Affected by the 11th typhoon "Haikui" this year
Heavy rainfall occurs in Fujian
It shows that the heavy rainfall has a wide range, strong intensity
(Data map)
Long duration and large accumulated rainfall
As of September 6
Fuzhou (urban area, Yongtai, Changle)
Daily precipitation breaks the local historical record
There are short duration precipitation records in many places
Or the daily precipitation record in September was broken
What is the reason for this?
Why is there still heavy rain in the south today?
When will the precipitation end?
Look at the interpretation of Fujian Meteorological Station
Why does it cause precipitation in many places
Record breaking?
First, the typhoon "dangerous semicircle" is prominent. Although the typhoon "Haikui" landed in Dongshan County, Zhangzhou City, these extreme areas are within the "dangerous semicircle" of the typhoon. What is "dangerous semicircle"? Typhoon is a circular system rotating counterclockwise, which is generally on the right side of the typhoon's heading direction, and is called "dangerous semicircle". For China, when the typhoon arrives or lands, the "Northeast Quadrant" at the top right is the area with the strongest wind and rain and the most serious impact.
Second, the typhoon moved slowly. Although the typhoon "Haikui" after landing was weak, its guiding air flow was weak, making it move slowly, which happened to "encounter" the weak cold air going south. The southeast air flow with abundant water vapor on the north side of the typhoon center interacted with the weak cold air, and under the effect of terrain uplift, it triggered a long and strong rainstorm cloud cluster, This rainstorm cloud cluster formed a "train effect" under the organization and guidance of the southeast air flow, and constantly passed over the central coastal area of Fujian Province, resulting in heavy rainfall with strong intensity, long duration, wide range and high disaster risk.
Why is there still heavy rain in the south today?
The main reason is that the residual vortex circulation of typhoon "Haikui" is located in Guangdong, and the convection lasts for a long time. In addition, the low-level northeast wind converges with the southeast wind, and the humidity condition is good. However, because the wind speed is weakened, the wind shear in southern Fujian is weak, and the circulation center moves to the west, the precipitation intensity will be significantly weakened compared with the heavy rain in Fuzhou on the night of the 5th.
When will the precipitation end?
Today, the scope of heavy rain in Fujian is significantly reduced, mainly concentrated in the southern region. The heavy rain will start tomorrow and end, but there will still be showers in some areas.
Reminder from meteorologist
Today, there are heavy rains in some areas of Zhangzhou and Longyan, among which there are heavy rains in some towns of Zhangzhou. The risk level of rainstorm disasters is high. We should pay attention to preventing the possible mountain torrents, floods in small and medium-sized basins, urban and rural waterlogging, landslides, mud rock flows and other secondary disasters caused by heavy rainfall.
Science popularization time
Source: Fujian Meteorology
Editor: Xiao Ran
