While ex-tropical cyclone Alfred deposited some useful falls west of the Great Dividing Range in NSW in general farmers and agronomists in the region are having to to alter strategies based on the assumption of heavy early autumn rains.

"We know that storm driven rain can be patchy, but given the forecasts were predicting 100mm plus along with flood warnings we thought we were fairly likely to get at least 50mm," said Moree-based Delta Ag agronomist Rob Long.

"There have been patches, such as around Warialda and through parts of the northern tablelands where there have been good falls of 50-70mm and that could spur the planting of early lines of winter crops including canola, faba beans and wheat but broadly in a line west of Pallamallawa and Croppa Creek it has been very disappointing," Mr Long said.

"Given the forecast we thought that was fairly low risk but with most areas only getting around 10-15mm over a few days it will be just enough to get the urea to melt and incorporate in the top few centimetres of the soil, we'd certainly have liked to have seen some more to completely minimise that volatilisation risk."

Veteran agricultural consultant Bob Freebairn, Coonabarabran, said it was difficult for farmers to assess forecasts for storm-driven rain, but said in his region there were relatively low risk forage crops, such as oats and triticale that could be planted early.

"There is always the risk of hot weather killing the crops, but in general I've found that they will handle a burst of hot weather and come through, so it means your reward is probably higher than your risk," Mr Freebairn said.

"It would be difficult to justify planting your entire crop on the basis of the forecasts given the extreme variability in the forecast and how localised storm-driven rain can be, but if you're looking to generate some early feed before the weather cools off then it is probably a different story."

"We looked like we'd missed out, then on the night we were not supposed to get much we ended up getting 36mm, but you can see variations from one end of the farm to the other with this sort of rain, it's making general planning more difficult."

"We'd have liked to have seen the storm put a bit more moisture in the profile, it's far from empty after good rain in November / December, but it's only around 50-70pc full, so we'd ideally like to see more during what are traditionally the wetter months in this part of the world."