Seasonal outlook (Jun-Sep)

The BOM continues to forecast a warmer and drier than normal winter across much of Australia's grain belt. Rainfall is expected to be below average across southern, central and eastern Australia, including much of the Murray-Darling Basin, with some areas facing an elevated risk of unusually dry conditions. Temperatures are forecast to be above average across most cropping regions, with warmer days and nights likely through winter. The ENSO is currently neutral, but there are increasing signs of El Niño developing during winter, while a positive Indian Ocean Dipole remains a possibility later in winter and spring. Both climate drivers are typically associated with reduced rainfall across eastern and southern Australia, although confidence in the strength and timing of these events remains low.

We are getting plenty of El Nino warning signs but lots of these are coming from the forecast of a significant warming in the mid Pacific. The SOI (Southern Oscillation Index – air pressure difference between Tahiti & Darwin) has plunged from +15 in March to -15 currently (30-day ave). Typically, when the SOI goes strong negative (-10 and below) trade winds weaken, Indonesian thunderstorms diminish and moisture transport into Australia declines. However, it’s been still raining in Australia and Indonesian convection remains active, albeit patchy. There are warning signs of El Nino in the trade winds with persistent westerly anomalies, but this still isn’t conclusive. The ocean is already in strong El Niño mode, but the atmosphere hasn't fully committed yet! That's a better situation than if both Niño and SOI were already behaving like 1982, 1997 or 2015. But if Niño gets into +2.0 to +2.5°C territory and stays there, history suggests the atmosphere will follow eventually. The bottom line is it’s the mix of these key El Nino measures, and not just one in isolation which will be key in confirming the likely progression into El Nino.

We hope this simple summary clears up the weather pattern and forecasts. We AG Scientia for explaining it to a humble grain trader!