condensing in the air and falling to the surface of the earth, which includes two parts, one is the condensation of water vapor in the atmosphere directly on the surface of the ground or ground objects and at low altitudes, such as frost, dew, fog and fog, also known as horizontal precipitation; The other part is the water vapor condensate that falls from the air to the ground, such as rain, snow, hail and rain song, also known as vertical precipitation. However, simple frost, dew, fog and fog are not treated as precipitation. In China, the National Meteorological Administration's surface observation norms stipulate that precipitation only refers to vertical precipitation, and horizontal precipitation is not treated as precipitation.

More than 50 mm of precipitation in one day is heavy rain (heavy rain), more than 25 mm is heavy rain, 10-25 mm is moderate rain, less than 10 mm is light rain, more than 75 mm is heavy rain (heavy rain), and more than 200 mm is extremely heavy rain.

In fact, the process is the same, it is the condensation of water vapor, the difference is that when the temperature is high, it will form rain; If the temperature is too low, snow will form.

To add to this, there is sleet in this kind of weather.

Clear skies generally don't snow. However, due to the different cloud layers, one layer is snow and the other layer is rain, so sleet can be formed.

Both snow and rain are formed by the condensation of clouds in the air, or small droplets of water, when cold. But it all needs a nucleus in the early stages of its formation. This nucleus is generally acted by dust in the air.

When the temperature gets colder, the temperature of the dust droplets drops faster than the temperature of the water droplets, then the small water droplets will gather and cling to the small dust to form larger water droplets, and when it is big enough to be heavier than the air, it will fall, and the more it falls, the bigger it will be, so that rain is formed. And when the temperature is very cold at high altitude, it is not rain, but snowflakes or hail. This happens at high altitude, but if the temperature is high at low altitude, some of the snow will melt into water, and when it reaches the ground, it will become rain and snow.

Hehe, because the temperature is not low enough.

The temperature is high when the snow arrives at the place.

It melted into raindrops.

1. The air is supersaturated, 2. There must be condensation nuclei, 3. Cloud droplets become raindrops, 4. Overcome resistance and jacking.

The first two are conditions for water vapor condensation, and all four are conditions for rainfall.

The main way to supersaturate the air is to cool the air up.

Sometimes, fog is formed when the air cools so dramatically near the ground that the air does not need to rise to cool down to become supersaturated.

Due to the water cycle in nature all the time, water in different places is evaporating into the atmosphere at different speeds to form water vapor, which can form precipitation forms such as rain, snow, hail, and freezing rain as long as the conditions required for precipitation are met.