Twin cyclones are bearing down on Pacific islands, with Fiji’s main island likely to be directly hit by a category five storm for the second time this year. Tonga and Fiji were bracing for potentially catastrophic damage as tropical cyclones Zazu and Yasa intensified off their coastlines on Wednesday. Zazu, which is north-east of Tonga’s capital Nuku’alofa, is rated a category one system, with winds of up to 90km/h (55mph). But Yasa, about 550km (340 miles) north-west of Fiji’s main island Viti Levu, has already been upgraded to a category five cyclone, with winds of up to 270km/h. It is expected to make landfall over Fiji late on Thursday or early on Friday. Yasa is moving slowly, according to Fiji’s meteorological office, at about 8km/h, but gathering in strength. The system is more than 400km across, the acting director of the Nadi weather office, Terry Atalifo, said, and damaging rain and winds are expected for days. Authorities in both Tonga and Fiji have advised residents to prepare for damaging winds and flash floods. Fishing fleets have been ordered back to port. Fiji’s prime minister, Frank Bainimarama, has urged all Fijians to prepare evacuation plans. “We should all prepare now for heavy rain, damaging winds, coastal inundation and flooding across the country,” he said in a national address. Bainimarama said Fijians should board up their homes, prepare emergency supplies and have a route planned to their nearest evacuation centre. The New Zealand-based meteorological service Weatherwatch said the twin cyclones were unlikely to join up but their proximity to one another did complicate forecasting. “It makes it a little tricky to know exactly how close Yasa will get to Fiji – direct hit is the current thinking,” Weatherwatch managing director Philip Duncan said. Duncan said parts of Fiji were forecast to get up to 400mm of rain, and waves of up to 10 metres were predicted off the country’s western coast. “If you’re on a very low-lying island, now is the time to be getting out of there: this is a very serious situation.” The storms are the first to form in the South Pacific’s cyclone season, which runs until May next year. The region was battered by Tropical Cyclone Harold in April, a category five storm that gouged a trail of destruction across the Solomon Islands, Vanuatu, Fiji and Tonga. Such strong cyclones were once rare but have become increasingly common in recent years. Bainimarama, in particular, has been prominent in attributing the increasing regularity and intensity of cyclones to climate change. He said the archipelago nation of about 900,000 people must again prepare for a worst-case scenario, just eight months after it last endured a lashing from a super-storm. “Let’s remember Cyclone Harold – at the last minute it ramped up in strength and ended up being worse than predicted,” he warned. “Do not be caught off guard by this latest storm.” with Agence-France Presse