Typhoon Candu is approaching the coast of Jiangsu, Zhejiang and Shanghai. Where will enter the "dangerous semicircle" to undertake the strongest typhoon storm?

The right side of the typhoon direction is often the place where the maximum wind speed appears, which is called "dangerous semicircle". Typhoon is a circular system rotating counterclockwise. For China, when a typhoon comes or lands, the "Northeast Quadrant" located at the upper right is the area with the strongest wind and rain and the most serious impact. From the beginning of the "Candu" seven-level wind circle that affects the land to before landing, the right side of the direction of travel is the influence area of the dangerous semicircle.

Central and northern Zhejiang and the Yangtze River Delta, including Shanghai and southern Jiangsu, may enter the typhoon "dangerous semicircle" and become the rainstorm center tomorrow and the day after tomorrow. There is still uncertainty about when Candu will land or pass through Zhejiang, which will directly affect the wind and rain intensity in the Yangtze River Delta region.

relevant information

The formation of typhoon requires the following conditions: the sea surface water temperature is above 26.5℃; Initial disturbance of a positive vorticity; The shear of ambient wind in the vertical direction is very small; Low pressure or cloud disturbance is at least several latitudes from the equator. Because people don't fully understand the formation of typhoons now, the above list is only a necessary condition for the formation of typhoons.

The initial stage of typhoon is tropical depression, and it usually takes about 2 days from the initial low-pressure circulation to the maximum average wind force near the center, only three or four days for the slow one and only a few hours for the fast one. In the development stage, the typhoon continuously absorbs energy until the central air pressure reaches the lowest value and the wind speed reaches the maximum value. After the typhoon landed, under the joint influence of ground friction and insufficient energy supply, it will quickly weaken the death.