24/09/2026
After being accused of being too hard on BOM’s Seasonal Rainfall Forecast in the past, over recent weeks we’ve crunched a lot of data to check if we were right…
Not opinion here, but lots of facts…
The first figure displays the BOM’s spring rainfall forecast at the end of August. Yes, there is a super El Niño, but they forecast pretty much a normal chance of exceeding median rainfall for much of northern NSW and southern QLD and a grim outlook for southern states, including WA….
Yet, WA in the past has hardly been impacted by El Niño events?
In the 2nd figure is the historical track record of the BOM’s spring rainfall forecast at the end of August.
It does approach statistical significance, but it explains less than 20% of the spring rainfall, with no significant result for most of VIC, TAS, SA and WA.
Thus, all farmers apart from southern QLD and northern NSW can ignore their forecast. It has no accuracy for you. None, zip, zero. Facts….
In the next post, we’ll look at a different model to predict spring rainfall.