What happened to the snowstorm in China in 2008?

On June 65438+ 10/0, 2008, a snowstorm broke out in the south. The severely affected areas are Hunan, Guizhou, Hubei, Jiangxi, northwestern Guangxi, northern Guangdong, western Zhejiang, southern Anhui and southern Henan. As of February, 2008, 12, 2 1 provinces (autonomous regions, municipalities and corps) in China were affected by freezing rain, snow and ice disasters to varying degrees, resulting in 107 deaths, 8 missing, and 15 12000 emergency. The affected area of crops was 65.438+0.77 billion mu, and the harvest was 2530 mu. The damaged forest area is nearly 260 million mu; 354,000 houses collapsed; Causing direct economic losses of RMB111100 million yuan.

What is the weather cause of this snowstorm? The main reason for the formation of a large-scale rain and snow weather process is the abnormal atmospheric circulation, especially the abnormal flow of Eurasian balloon.

As we all know, the atmospheric circulation has its own operating rules, and it maintains a stable circulation state for a certain period of time. There is a low-value system in the southwest of Qinghai-Tibet Plateau, while Siberia maintains a relatively high-value system, namely, meteorological low-pressure system and high-pressure system. These two systems have existed in these two areas for a long time, and the low-pressure system has brought abundant precipitation to the southern part of China, mainly in the southern sea and the Indian Ocean. Cold high pressure from Siberia pushes cold air to the south. Obviously, under normal circumstances, cold air from Siberia is the main controlling factor in winter, which makes most parts of China dry and cold.

On June 5438+ 10, 2008, the warm and humid air flow in the southwest affected most parts of China, while the high-pressure system in the north was stable, and the cold air was continuously transported from Siberia to the south, so the cold and warm air met in the middle and lower reaches of the Yangtze River and the south. The density of cold air is relatively high, and warm air will slide upward along the cold air layer, so the rich water vapor carried by warm and humid airflow will condense, forming rain and snow weather. Due to the unusually long-term intersection of cold and warm air in this area, the rainy and snowy weather in southern China lasts for a long time.

In fact, the three rain and snow weather processes in the south are mainly the three strengthening of the warm and humid airflow in the southwest, and three relatively large rain and snow weather processes have appeared accordingly.

Among them, the third large-scale continuous rain and snow weather process on June 26, 27 and 28, 2008 was strong, and the impact of the previous two times caused the most serious losses.