All the climate models now show an El Nino pattern is likely this year, with six of the seven global models predicting the threshold will be reached as early as July.

The Australian Bureau of Meteorology says it's based on warmer temperatures in the Pacific Ocean along the equator.

El Ninos tend to bring hotter and drier weather to eastern Australia.Seventy per cent of the El Nino events in the past century have resulted in drought over Australia, especially when combined with a positive Indian Ocean Dipole, which is also predicted for early spring.

Luke Matthews, agricultural commodity researcher with the Commonwealth Bank, says it's likely to reduce farm output and exports this year, with wheat crops in eastern Australia worst affected.

Since 1970, none of the 11 El Nino events have produced bumper grain crops.

"Specifically for wheat yields across eastern states; what we see is that in eight of 11 of those El Ninos, yields have fallen by at least 15 per cent.

"So there is a significant chance that if we have an El Nino, we'll see disappointing wheat crops across the east coast."

Mr Matthews says it's different for Western and South Australia, where there is no consistent correlation between El Nino and low wheat yields.

He hopes there won't be an El Nino, and remains optimistic that the recent weeks of autumn rain have set up the soil to grow good crops.

Global wheat prices have fallen in the past week, but Mr Matthews says the price is still around $290 a tonne, which is in the high range, with the unrest in the Black Sea region providing a floor to the price.

The US wheat crop is currently rated as a 'very disappointing 34 per cent good to excellent'.Wheat futures have also fallen off a recent high of 725 US cents a bushel to 680 US cents bushel for July delivery.

Source:- abc.net.au