Multi-week model survey (8-28 days)

The next genuine chance for rain appears to be in the eastern half of NSW mid-October with northern areas coming online at the end of October through to early November. The Niño 4 SST region has finally warmed up. This index has quite a strong correlation with rain in CQ and Gulf areas in November, so it’s plausible to expect November will be more favourable than October.

Model form: the BOM multi-week model continues the ‘blue kiss of death’ with over-exuberant wet forecasts. Since May if this model were remotely close Keepit and Copeton Dams would be overflowing. Seasonal and multi-week models struggle with systems originating in the Tasman Sea and assume a simplistic east-west moisture airflow. The NCEP/GFS continues to jump around and is showing a colourful system with some strength eventuating across NSW mid-Oct. The IRI model is normally super-cautious and rain across NSW this month adds to confidence levels. NT and Ord cropping zones will have to wait for the end of the month, as the air pressure at Darwin has finally moved below zero.