Since the flood season, the precipitation in Liaoning is the highest in the past 30 years. Why are extreme weather frequent?

Since the flood season, Liaoning has experienced extreme precipitation weather. The average precipitation in the whole province reaches 4 17.8 mm, which is the second highest precipitation in the same period in history since 195 1, 70% more than in previous years. The total amount of summer precipitation is also the highest in the same period in the past 30 years. At present, according to the data, the average precipitation in summer can reach 32 days, 10 days more than the same period last year, and the most since 195 1. There were 13 rounds of heavy rain in the whole summer, and the precipitation in western Liaoning exceeded the total precipitation in the whole year, which was the highest in history. Because of the increase of precipitation, the impact on local residents is also the greatest, especially the waterlogged crops in the city are destroyed. In view of this situation, the relevant departments also said that this is due to the persistence of La Nina events in the equatorial Middle East Pacific, which led to abnormal atmospheric circulation in the middle and high latitudes and strong cold vortex in the northeast. However, due to the subtropical high in the northwest Pacific Ocean, the northern boundary is relatively northward, which leads to water vapor transportation, sufficient rainfall and frequent intersection of cold and warm air, resulting in extreme precipitation weather in Liaoning since the flood season.

The precipitation in Liaoning has entered a multi-stage, that is, the influence of SST anomaly on precipitation in Liaoning. Because the extratropical cyclone brought by the previous typhoon has been moving northward, it has increased the circulation of water and gas transportation, and at the same time, the precipitation is unusually high. Then there will be a heavy rainfall process, accompanied by strong convective weather. Due to the continuous precipitation, the risk of disaster prevention will increase. The prevention of floods in small and medium-sized rivers and waterlogging in urban and rural areas should be adversely affected by strong convective weather. For the severely affected areas, people have also been urgently transferred. Relevant departments also said that they should always pay attention to the weather forecast and avoid going to dangerous areas. Strong convective weather reduces outdoor activities to ensure our life safety.