LOCAL farmers have a very nervous wait ahead of them as they prepare crops in the hope of significant rainfall which has been tipped at the end of May - well after the traditional ANZAC Day deadline.
New data released last week by the Bureau of Meteorology gives La Nina nearly a 90 per cent chance of returning this spring, as the ocean continues to cool in the tropical eastern Pacific.
Predictions give La Nina an 80 per cent chance of occurring by late winter/early spring and an 86 per cent chance in late spring and early summer.
Most models suggest that the Pacific Ocean will return to a neutral phase in the next month, despite El Nino having little influence on Australia’s weather recently.
Wangaratta AG Warehouse agronomist Bec Bingley is concerned by the current autumn conditions, saying there are more challenges to face other than a lack of rainfall.
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“I am very nervous about the little rainfall we have had, however, the concerns at the moment is frost damage to newly emerging crops,” Mrs Bingley said.
“Conditions were looking good up until mid-March, but a lack of rainfall since then has raised a lot of questions.
“The long-range forecast models suggest that crop producers will not see substantial rainfall until the end of May.
“Some broadacre producers are in the position where they are changing the variety of seed to suit the current conditions if they are to raise a successful yield this year.
“For example, winter wheat is being changed to spring wheat as the spring variety is quicker to mature and can handle the current conditions when seeding.”
While many international models are hinting at the return of La Nina this year, the Australian model suggests that we will be in neutral ENSO conditions during late winter and early spring.
The large supply of abnormally cool water in the eastern tropical Pacific Ocean does add some weight to the possibility of La Nina returning this year.
However, it is too early to know with much certainty whether this will happen or not.
During the last five years we have seen three consecutive La Nina (2020-2023), and an El Nino, with the possibility for a fourth La Nina in 2024.
This would be the first time this sequence was to occur in the history of Australia's record keeping in 1910.
This seasonal dip in model reliability is called the autumn predictability barrier in the Southern Hemisphere (spring predictability barrier in the Northern Hemisphere) and means the current outlook should be treated with caution.
Ms Bingley said while some farmers are being cautious, other producers have rolled the dice in the hope conditions will swing in their favour.
“Dairy farmers have seeded grass which is at one leaf (just emerged),” Ms Bingley said.
“The concern with this is frost hitting the new growth which can damage the cells of the plant by burning the leaf off and limit overall growth and production.
“Some beef, sheep and cropping producers are holding off because of the lack of rain.
“There is some moisture in the subsoil but the first 10 centimetres is extremely dry.
“Right now everyone needs to take things week by week and use local knowledge and a stroke of luck moving forward.”
In the coming months, the bureau will observe the ocean temperatures in the Pacific and the international climate models closely.
