A tropical depression east of the Solomon Islands is expected to develop into a cyclone in the next six to 18 hours and track towards Fiji.
A gale alert is in place for parts of Fiji and storm force winds are expected to start Tuesday.
Fiji Meteorological Service forecaster Sefo Caravouvinaka said the worst weather is expected over Fiji tomorrow and Wednesday.
Caravouvinaka said it is expected to reach category three strength, with average wind speeds surpassing 119 kilometres per hour.
"As it moves towards Fiji, we expect the system to to intensify into a category system by midday Tuesday," he said.
Authorities are advising people to listen to advisories and stay away from flood prone areas.
The Fiji National Disaster Management Office (NDMO) is already reporting several bridges and crossings are inaccessible.
"The [NDMO] continues to call on the general public to stay away and refrain from attempting to cross flooded roads, rivers, bridges, crossings or walkways‼"
The Fiji Roads Authority is warning that the "heavy rain can lead to fallen trees, obstructing roads and footpath" and is calling on people to "please stay vigilant".
Fiji Police assistant Commissioner - Operations Livai Driu is pleading the public to "remain on high alert".
Driu said people in need of assistance can call their respective divisional police command centres or divisional police commanders.
Fiji Police Force has activated its divisional standby team and is advising parents and guardians supervise children at all times.
Police is also asking motorists "not to take any risks" in trying to cross flooded roads.
'Secure schools'
The education minister Aseri Radrodro is urging parents and guardians "to exercise all precautions".
In a statement released on Facebook, Radrodro has called on divisional and education officers to ensure the safety and security of all schools.
"Given the heavy rain and strong winds being experienced, may I request that education officers liaise closely with respective heads of schools to ensure we secure all schools, facilities and ensure the safety of our children especially those in boarding facilities," he said.
He said the education ministry, with other relevant authorities, is monitoring the situation.
"Should it be confirmed that a cyclone will be hitting Fiji, all external exams are likely to be shifted to a later date. This announcement should be coming out later today."
He said that the priority right now is safety of lives.
RNZ
