Why does the "heavy rain" in the forecasters of Beijing Meteorological Observatory analysis and forecast become "light rain"

Yesterday, many citizens' beds first cared about the rain. According to the notification of the Municipal Meteorological Observatory, small rain weather appears in the city. The huge "heavy rain" in the forecast is that the "light rain" is only "light rain". What is going on?

After waiting for a day of rainfall, on the evening of June 26, the rainfall came first from the mountains and southern parts, and the rainfall in most areas did not come after night. Lei Lei, the chief forecaster of the Municipal Meteorological Observatory, introduced that the precipitation gradually influenced the city from south to north. As of 11:00 yesterday, small rain weather appeared in the city, rain in the west and south, heavy rain and lightning with lightning.

Why did the heavy rain and territorial heavy rain in the forecast last only a light rain in the end?

Lei Lei said that the precipitation process is smaller than the forecast. The reason for the retrospective is that the low vortex system that causes rainfall has great uncertainty when it first discovered. The north, so it will have a significant impact on Beijing, but in the end its movement path is south and east, and the strong rainfall landed in the central and southern parts of Hebei and Shandong. "

Lei Lei told reporters that the low vortex system is like a typhoon at sea. The movement path has very large uncertainty, especially this large -scale low vortex system. As long as the path deviation is tens of kilometers, the rain belt will deviate a lot. For Beijing, rainfall will be significantly reduced, and more extreme situations will become very weak. And if the path of the system moves is a little bit north, Beijing's rainfall will be much larger.

Generally speaking, this weather system has a common impact on July and August. After entering the main flood season, the subtropical high voltage is obviously lifted north. In addition, there will be obvious weather system coordination in the periphery, and large -scale rainfall will occur. However, in late June, the weather that was obviously affected by the low vortex in the southwest and the south was not common in Beijing. In the same period, there were basically no similar weather systems to refer to. After carrying out multiple rounds of discussions and tracking with the Central Meteorological Observatory and North China regions, coupled with the previous numerical forecast conclusions to grasp the north of the system, judging that the low vortex system will cause significant rainfall to Beijing.

Lei Lei explained that once the rainfall in the summer, once there is a convection in the flow, the local area is more difficult to grasp. In the forecast of a large -scale system in the low vortex system, the scope of the rain belt will not have much deviation, just like this rainfall will appear in Shandong, Hebei, Beijing, Tianjin and other places, but the specific area will be heavy in the rain. Where is the falling area of ​​the precipitation, which has a lot to do with the path and location of the system movement. It becomes difficult.

On June 26, there were heavy rainstorms in Shandong. The 24 -hour rainfall of Shandong Single Station reached 372 millimeters, and the hourly rainfall at the single station in the central and southern parts of Hebei also reached 110 millimeters. Lei Lei said that Beijing was not too high on June 26, with a large amount of clouds and weak energy. Therefore, the local convection weather did not develop, which also caused the precipitation to be less obvious.

Judging from the current forecast, three days from this day, Beijing's high altitude is still under the influence of the cold vortex system. There are more clouds at different times, and there will be short -term thunder showers or showers. This week, the weather is mainly cloudy, with the highest temperature of about 29 ° C, but the humidity is relatively large, and the body sensation is sultry. Pay attention to heatstroke prevention and cooling. (Source: Beijing Daily)

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