The track can be divided into four weather regions, ordained mostly by the Andes mountains, and partially by the coastal mountains in Brazil. From west to east these are:
1) the Pacific coast of Peru and Chile
2) the mountains and altiplano of Bolivia
3) the Gran Chaco, Paraguay and Argentina
4) the hills and mountains of southeast Brazil.
In the southern hemisphere, winds blow clockwise around lows and counter-clockwise around highs. The massive ramparts of the Andes deflect the winds from their usual direction and turn them into the many valleys and ridges of the mountains. Each valley comes with its own winds, sometimes enhancing or retarding the larger pattern. This wind flow is important to eclipse observers, especially those willing to take a chance in the rugged terrain. Winds that flow uphill increase the chances of cloudiness. Those that blow downhill warm and dry the air, dissipating any cloud that may be present.