The latest cyclone advisory for Tonga has cancelled a gale warning for Niuatoputapu in the far north, but the threat to Vava'u remains.
The category three cyclone was about 300 kilometres east north east of Vava'u and a similar distance to the southeast of Niuatoputapu earlier this afternoon.
Winds gusting up to 185 kilometres an hour are expected at the centre of the cyclone.
The prediction from the Tropical Cyclone Warning Centre is that Winston is likely to spin sharply in a reverse direction, increasing in intensity and possibly threatening Vava'u and/ or Ha'apai for a second time.
Meanwhile the cyclone warning remains in place for Niue.
A gale warning has been issued for the island with winds now expected to gust up to 120 kilometres an hour, with sometimes heavy rain and squally thunderstorms.