Why is the weather always good before a typhoon?

There is a strong updraft near the center of the typhoon, but after so much air goes up, it will eventually come down, so the airflow will spread out after reaching high altitude, and then sink back to the ground around the typhoon. Therefore, before the typhoon, it was controlled by the peripheral descending airflow, and the weather was sunny and often very hot. Also related to air pressure, downward flow corresponds to high pressure ~