Why do typhoons follow the edge of the subtropical high?

The south side of the high will be affected by the subtropical monsoon and the intertropical convergence zone, and typhoons will follow the edge of the subtropical high. The driving force of typhoon movement includes both the internal force generated by the rotation of the typhoon itself (when the surrounding guided airflow is weak, the typhoon's own internal force will make the typhoon slowly move northwest), and the influence of the edge guided airflow of the surrounding weather system. external force (for example, when the typhoon is at the southern edge of the stable subtropical high, it is guided by the easterly airflow from the south of the high pressure to move to the west. After entering the westerly belt, it is affected by the southwesterly winds from the edge of the westerly belt and the northwest edge of the subtropical high and moves to the northeast).

In comparison, the effect of external forces is much greater than the effect of internal forces. Therefore, typhoons with generally stable paths and most complex paths are guided by external forces. Only when the guiding effects of multiple external forces cancel each other out or simply When there is no external force to guide the typhoon, the typhoon will slowly move northward due to the influence of internal force.