By RNZ. RNZ’s news is shared with Kaniva by arrangement.

The Tonga Meteorological Service is warning people in the kingdom to be vigilant as it forecasts Tropical Cyclone Sarai to reach Tongatapu this afternoon.

Formerly a category two system, the cyclone has now been downgraded to category one, although it is still generating sustained winds of 85km/h with gusts reaching up to 120km/h.

Sarai’s centre is expected to be about 15km west of Nuku’alofa at 1pm local time today.

The storm is moving east southeast at 12km/h.

Authorities in Tonga are urging all islands to be prepared as the cyclone’s track could change at any moment and mariners are strongly advised not to venture out to sea especially in smaller fishing boats.

“They said the track of this tropical cyclone is uncertain so we have prepared the whole of the island groups, get ready and prepared for this cyclone,” Tonga National Emergency Management Committee chief executive Paula Ma’u said.

Meanwhile, flights to Tonga have been disrupted by the approaching cyclone in Nuku’alofa with many returning family members and visitors travelling from the United States and Australia via Fiji stranded in Nadi.

A direct flight from Australia that was supposed to have arrived on Sunday was also suspended with the airline saying it would not be considering rescheduling it for 48 hours.

Authorities estimate about 300 incoming and outgoing travellers have been affected by the cancellations.