Australian wheat exports jumped in December after late plantings and weather difficulties dragged November shipments down but rail and port closures due to floods in January may cause another dip in exports.

Exports in December from the world's fourth-largest wheat exporter totalled 1.28 million tonnes, up from 914,200 tonnes in November and also up on the 1.08 million tonnes a year ago, according to data from Australian Bureau of Statistics.

In the 12 months to December, wheat exports from Australia totalled 14.6 million tonnes but quality problems in the 2010/11 marketing year and weather related transport difficulties could pressure export figures in the months ahead.

Australia's government forecaster ABARES sees this year's wheat harvest at 26.8 million tonnes but extensive rains during the harvest period lowered quality, and some analysts predict that as much as 10 million tonnes will be downgraded to feed quality.