Farmer claims that an incorrect long-term weather forecast published last September triggered roller-coaster livestock market prices in recent months have been dismissed by the Bureau of Meteorology boss.
In a Senate Estimates hearing on Tuesday, BOM director Andrew Johnson said he would be "surprised" if any farmer made a business decision on a single forecast, however he believed subsequent media reporting of that forecast catastrophised the issue.
The comments were made in response to Nationals deputy leader Perin Davey referring to a BOM forecast published on September 21, 2023, that predicted unusually low rainfall in parts of southern and eastern Australia.
However, some farmers were instead surprised by wet conditions instead of the hotter and drier weather associated with an El Nino event that was declared by the BOM.
Senator Davey said it is that forecast that "many people have said really cemented their decisions on what stocking rates to go through over the summer months."
"And then we went on to a very wet October to December and by the 19th of October you were predicting a neutral forecast, by which stage though a lot of farmers had put their stock on the market and changed their stocking cropping rotations because in September that is when you need to do your summer cropping planning," she said.
"Do you accept in any way that that forecast might have led some farmers to make business decisions?"
In response, BOM director Andrew Johnson said "I cannot speculate" on what motivates individual farm businesses to make their decisions.
"Each business has its own unique set of circumstances," Dr Johnson said.
"I would be surprised... that a single forecast would impact a decision that a farm business would make. We update our seasonal forecasts regularly, we all know that there is a degree of uncertainty in those forecasts.
He said that forecasts are "probabilistic" and provide an estimate of the chance of an event exceeding a median value, "they are not deterministic."
"We update that information regularly because the conditions that drive those estimates are continuously changing. Again, I would be very surprised if one forecast influenced the decision of one farm family or one farm business.
"There are many other factors, it had been very dry during the winter, feed prices are high, stocking rates were high, cattle prices were falling they had been falling since January 2022."
LNP Senator for Queensland Gerard Rennick also suggested that the forecast for a "very dry summer" had prompted some farmers to sell their cattle "when they did not need to."
"And they sold those cattle at a loss and now they have to go back and restock on the basis of your forecast," he said.
Despite his protestations, Dr Johnson said the BOM would review its messaging to the public around long-range forecasts.
He said that he realised that almost everything the BOM does has an impact on many Australians in pointing at some of the more accurate forecasts made by the national forecaster in recent times.
Mr Johnson also said the BOM could not be held accountable for forecasts that the media "latches on to" and "what I have observed this summer is a catastrophisation, frankly, of a whole range of weather events."