The Nadi Weather Office says a shallow low-pressure system lies along a trough to the northeast of Fiji, which is gradually moving south towards the country.
They say it is expected to be located to the south of Fiji from later tomorrow, where it will direct a moist north-westerly wind flow over the country, bringing with it heavy rain and thunderstorms.
They add that another trough of low pressure, with cloud and rain, lies slow-moving over the southern parts of the group.
People can expect flash flooding in flood-prone and low-lying informal settlements, communities, business areas, and Irish crossings, leading to traffic disruptions.
Surface flooding is also possible on streets in urban areas with poor drainage.
Drivers are advised to expect slippery roads and reduced visibility, especially during heavy downpours, which increase the risk of road accidents.
