Why does the east coast of New Caledonia receive more rainfall than the west coast?

The east coast of New Caledonia receives significantly more rainfall than the west coast primarily due to the island's topography and the influence of prevailing trade winds.12

The island features a double chain of central mountains that act as a physical barrier to the moisture-laden trade winds, which blow predominantly from the northeast to the southeast. As these winds encounter the mountains, they are forced to rise, causing the air to cool and condense, which results in heavy precipitation on the windward (east) side of the island.12

Consequently, the east coast experiences high annual rainfall—often exceeding 120 inches (3,000 mm)—which supports the growth of forests. In contrast, the west coast lies in the rain shadow of the central mountains, receiving significantly less precipitation (regularly less than 40 inches, or 1,000 mm) and is characterized by savannas.12