Tropical cyclone in Tonga: El Nino Southern Oscillation hasn’t had a significant impact on the intensity and frequency of the tropical cyclones in this region, but it has modified the location of the genesis of TCs.
Tonga was the spot of the genesis of tropical cyclones, but the El Nino phenomenon shifted it lower.
This impacted Tonga’s islands, causing stronger winds while reaching Tonga’s coast during their upper motions.
However, La Nina also affects the Tonga region, it increases the risks of tropical cyclones’ formation.
Even if the tropical cyclones are formed to the west of Tonga, they’re pushed to the east by the westerlies on the islands. (Source: Science Direct)