Australia's Port Hedland, which handles about a fifth of the world's seaborne-traded iron ore, will reopen on Wednesday after being spared the brunt of a cyclone that has also shut other major ports in Western Australia.
Category 1 Cyclone Peta -- the weakest on a scale of one-to-five -- forced Port Hedland, Cape Lambert and Dampier ports to shut down on Tuesday, halting almost half of the world's iron ore trade.
The storm is forecast to make landfall by 1300 GMT and weaken, according to the Australian Bureau of Meteorology.
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"Conditions have improved in the last few hours with swell, sea and wind reducing to a level that shipping operations can restart," the Port Hedland Port Authority said.
"Consequently the port and anchorage will reopen at 1600 today (0800 GMT)."
Global miner Rio Tinto, which ships more than 200 million tons of iron ore through Dampier and Cape Lambert, said it expected to reopen the ports on Thursday.
"Based on the current outlook, we would expect most coastal operations to resume tomorrow morning," Rio Tinto said.
"The resumption of ship-loading at Cape Lambert and Dampier will depend on prevailing sea conditions, and no decision has been taken yet," it added.
Iron ore prices have gained support from concerns that Australia's cyclone season, which runs from November until April, will reduce supplies.
Miners said it was too early to assess Cyclone Peta's impact on shipments, as iron ore freighters typically take 24 to 36 hours to load.
Weather models indicate Cyclone Peta may go back over the ocean after it makes landfall, but it is not expected to intensify.
Most of the iron ore mined in Australia is contracted by Chinese steel mills, with Japanese and South Korean mills also big buyers.
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Total iron ore shipments from Port Hedland in December reached a monthly record 26 million tons.
The region between Port Hedland and Dampier is known among mariners as "cyclone alley", with at least half a dozen cyclones hitting from November to April each season.