According to the National Climate Center, under the background of La Niña this year, cold air has frequently affected our country six times since April, resulting in extreme cooling events in many places.

Although the average temperature in my country since April has been the sixth highest in the same period since 1961, due to the large temperature fluctuations, especially in the Beijing-Tianjin-Hebei region, which has been the center of cooling many times, the temperature fluctuation is the second largest in the same period since 1961. , the characteristics of cold and warm fluctuations are particularly prominent, giving people the feeling that this spring is particularly "cold".

  1. Since April this year, my country's temperature has fluctuated frequently, especially in Beijing, Tianjin and Hebei.

  Since April 2022, the national average temperature has been 13.2°C, 0.8°C higher than the same period of the previous year, the sixth highest in the same period since 1961, and consistent with the global warming trend.

In April, the temperature fluctuated frequently, and experienced three obvious fluctuations of warm and cold.

The national average temperature is low from March 31 to April 2, high from April 3 to 14, low from 15 to 19, high again from 20 to 26, and low from April 27 to May 2 , May 3-10 on the high side.

The daily variation characteristics of the national average maximum temperature are basically the same as the average temperature, reflecting three fluctuations of cold and warm, but the maximum temperature has a larger fluctuation range.

  Since April, the average temperature in the Beijing-Tianjin-Hebei region has been 15.5°C, 0.5°C higher than the same period of the previous year; during this period, the daily average temperature was the lowest (8.5°C, April 1) and the highest (23.9°C, May 4 The standard deviation of the average temperature (the degree of deviation from the average condition) is 4.5°C, which is 1.5°C higher than the same period of the normal year (3.0°C), the second largest since 1961, second only to 4.7°C in 1965. , indicating that the temperature varies greatly; the standard deviation of the average maximum temperature in the Beijing-Tianjin-Hebei region is 5.6 °C, which is also the second largest in the same period since 1961.

  Since April, a total of 44 national meteorological stations across the country have experienced extreme daily cooling events, of which the daily temperature drop in Lulong, Hebei (12.1°C) has broken the historical extreme value; the daily minimum temperature of 91 national meteorological stations has exceeded the monthly minimum value, of which 74 stations Happened in early May.

In addition, a total of 15 national meteorological stations across the country had the highest daily temperature exceeding the monthly maximum. In early May, the highest daily temperature at 7 stations including Foping (38.1°C) in Shaanxi, Lingwu (36.2°C) in Ningxia, and Lanzhou (35.3°C) in Gansu exceeded the maximum value. Spring maximum.

 2. Frequent cold air activities have a wide range of influences

  Spring is in the adjustment period of atmospheric circulation, and the activities of cold and warm air are frequent.

Since the spring of this year, 11 times of cold air have affected our country, and 4 of them have reached the level of cold wave.

Especially since April, a total of 6 cold air events have affected my country, of which 3 consecutive cold air events have reached the cold wave standard since late April (April 22-23, April 27-30 and May 6-8). Japan), it is rare to experience 3 cold waves in 2 weeks.

The number of cold air processes and cold wave processes was 1.9 and 2.2 more than that of the same period of the previous year, which were tied for the third and second most since 1961 (the maximum number of cold wave processes in 1969 was 4).

  From April 27th to 30th this year, affected by the nationwide cold wave process, the temperature in southern Xinjiang, northeastern and central parts of Inner Mongolia, eastern Ningxia, northern Shaanxi, eastern and southern Liaoning, southern Hebei, and northern Henan generally fell by 12~ 16°C, and locally above 16°C.

  From May 6th to 8th, affected by the cold wave process, the temperature in Northeast China, North China, central Inner Mongolia, and northern Shandong ranged from 8 to 14°C, and the temperature in central Northeast China, western Liaoning, northeastern Hebei, and central and eastern Inner Mongolia exceeded 14°C.

The national land area with a process cooling rate of more than 8°C reached 1.604 million square kilometers.

  3. The main reasons for the large fluctuations of cold and warm in the central and eastern parts of my country

  The recent large fluctuation of cold and warm temperatures in the central and eastern parts of my country is not a feature of the low global average temperature under the influence of the Tonga volcano, but is mainly affected by the periodic fluctuations of the atmospheric circulation and tropical SST anomalies.

  First, there have been frequent cold air (cold waves) processes since April, especially three consecutive cold waves since late April.

In the late spring and early summer seasons, the precipitation in most parts of the central and eastern regions is relatively low, and the temperature recovers quickly during the intermittent period of cold air.

  Second, frequent cold air activities are closely related to the periodic fluctuations of the westerly circulation in the Eurasian mid-high latitudes. The Ural Mountains blocking high pressure and the East Asian trough intensify periodically, triggering three cold wave weather processes.

  The third is the continued impact of the La Niña event.

Under the La Niña background, the Eurasian mid-high latitude circulation has large meridional degrees and obvious periodic fluctuations, which provides favorable climatic background conditions for the frequent influence of cold air on my country.

  4. Forecast and forecast of recent weather and climate trends

  According to the forecast of the Central Meteorological Observatory, it is expected that in the next 10 days (May 14-23), the average temperature in most parts of the South will be lower than the same period of the year, and the temperature in Jianghan, Jianghuai, Jiangnan, South China, Henan, Guizhou and other places will be 2-4 ℃, the temperature in most of the north is close to the same period of the year to high.

After the 23rd, the temperature in the south will gradually rise.

  The National Climate Center predicts that from May 28 to June 11, except for Yunnan, western Guangxi, Hainan and other places where the temperature is lower than the same period of the year, the temperature in most of the rest of the country is close to the same period of the year to higher, among which the central and western Inner Mongolia, Northwestern Liaoning, northern Hebei, Shandong, eastern Henan, northern Jiangsu, northern Anhui, northern Xinjiang, Tibet and other places are 1-2 °C higher.

As the season progresses, attention should be paid to the effects of high temperatures starting in June.

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