Tropical Cyclone Mal has intensified to a category two storm, according to the Fiji Meteorological Service
The weather office said the cyclone is expected to pass close to the west of Fiji on Tuesday night local time, with the centre likely to lay approximately 170km west of Nadi at 3am Wednesday, local time.
It may begin to have an impact on Yasawa and Mamanuca from later on Tuesday.
Forecaster Samisoni Waqavakatoga said the system is expected to reach the high end of category two at its peak strength, but potentially could reach category three with average winds surpassing 119 kilometres per hour.
"There is a possibility it could reach category three but for now, like I said, we've just been maintaining it at the high end of category two, we're not jumping any guns here but if the environment is still favourable it could reach category three status," Waqavakatoga said.
The meteorological office says a a flash flood warning remains in force for the low-lying areas in Qauia, Lami, Marata Village, Wailoku.
A flash flood alert remains in force for low-lying areas of, Coral Coast to Navua, Lami, Suva, Nausori, Tailevu, Naitasiri, Ovalau.
Fiji National Disaster Management Office is advising people follow official advisories and remain alert.
All schools are closed on Tuesday and Wednesday and public servants have been instructed to work from home.
The education ministry has deferred final external exams for Year 12 and 13 to next week.
Education Minister Aseri Radrodro said the decision has been made as some students, teachers, and examination supervisors may not be able to access their schools in the aftermath of the cyclone.
Assitant police commissioner operations ACP Livai Driu is "calling for the strict supervision of children stressing, this is not the time for children to be playing outdoors or swimming".
The Fiji Roads Authority is also advising people to be vigilant and stay away from flood-prone areas