Is it true that 20 17 this year is a hundred-year cold wave? How is the cold wave formed?

There is a cold wave every winter. Last year's cold wave was called the century cold wave. This year's forecast may be a once-in-a-century cold wave. The cold wave is the result of a contest between air and air pressure. The formation of the cold wave is harmful, but the premise is that the intensity of the cold wave cannot be too high. Judging from the current national temperature, the intensity of cold wave is obviously strengthening gradually. I wonder what the cold wave will do this year.

Is it true that 20 17 this year is a hundred-year cold wave?

The Heilongjiang Meteorological Observatory 10/0/710: 20 on October 9 issued a yellow warning signal for the cold wave in Yichun, Hegang and Jiamusi: it is predicted that the minimum temperature in the above areas will drop by more than 10℃ in the next 24 hours. Suihua, Harbin, Daqing, Shuangyashan, Jixi, Qitaihe and Mudanjiang issued cold wave blue warning signals: It is estimated that the minimum temperature in these areas will drop by more than 8℃ in the next 48 hours. At the same time, there are 4-5 northwest winds and 6 gusts. Please take precautions.

Is it true that 20 17 this year is a hundred-year cold wave? How is the cold wave formed?

From the second half of 20 16, China began to issue early warning signals of the Han Dynasty. From last year 1 1, the strongest cold air began to affect Xinjiang in the second half of this year, and will sweep across most parts of China from west to east on February 2, 65438, with strong intensity and wide influence range. According to Li Xiaoquan, a meteorologist, the impact of this cold air is mainly cooling and strong wind, which is very widespread and will affect the south of South China.

Affected by cold air, the temperature in the northern region will drop by 6- 10℃, the highest temperature in Beijing will fall below 0℃, and the lowest temperature in the middle and lower reaches of the Yangtze River will drop to freezing point. At the same time, the northern region will encounter 4-6 winds, and the maximum wind force in Xinjiang wind area can reach 10- 12. In addition, with the vigorous cleaning of cold air and north wind, the fog and haze weather in North China, Huanghuai and other places will gradually weaken or dissipate from north to south, and the air will obviously improve. In early June, there will be many cold air activities in May 438+February, and the temperature in most parts of the country will turn from warm to cold.

From February 20 16 to February 20 17, China will encounter a cold winter. Reason: La Nina will break out this summer. La Nina event, the opposite phenomenon of El Nino, is an abnormal decrease of sea surface temperature in the cold water area of equatorial Pacific.

Is it true that 20 17 this year is a hundred-year cold wave? How is the cold wave formed?

Will La Nina definitely lead to a cold winter? Li Xiaoquan said that under normal circumstances, when La Nina occurs, the winter in China will be colder, but it does not mean that it will enter the cold winter, but the probability of entering the cold winter is higher, especially in the southern region. "La Nina came last year, which will make winter cold, but it doesn't mean it will be particularly cold. It can be seen that some years have entered the cold winter, which is mostly related to the La Nina phenomenon, but it is not that La Nina will definitely enter the cold winter. " As it said, El Nino turned to La Nina in the winter of 1998/ 1999, but China experienced a warm winter. China Weather Network reported on September 22nd that the equatorial Middle East Pacific has entered the La Nina state, but it has not reached the La Nina event standard. China Meteorological Bureau will continuously monitor the development of La Nina.

2016-2017126 October, a two-day national conference on climate trend prediction was held in Beijing. The meeting focused on forecasting and discussing the national temperature and precipitation from the winter of 20 16 to the spring of 20 17.

Is it true that 20 17 this year is a hundred-year cold wave? How is the cold wave formed?

The meeting discussed and analyzed the characteristics of sea surface temperature, snow cover, polar ice and land surface anomalies and their possible impacts on Eurasian atmospheric circulation and China's climate, and predicted the future evolution of atmospheric circulation and the abnormal trend of temperature and precipitation in winter and spring in China, especially the intensity of cold air activity in winter and spring, the drought occurrence area, and the period and region where staged strong cooling and freezing rain and snow occurred.

In August this year, the SST anomaly index in the equatorial Middle East Pacific reached -0.53℃ and entered La Nina state. If La Nina lasts for more than 5 months, it is judged as La Nina event. Experts believe that although the La Niñ a state or La Niñ a event is prone to low temperature in winter in China, it is not the only factor that affects China's climate. Eurasian snow cover, Arctic sea ice and winter monsoon index are also important factors.