Australia’s Bureau of Meteorology confirms La Nina is here

The Australian Bureau of Meteorology raised its El Nino Southern Oscillation outlook to La Nina Tuesday, acknowledging that temperature readings confirm that the widely-anticipated weather phenomenon is underway.

Typically associated with prolonged dry spells through the key South American and parts of the US Midwest corn and soy regions, La Nina arrives at a time when weather worries are already providing support for soybeans as fears mount over the lack of rain, particularly in Argentina, and its impact on planting through the tail end of 2017.

In order for 2017–18 to be classed as a La Nina year, the event needs to last for at least 3 months.

However, the bureau's models suggest that the impact will be weak and short-lived, likely to persist until the Southern Hemisphere’s autumn – essentially the second quarter of 2018.

"Climate models surveyed by the Bureau suggest that while this event is likely to persist over the southern summer, it will be weaker than the strong La Nina of 2010–12," the bureau said.

Soybeans surged 30% from $13/bu to $17/bu from the middle of 2010 through the middle of 2012.

While La Nina brings dryness to Argentina and the US Midwest, it can also bring wetter weather in the Pacific equatorial region, and more rain across Brazil, Australia and Southeast Asia and parts of Sub-Saharan Africa, embracing some significant agricultural production powerhouses.

Australia sits just to the south of the key Pacific equatorial region that defines the development of the La Nina or El Nino weather pattern – as such, Australia’s Bureau of Meteorology plays a key role in monitoring the water temperatures and other symptoms that denote the pattern developing.

A similar weak La Nina event developed last year at around the same time with minimal impact on the soybean, corn or wheat markets.