What is the first visible sign of a tropical cyclone or hurricane?

The first visible sign of a tropical cyclone or hurricane is typically the formation of bands of clouds. These cloud bands are an indication of organized convection, where moist air is rising and creating cloud formations, which are characteristic of a developing tropical system.

These cloud bands can be observed surrounding the center or eye of the tropical cyclone and are the initial visual indicators of the organized weather system. The presence of these bands means that there is significant convection and wind circulation developing in the atmosphere, contributing to the formation of a tropical cyclone.

While swell, thunder, lightning, and wind gusts can accompany tropical cyclones, they usually occur after the initial signs of organized convection have been established. Swell, for instance, can be generated by strong winds over larger areas as the cyclone strengthens but is not a direct visible sign of the cyclone's initial formation.