Japan's weather bureau said on Monday that the possibility of an El Nino pattern forming this winter is higher than the 50 per cent it projected in its previous monthly forecast.
Normal weather patterns may continue through winter, but there is a higher chance of an El Nino, the bureau said.
The El Nino - a warming of sea-surface temperatures in the Pacific - can trigger drought in Southeast Asia and Australia and floods in South America, hitting production of key foods such as rice, wheat and sugar.