On the afternoon of April 22, convection in all parts of the north is everywhere, and sporadic echoes are gradually assembling a strong convective rain belt, with the convective rain belt gradually forming on the evening of April 22 and sweeping through North China, fierce thunderstorms, strong winds, hail, short-term heavy rainfall and other fierce weather swept through Beijing, Tianjin and Hebei, for Beijing and other places, this is the first spring thunder this year.
1. Fierce thunderstorms are coming in the north
According to monitoring data, from yesterday (April 22) night to this morning (April 23), under the influence of the cold vortex, a wide range of precipitation occurred in the central and southern parts of North China and western Liaoning, among which moderate to heavy rain and local heavy rain fell in the Beijing-Tianjin-Hebei region, and the rainfall in 24 hours at Tianjin Xiqing National Station reached 60.2 mm, setting the first rainstorm day of the year, equivalent to four times the sum of the precipitation in the previous four months! Hebei Qian'an, Qinglong, Luanxian, Bazhou, Lulong, Xinji and other places also reached the level of heavy rainfall. In the past, the precipitation in the North China Plain was abnormally low, and today's hearty rain suddenly filled the gap. At present, the rainfall belt is moving eastward, and the north-central part of Shandong and Liaoning will be the next targets of heavy rainfall.
Not only was the rain heavy, but it was also accompanied by strong thunder and lightning activity, making it feel like watching a large-scale electric light show. According to data from the Chinese Academy of Meteorological Sciences, from yesterday night to this morning, a total of nearly 30,000 lightning occurred in the Beijing-Tianjin-Hebei region, of which cloud-to-ground lightning accounted for more than half, and the highest density reached more than 10 times per square kilometer.
Second, the blue cold vortex strikes again!
Spring is the season of rejuvenation, but also the season of changeable weather. Recently, the northern part of the mainland has experienced a rare heavy precipitation process, which has brought a lot of impact on people's lives. Actually, this thunderstorm is a typical cold vortex thunderstorm. Cold vortex refers to a rotating air flow with a lower temperature in the upper altitude, which can carry cold air southward and meet the warm and moist air flow on the ground, forming a strong convective movement, resulting in unstable weather such as thunderstorms. Cold vortex thunderstorms are characterized by small scope, short duration, and sudden occurrence, which often bring a lot of trouble to people.
On the evening of April 22, the center of the cold vortex was located in eastern Inner Mongolia - Russia, and there was a clear high-altitude trough on its south side, along which there was a strong northwest wind to transport cold air to the northern region. At the same time, in the northern part of the continent recently, a relatively warm and humid airflow has been transported to the north, forming a clear temperature and humidity gradient with the cold air, which provides conditions for the occurrence of convection. Against this backdrop, when cold air meets warm and moist airflows, a violent upward motion occurs, forming a large number of cumulonimbus clouds, which can trigger thunderstorms.
3. Authoritative forecast: local cooling exceeds 10 degrees
This thunderstorm not only brought precipitation to the north, but also caused temperatures to plummet, making it feel like a return to early spring. According to the 24-hour temperature change map at 10 o'clock, this morning, under the influence of cold vortex and cold air, there was a cooling of 4~8 degrees in North China, Huanghuai, and Northeast China, and the local temperature in Shandong, Liaoning, and Hebei reached more than 10 degrees.
Moreover, this is not the final blow of the cold vortex, according to the supercomputer forecast3, after the cold vortex weakens eastward, from April 25, there will be a new cold vortex in the westerly wind belt that is poised to move south, and bring a wave of stronger cold air, not only will there be thunderstorms again in the north, but also some areas will face a significant cooling.
For example, in Zhangjiakou, Hebei Province, the official forecast shows that under the offensive of cold air and cold vortex, the temperature in Zhangjiakou will drop again from April 28, and the maximum temperature in Zhangjiakou will drop to below 15 degrees on April 29, and the lowest temperature area is only in single digits, compared with the temperature of 30 degrees in Zhangjiakou on April 26, such a temperature means that there will be a drastic cooling of more than 15 degrees.
In short, this thunderstorm in the north is a strong convective weather caused by a cold vortex, which brings a lot of precipitation to the north and also makes the temperature plummet, which is a typical cold vortex thunderstorm, which often brings a lot of trouble to people. Moreover, the cold vortex is not over yet, it will strike again, bringing stronger cold air to cool the north again. Therefore, friends in the north should pay attention to the weather forecast in time, take preventive measures, and maintain good health.