Recent warming of the Pacific Ocean may signal an El Nino weather event is forming, the Australian Bureau of Meteorology said on Tuesday.
Climate models indicate the central tropical Pacific Ocean is likely to continue to warm, with El Nino thresholds to be reached or exceeded by mid-year, the weather bureau said.
"There is about a 50 per cent chance of El Nino developing in the coming months, which is twice the normal likelihood," the bureau said.
Should an El Nino eventuate, the system would likely bring below-average winter and spring rainfall over eastern Australia and above-average daytime temperatures over the southern half of Australia.
Such climatic conditions would prove a blow for Australian wheat production, which is reliant on rains in winter and spring.
Wheat production is expected to total 24.39 million tonnes in the 2015/16 season starting July 1, Australia's chief commodity forecaster said this month, up 3 per cent from this year's 23.61 million tonnes.
Wheat production from Australia's east coast has suffered two consecutive seasons of poor production as dry weather curbed yields.
Another season of poor wheat production from Australian east coast farmers will also extend the headwinds for GrainCorp Ltd , the country's largest bulk grain handler.
GrainCorp said in February its 2015 full-year earnings are expected to hit a five-year low as drought along the east coast curbs grain production.