As the cold and warm air masses intertwined to form an extratropical cyclone, the northeastern region of my country affected by the cyclone became one of the national rainfall centers in the past 24 hours. Heavy to heavy rain fell in many places in Liaoning Province, southeastern Inner Mongolia, and Jilin. Previously, the extratropical cyclone had already reached North China. The Huanghuai River shed a lot of rain, and many places in Shandong experienced widespread heavy rainfall, which reversed the earlier situation of less rainfall in many places in the Huanghuai River in North China. Today, the cyclone continues to move northward and gradually weakens in intensity.
1. Partially approaching 40 degrees in the south
In fact, judging from monitoring data, as extratropical cyclones roar across the north, the plum rain situation in southern my country has changed - the heavy rain belt in the south has begun to shift westward, with more water vapor The heavy rains in Hubei, Hunan, Jiangxi and other places, which were once very fierce before, have significantly weakened, and many places along the southeastern coast have even begun to clear up on a large scale today. In contrast, the rainfall in Sichuan and Shaanxi increased significantly today, with a large area of heavy rain appearing in front of Longmen Mountain.
The reason why the heavy rain situation in the south has changed significantly is related to the strengthening of the subtropical high pressure-the summer of 2024 is coming fiercely. With the obvious strengthening of the subtropical high pressure, the temperature in the southeastern coastal areas of my country has risen rapidly. On July 2, the temperature in Xianju and Qingtian, Zhejiang exceeded 38 degrees, while Fuzhou also ushered in a high temperature day. In the next few days, the subtropical high pressure center will firmly occupy the southeastern coastal areas, and Fujian and Zhejiang provinces will become the "base camp" of high temperatures in the south.
Monitoring data shows that Zhejiang and Fujian have become the national high temperature center today on July 3. As of 20:00, the two provinces have completely monopolized the top ten high temperature rankings. Among them, Lishui, Zhejiang, with 39.2 degrees, and Sanming, Fujian, with 38.5 degrees, are the highest in the two provinces, and Lishui is the highest in the two provinces. It is approaching the 40 degree mark in a big way.
In the provincial capital municipalities directly under the Central Government, 38.1 degrees Celsius in Fuzhou, 37 degrees Celsius in Hangzhou, and 36.3 degrees Celsius in Xujiahui, Shanghai hit new highs this year. Nanchang recorded the first local high temperature day this year with 35.3 degrees Celsius. So far, among the low-altitude provincial capital cities in the south, Guangzhou, Chengdu and Changsha are still left. There has been no high temperature. As the subtropical high further strengthens tomorrow, Fujian and Zhejiang provinces are likely to experience the first 40-degree temperature this year tomorrow.
2. Continuous high temperatures in Jiangsu, Zhejiang and Shanghai start
The subtropical high is an important system that affects summer weather. The downdraft it brings will suppress the formation of clouds, making the sky clear and cloudless, and the sun will shine directly on the ground, causing the temperature to rise rapidly. On July 3, 2024, the subtropical high pressure strengthened significantly, which immediately and directly caused high temperature weather along the southeastern coast of my country.
Zhejiang, Shanghai and other provinces and cities have previously announced that plum blossoms will appear on July 4. After the plum rain season ends, Jiangsu, Zhejiang and Shanghai have entered a typical midsummer season. Due to the strong control of the subtropical high, the rain belt moves northward, and high temperature weather occurs frequently during this period. For example, the current forecast shows that the temperature in Hangzhou, Zhejiang will be very stable, and there seems to be no end in sight to the high temperature weather of 37 to 38 degrees in the future.
High temperature weather under subtropical high pressure is often accompanied by high humidity, making the human body feel even hotter. This hot and humid weather is not only uncomfortable, but also affects outdoor activities and agricultural production. Currently, under the subtropical high pressure, temperatures in many places in Fujian, Zhejiang, and Shanghai are rising and they are beginning to become typical examples of hot and humid weather. The water vapor content in the air is high and the evaporation process is slow, causing the perceived temperature to be higher than the actual temperature.
Does this mean that this summer will continue to be hot like this? The situation may not be that simple. Multiple meteorological agencies and numerical forecasts show that after July 10, the subtropical high pressure has a tendency to retreat southward or even collapse. The main rain belt may return to the middle and lower reaches of the Yangtze River. The high temperatures in Jiangsu, Zhejiang and Shanghai may weaken in the middle of the year.
Although the current influence of the subtropical high is strong, forecasts show that it may retreat southward or even collapse after July 10. If this trend comes true, the main rain belt may return to the middle and lower reaches of the Yangtze River, and the high temperature weather in Jiangsu, Zhejiang and Shanghai will be alleviated. By then, precipitation in the south will increase and temperatures will drop, but we still need to be wary of the intermittent recurrence of high temperatures and humidity.
