Weather characteristics of heavy snow solar term when will ice flood occur
Four seas network: thousands of birds fly away, thousands of trails disappear, once the heavy snow solar term is over, it will come in the middle of winter, and it will appear in the coldest time of winter. What are the weather characteristics and phenomena of the heavy snow solar term? Let's take a look at it.
Basic features of heavy snow solar terms:
'the mountains are withered and gloomy, and the branches of trees are neighing all around. Snow wants to chant a sentence. She goes through branches and raids the courtyard to play plum blossom (zuohe River).
In heavy snow season, except for the winter areas in South China and South Yunnan, most of China has entered winter. The average temperature in Northeast and Northwest China is below - 10 ℃, and the temperature in the Yellow River Basin and North China is also stable below 0 ℃. At this time, there is snow gradually in the Yellow River Basin, while in the north, there is heavy snow.
However, in the south, especially in Guangzhou and the Pearl River Delta, the vegetation is still verdant, and the feeling of dryness is still obvious, which is quite different from the climate in the north. The climate in the south of China is mild in winter with little rain and snow. The average temperature is about 2 ℃ to 4 ℃ higher than that in the middle and lower reaches of the Yangtze River. The rainfall only accounts for about 5% of the whole year. There is occasional snowfall, most of which occurs in January and February; the snow on the ground is rarely seen once in three or five years. At this time, the climate in South China is also foggy. Generally, December is the month with the most foggy days.
Fog usually occurs in the morning when there is no cloud or little cloud at night. Meteorology calls it radiation fog. "Ten fog and nine clear", the fog mostly dissipates before noon, and the sun will be particularly warm in the afternoon.
Common weather phenomena:
1, cooling
Some people have made statistics. The month with the most strong cold air in China is November. The average temperature in December in most areas of the north is between & ndash; 5 ℃ and & ndash; 20 ℃. Frost sometimes occurs after the strong cold air in the south.
2. Heavy snow (Blizzard)
We know that strong cold air can often form large-scale snowfall or local blizzard. There are many benefits of snowfall, especially to alleviate winter drought, freeze to death of farmland diseases and insect pests, and to develop winter tourism. However, it is easy to cause civil aviation flight delay, road traffic accidents and lane congestion due to the slippery snow roads and ice melting; in some areas, snowstorms and road closures will also pose a threat to the human and animal safety of grassland (called white disaster) in pastoral areas.
3. Freezing rain (RIME)
When the strong cold air reaches the south, especially in Guizhou, Hunan, Hubei and other glaze areas, freezing rain is easy to occur. Freezing rain is the snowflake falling from the upper cold layer, sometimes melting into rain in the middle layer, and then becoming supercooled water of raindrops even though the temperature is lower than 0 ℃. Supercooled water drops fall from the air. When it reaches the ground and touches any object on the ground, it freezes immediately, forming freezing rain. When freezing rain occurs, there is a layer of uneven ice shell on the ground and objects, which will have a great impact on traffic, power and communication, and also cause damage to fruit trees. According to the statistics in the Book Climate in the middle and lower reaches of the Yangtze River, when the temperature in the middle and lower reaches of the Yangtze River is at & ndash; 3 ~ 0 ℃, freezing rain is easy to occur, and the probability of freezing rain is 76%.
4, rime
According to statistics, from November to February of the next year, there will be rime in northwest, northeast and most of the Yangtze River Basin, and the mountain areas with high humidity are more common. Rime is a milky white ice crystal deposit which is formed by the condensation of water vapor or the freezing of supercooled fog droplets. There are many rime days in winter in China: Heilongjiang, Jilin, Northern Xinjiang and Northern Shaanxi. Rime is a kind of natural beauty widely appreciated by people, but sometimes it also becomes a natural disaster. When it is serious, it will cut off the wires and trees, affecting the traffic, power supply and communication.
5, haze
In December, when the temperature is relatively low in the morning in the south of the Yangtze River just entering winter, or after rain and snow, there may be a large area of fog near the ground with high humidity. The haze in the northern cities will also meet.
6, ice flood
In winter, Baotou River in Inner Mongolia is frozen and closed, while Lanzhou River in the south is not. The river flows to the closed river section. Because the ice layer and ice dam in the closed river section block the river from the upstream and force the water level to rise, it is easy for Baotou river section to be flooded. If the strong cold air comes late, it is easy to cause the flood in December.
If we don't do a good job of ice flood prevention in advance, it will cause unnecessary loss of life and property. We should be careful to do a good job of ice flood in winter.