Is there a connection between extreme weather and frequent weather in many countries in the northern hemisphere？

　　Beijing, Jan. 6 (Reporter Zhang Ni) Recently, the strongest rain and snow weather process occurred in central and eastern China since winter, and the daily precipitation in some areas even exceeded the local monthly extreme. What is the cause of this round of "strongest snowfall"? Are there any related factors with the extreme weather encountered by many countries in the northern hemisphere? On the above issues, the reporter of Zhongxin. com recently interviewed experts from the meteorological department.

　　567,000 people were affected by the "strongest snowfall"

　　At the beginning of the new year, China suffered the "strongest snowfall" in winter. From 2 nd to 4 th, the strongest rain and snow weather process occurred in the central and eastern regions since winter.

　　According to the introduction of the Central Meteorological Observatory, this round of rain and snow covered an area of about 4.2 million square kilometers and snow covered an area of about 1.1 million square kilometers. In addition, the daily precipitation of 120 counties (cities) in China has exceeded the local monthly extreme value.

　　The heavy snowfall in recent days has also affected people’s production and life.

　　According to the news from the website of the Ministry of Civil Affairs, heavy snowfall has damaged some houses, facilities, agriculture and power infrastructure in Jiangsu, Anhui, Henan, Hubei, Shaanxi and other provinces, frozen strawberries, vegetables and other crops, and blocked the travel of people and vehicles in some areas.

　　Affected by rain and snow and road icing, many expressways in Shaanxi, Hubei, Anhui, Jiangsu and other provinces are closed, and almost all expressways in Henan Province are closed; Some trains stopped running, and there was a large area delay at the airport.

　　As of 9: 00 on January 5th, 567,000 people in 78 counties (cities, districts) in 27 cities in the above five provinces were affected, resulting in a direct economic loss of 510 million yuan.

　　A new round of snowfall has arrived, and the blizzard warning has sounded again.

　　After a short pause in the "strongest snowfall" process, a new round of snowfall struck again.

　　The forecast of the Central Meteorological Observatory shows that there will be a new round of obvious snowfall in the eastern part of northwest China, most of North China, Huanghuai, Jianghan and other places from the night of the 5 th to the 7 th. Some of the above areas have moderate to heavy snow and local snowstorms (the daily snowfall is 10 ~ 15 mm).

　　Specifically, from 20: 00 on the 5 th to 20: 00 on the 6 th, there was strong snowfall in Shaanxi, Henan and other places, and there were heavy rains in parts of southern China. There is moderate to heavy snow in southeastern Gansu, most of Shaanxi, south-central Shanxi, most of Henan, and northwestern Hubei; There are moderate to heavy rains and local heavy rains in south-central Jiangnan and north-central South China.

　　From 20: 00 on the 6 th to 20: 00 on the 7 th, strong snowfall moved eastward to the south of Huanghuai, and heavy rainfall continued in the south of the Yangtze River. In addition, from the night of the 7 th to the 8 th, there was moderate to heavy snow in parts of the central and eastern parts of Northeast China. In response to a new round of snowfall, the Central Meteorological Observatory issued a blue warning of blizzard at 18: 00 on the 5th.

　　Many countries in the northern hemisphere have recently encountered extreme weather.

　　In addition to China, recently, North America, Europe and other regions have also been hit by extreme weather such as blizzard.

　　According to foreign media reports, the powerful "bomb cyclone" hit the eastern United States on January 4, local time. In some parts of NSW, 18 inches of snow fell, nearly 3,000 households were cut off, and more than 1,000 flights were cancelled. Strong winds and snow caused low visibility, and road traffic was once on the verge of paralysis. The governor of the state declared a state of emergency on January 4. In North America, Canada has also experienced extremely cold weather.

　　In addition, since December, extreme weather such as snowstorms and storms have also ravaged many countries in Europe. For example, last month, Britain experienced the heaviest snowfall in four years, and the airports in Birmingham, the second largest city, and Luton Airport in London were once closed to clear the runway snow, which led to great chaos in air traffic.

　　Recently, the storm "Eleanor" has invaded many European countries, and some areas have been seriously affected by storms and heavy rain and snow.

　　On January 3, Xi ‘an ushered in the first snowfall of this year. The flying snowflakes made the whole ancient city "wrapped in silver", and the local people enjoyed the beautiful snow scene. Photo by Wang Xiaokai

　　Is there a correlation between extreme rain and snow in many countries?

　　Song Wenling, an expert from the Climate Prediction Office of the National Climate Center, analyzed the specific causes of the strongest rain and snow weather in China recently.

　　Song Wenling said that the warm and humid air flow from the Bay of Bengal is very strong recently. The warm and humid air enters China from the southwest and meets the weak cold air from the north to the south in the above areas. The continuous wet and cold state promotes the formation of large-scale rain and snow weather in the central and eastern regions, and the daily snowfall in some areas exceeds the local monthly extreme.

　　Judging from the time period, on average, the cold air is active in January, and if there is plenty of water vapor, it is prone to rain and snow.

　　Then, is there any correlation between the recent snowstorm and extremely cold weather in many countries in the northern hemisphere?

　　Song Wenling explained that generally speaking, the influence system of winter rain and snow weather in different parts of the northern hemisphere has strong regional characteristics.

　　"The weather systems that affect China are mainly members of the East Asian winter monsoon, such as the Siberian high, the western Pacific subtropical high, the southern branch trough, etc. The activities of these systems are mainly concentrated in Asia. On the other hand, the atmospheric movement is not isolated. For example, the difference in the position of the polar vortex center in the northern hemisphere will have different effects on Asia or Europe and the United States. " Song Wenling said. (End)