Why is there an "inverted trough" rainstorm so far away from the typhoon?

Ideally, a typhoon is a sphere. But the ideal is full and the reality is skinny. Except for a few super typhoons with very low latitude and small scope, the periphery of most typhoons will become prickly under the influence of other immortals. Sometimes a typhoon will stick out a thorn to the north, which looks like an inverted V shape from the weather map, so it is called "typhoon inverted trough". Here, cold air and warm humidity often meet fiercely, causing heavy rain, the most typical of which is Xiangshui in Yancheng, Jiangsu. In 2000 and 20 12, prapiroon and anemone affected the rainstorm respectively, and the 24-hour rainfall reached 82 1 and 5 1 mm respectively, and the rainfall intensity far exceeded the core precipitation of these two typhoons.