Tropical Cyclone Daman, which is now hitting northwestern Fiji, has intensified into a category four storm, with winds of up to 275 kilometres per hour.
The cyclone is currently northwest of Labasa and expected to pass over the southwestern tip of Vanua Levu tonight.
It has winds of 195 kilometres an hour at its centre with gusts to 275 kilometres an hour.
Forecasters say it will bring widespread flooding and very high seas.
They are encouraging mariners not to go to sea.
Daman is moving east but is expected to go southeast later.