A tropical cyclone heading for Tonga has been upgraded to a category 4 - a severe storm likely to cause structural damage.
Cyclone Ian has estimated winds of 166km/h at its centre with momentary gusts of over 230km/h, and is expected to hit Tonga this evening.
He says it is projected to pass to the south of the Vava'u island group, between those islands and the Ha'apai group, but could go over Vava'u.
Gale-force winds, thunderstorms and flooding of low-lying coastal areas are expected. Strong wind warnings for the Niuas island group remain in force.