Why is it easy to have "freezing rain" in Guizhou in winter?

When the strong cold air meets the southbound warm and humid airflow, the cold air is inserted under the warm air like a wedge, and the near-surface temperature drops below zero, and the humid warm air is lifted to form clouds, causing rainfall. When raindrops fall from the air, because the temperature near the ground is very low, a layer of crystal clear thin ice will form on the surface of telephone poles, trees, vegetation and roads, which is called "freezing rain" in meteorology. In some areas of southern China, freezing rain is also called "ice falling", while in northern China, it is called "gutter oil". Rain that freezes immediately after raindrops collide with the ground, ground objects, airplanes and other objects is called freezing rain. This kind of rain is supercooled water drops below 0℃ falling from the sky. When it comes into contact with branches, wires, hay or other ground objects, it will freeze into a smooth, crystal-clear ice shell on these objects, and sometimes it will freeze like an icicle. This kind of ice layer is also called "rime" or ice in meteorology. Freezing rain is a transparent or translucent ice layer formed by supercooled raindrops or Mao Mao rain whose temperature is lower than freezing point, and the water drops quickly freeze on the ground and objects. This kind of ice layer can form a magnificent scene of "thousands of cliffs in the ice and thousands of peaks in the crystal". If it rains in Mao Mao, particles will appear with rough surface and clear particle structure. In case of heavy rain or heavy rainfall intensity, clear ice mounds often form. The surface of the ice clearing mound is smooth, transparent and dense, and it often freezes when flowing on wires, branches or ships, forming long ice hangings. Freezing rain mostly occurs in winter and early spring. In China, Guizhou is the region with more freezing rain, followed by Hunan, Jiangxi, Hubei, Henan, Anhui, Jiangsu, Shandong, Hebei, Shaanxi, Gansu and southern Liaoning. Among them, there are more mountains than plains, and the mountains are the most. Can rain fall from the sky and turn into ice? Yes, when this kind of ice accumulates to a certain extent, it is not only harmful, but also harmful.

These are the reasons why it rains in winter. Guizhou province is located in China's subtropical monsoon climate zone, and its winter location happens to be the intersection of southeast monsoon, southwest monsoon and northwest monsoon. Cold and warm air meet here, often evenly matched, which causes long-term rainfall. Such conditions are the first step in causing freezing rain.

Secondly, because Guizhou is located in the plateau, the weather is colder than that in the same latitude area. Take Guiyang as an example, the average temperature in winter is only 5 degrees, and it often hovers at 0 degrees in case of cold wave, which is the second step to cause freezing rain.

Thirdly, because the cold and warm air forms a quasi-static front here, the warm air is lighter in the upper part and the cold air is heavier in the lower part, so the temperature in the cloud is even higher than that near the ground. Therefore, when clouds cause rainfall, raindrops do not form ice crystals at high altitude, but exist in the form of small water droplets. In the process of falling, the temperature of water droplets decreases due to the temperature drop. But if the water drops fall to the ground before freezing, it will form freezing rain. In Guizhou, because of the high terrain, the clouds are far from the ground.

In a word, because its topography, geographical location and water vapor conditions are isomorphic conditions for the formation of freezing rain in Guizhou, Weining County in Bijie Prefecture of Guizhou Province is known as the "hometown of freezing rain in China".