People are urged to remain vigilant and prepare, as the effects of Tropical Depression TD03F are expected to be felt from tomorrow night, as the centre of the system is expected to enter the Fiji waters on Tuesday.
TD03F continues to move slowly over open waters between the Solomon Islands and the far north of Vanuatu, with the system forecast to track southeastward between Fiji and Vanuatu over the next few days.
The Nadi Weather Office says TD03F is expected to enter the Fiji waters on Tuesday and exit through the Lau Group by Wednesday.
They say an associated active trough of low pressure is already affecting the country, bringing overcast conditions and occasional rain.
The Weather Office has stressed that persistent heavy rain could lead to flash flooding.
Rain is forecast to become more frequent from Tuesday as TD03F approaches Fiji from the west, gradually spreading across the rest of the country until Wednesday.
This will further increase the risk of flooding in low-lying and flood-prone areas, including downstream of major rivers, along small streams, and possibly across major river systems nationwide.
The Weather Office says strong winds are also expected, with northwest to northeast winds averaging around 50 kilometres per hour, and gusts of up to 70 kilometres per hour.
These conditions are likely to affect the northern and western parts of Viti Levu and Vanua Levu, as well as the Yasawa and Mamanuca Groups, and parts of the northern Lau and Lomaiviti Groups from Tuesday through Wednesday.
For mariners, the forecast for all Fiji waters includes northeast winds of 15 to 20 knots, moderate to rough seas, and poor visibility in areas of heavy rain and thunderstorms. From Tuesday, winds may strengthen to 30 knots with gusts of up to 40 knots across all Fiji waters until Wednesday.
Possible impacts include poor visibility for drivers due to heavy rain, isolated to significant damage to houses built of old or light corrugated iron or timber, flash flooding or major flooding in low-lying communities, and disruptions to traffic at Irish crossings.
Flooding on major roads could also impact essential services and power supply.
Weather conditions are expected to improve from Thursday.
People are advised to remain alert, follow official weather updates, and take all necessary precautions during this period.