Tonga: Authorities issue adverse weather warnings as of Dec. 21

Authorities have issued adverse weather warnings for several areas as of Dec. 21. The Tonga Meteorological Services have issued strong wind warnings and small craft advisories for several coastal regions through at least 00:01 Dec. 22. The advisory is in effect for Tongatapu & 'Eua, 'Otu Mu'omu'a, Ha'apai, Vava'u, Niuafo'ou & Niuatoputapu, and Telekitonga & Telekitokelau. Officials could update and possibly extend the coverage of weather alerts over the coming hours.

Winds between 27-56 kph (16-34 mph) are expected in Tongatapu & 'Eua, Ha'apai, Telekitonga & Telekitokelau, and Vava'u, with winds between 27-46 kph (16- 28 mph) forecast in Niuafo'ou & Niuatoputapu. Moderate sea swells of 3 meters (9 feet) are forecast across coastal areas. Additionally, isolated heavy showers are possible.

Hazardous Conditions
Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where heavy rain has saturated the soil.

Authorities could issue mandatory evacuation orders for flood-prone communities. Disruptions to electricity and telecommunications services are possible where significant flooding or landslides impact utility networks.

Transport
Severe weather could also trigger flight delays and cancellations at regional airports. Authorities may temporarily suspend port operations or close beach fronts if strong winds trigger hazardous sea conditions.