20 1 1 characteristics and causes of freezing weather in Hunan

At present, the freezing disaster in South China has two characteristics. First, freezing rain is dominant, with less snowfall. In 2008, there was not only freezing rain, but also large-scale snowfall. Second, the temperature has fluctuated this year, and the short-term warming is conducive to the melting of ice.

The similarity is that the intensity of cold air is similar to that in 2008, but the water vapor transport conditions of warm and humid airflow in southwest China are different from that of subtropical high in northwest Pacific, which determines that it is unlikely that there will be a large-scale continuous low-temperature rain, snow and freezing disaster like that in 2008 this year.

Chen Lijuan pointed out that in 2008, the subtropical high, one of the main weather systems affecting China, was very strong and located to the west, which not only prevented the cold air from advancing southward, but also made the cold air in the north stagnate in China for a long time, and repeatedly converged with the warm and humid airflow in the south, providing a sufficient source of water vapor for continuous precipitation. Although the cold air is very strong this year, it is often swept away because there is no blocking force.

In addition, in 2008, the warm and humid airflow in the southwest and the water vapor in the northwest Pacific were very abundant, which interacted with cold air and caused disasters. The water vapor condition in the south this year is far worse than that in 2008. "The warm and humid airflow in the southwest is intermittently active, and the cold air is a bit' difficult to sing', which is not easy to cause a wide range of persistent disasters." Chen Lijuan said.