Seasonal Climate Outlook

Recent climate

October rainfall was below average to average for the SWLD. October maximum and minimum temperatures were above average. The 2019 growing season rainfall (May to October) was generally below average (decile 2-3) for the SWLD. 

Rainfall decile map for 1 May to 31 October 2019 for the South West Land Division.

In October, the atmospheric pressure was slightly above normal over the SWLD.

Indian Ocean sea surface temperatures  off the WA coastline have been cooler than average. The November 2019 and January 2020, SST forecast by the Bureau of Meteorology indicates SSTs are likely to be warming up north of WA.

The Southern Annular Mode (SAM), also known as the Antarctic Oscillation (AAO), describes the north–south movement of the westerly wind belt that circles Antarctica, dominating the middle to higher latitudes of the southern hemisphere.  SAM has been negative since July and is forecast to remain negative during November.  A neagative SAM increases the chance of spring heatwaves occurring across southern Australia. 

The strong positive Indian Ocean Dipole (IOD) continues. A positive IOD generally means below average spring rainfall for much of the central and southern Australia, and warmer than average daytime temperatures for the southern two thirds of Australia. IOD events typically have little influence on Australian climate from December to April, however, given that this positive IOD is so strong, it is likely to take several weeks to decline, and could persist well into mid-summer. The El Niño–Southern Oscillation (ENSO) is expected to remain neutral for the remainder of 2019. For further information, see the Bureau of Meteorology’s ENSO Wrap Up.

The table below gives a summary of past month and three-month South West Land Division (SWLD) climate conditions, and can indicate what is likely to occur in the near future if climate conditions follow the current pattern.