As Tropical Cyclone Keni moves closer to Fiji's Viti Levu and the country's southern islands it has been upgraded to a category two storm.
Keni is moving eastsoutheast at 12 knots and is continuing to intensify.
Currently sustained winds close to its centre are blowing at 100 kilometres an hour.
Keni Tracking Map 8pm Monday Photo: Fiji Met Office
The Fiji Met Service is predicting the storm will come within about 120 kilometres of Nadi by midday Tuesday and about 100 kilometres of the southern island of Kadavu later in the afternoon.
Met Service Director, Ravindra Kumar, says the impact across much of Viti Levu and the southern islands will be dramatic with about 150 millimetres of rain expected over a 24 hour period, with resulting flooding.
He says storm force winds can also be expected.
Meanwhile Tonga disaster officials have called for people to be on alert with Keni posing a threat for the south of Tonga by Wednesday.