High Quality Content by WIKIPEDIA articles! Mexico tropical cyclone rainfall climatology discusses precipitation characteristics of tropical cyclones that have struck Mexico over the years. One-third of the annual rainfall received along the Mexican Riviera and up to half of the rainfall received in Baja California Sur is directly attributable to tropical cyclones moving up the west coast of Mexico. The central plateau is shielded from the high rainfall amounts seen on the oceanward slopes of the Sierra Madre Oriental and Occidental mountain chains.