A member of the Bureau of Meteorology's agricultural program said there is an overemphasis on major climate drivers such as El Nino in the Pacific Ocean when people are making their assessments of long-term forecast models.
Claire Yeo, who has been working on the BOM's Agri-Climate Outlook program, funded by the Grains Research and Development Corporation (GRDC) said recent commentary around long-term forecasts in many circles had focused squarely on the onset of El Nino and the threat of severe drought.
"We need to get away from this overwhelming focus on climate drivers such as El Nino or the Indian Ocean Dipole and look at them as part of the forecast, rather than the forecast itself," Dr Yeo told the crowd at last week's GRDC update in Bendigo.
"They are a very important part of predicting weather long-term but we need to move past the headlines that El Nino means a catastrophic drought or a La Nina automatically will lead to flooding, it swings the odds in favour of wetter or drier than average weather but it does not guarantee that."
Dr Yeo, who has over 20 years experience as a meteorologist, said last year had been a prime example of how difficult it was to make accurate long term forecasts with dynamic, hard to predict weather events making a big difference on seasonal rainfall.
"We saw in late December one complex weather system that was not showing up in BOM's ACCESS-S model that was being picked up by other models."
"That rain alone delivered 25-50mm over much of central-western Victoria and over 100mm in some parts, which was enough to push long-term rainfalls to above average in its own right, so with one weather event you have a marked change."
"It highlights why the climate drivers should be used in terms of assessing probability, rather than the definitive outlook on their own, weather is so complex and difficult to predict."
"Within our project we are working to try to improve the grains industry's understanding of long-term forecasts which in turn will positively impact farm management decisions."
Dr Yeo's comments regarding the over-emphasis on climate drivers were backed up by Birchip Cropping Group (BCG) researcher Kate Finger.
Speaking at BCG's trials review day last Friday Ms Finger, who is involved in BCG's climate variability projects, said historical data showed a correlation in the Victorian Mallee between El Nino and drier than average conditions but it was far from absolute.
"We surveyed the El Nino years since records began and there were a good proportion that were dry, but there were also average seasons and even a couple of years of above average seasons, it gives a probability but it does not mean anything is set in stone."
Dr Yeo said the BOM was working on a better link between its short term and long term forecasts and to better convey messaging regarding weather.
"Within our ag team we have worked to produce videos that help provide the industry with a comprehensive risk assessment for weather and climate decision making."
"That allows us to be a little more dynamic in helping bridge the gap between the Bureau's short-term and long-term forecasts."
Gregor Heard
Gregor Heard is ACM's national grains industry reporter, based in Horsham, Victoria. He has a wealth of knowledge surrounding the cropping sector through his 15 years in the role. Prior to that he was with the Fairfax network as a reporter with Stock & Land. Some of the major issues he has reported on during his time with the company include the deregulation of the export wheat market, the introduction of genetically modified crops and the fight to protect growers better from grain trader insolvencies. Still involved with the family farm he is passionate about rural Australia and its people and hopes to use his role to act as an advocate for those involved in the grain sector.
Gregor Heard is ACM's national grains industry reporter, based in Horsham, Victoria. He has a wealth of knowledge surrounding the cropping sector through his 15 years in the role. Prior to that he was with the Fairfax network as a reporter with Stock & Land. Some of the major issues he has reported on during his time with the company include the deregulation of the export wheat market, the introduction of genetically modified crops and the fight to protect growers better from grain trader insolvencies. Still involved with the family farm he is passionate about rural Australia and its people and hopes to use his role to act as an advocate for those involved in the grain sector.
