Seasonal Climate Outlook

Bureau of Meteorology seasonal climate outlook

The Bureau of Meteorology's climate forecast system for monthly and seasonal climate outlooks is the Australian Community Climate Earth-System Simulator – Seasonal (ACCESS–S). It is a dynamical (physics-based) forecast modelling system and is a collaboration between the Bureau of Meteorology and the UK Meteorological Office.

The Bureau of Meteorology’s current seasonal outlook is indicating close to neutral chances (45-60%) of exceeding median rainfall for winter, June to August 2020. Predictive skill is poor to good (45-75% consistent). These probabilties have weakened from outlooks produced in May. The longer-term outlook for July to September, is for higher chances at 55-70% with predictive skill at 50-65% consistent. 

Temperature outlooks for winter, June to August 2020, from the Bureau indicate a 50-65% chance of above average day-time maxima (skill 55-65%) and a 50-70% chance of above average night-time minima (skill 50-65%) for the SWLD.

Rainfall outlook for June to August 2020 for Western Australia from the Bureau of Meteorology, indicating a neutral outlook for the SWLD.
Rainfall outlook for June to August 2020 for Western Australia from the Bureau of Meteorology.
Percent Consistent skill of the Bureau of Meteorology’s outlook for June to August, indicating 45 to 75 percent consistent skill over the SWLD.
Percent Consistent skill of the Bureau of Meteorology’s outlook for June to August.

Looking at other climate model outlooks for winter rainfall over southern WA, the majority have either neutral chances of exceeding median rainfall or only weak shifts towards wetter or drier conditions. 

Model summary for winter rainfall in the South West Land Division, indicating neutral chance.
Model summary for winter rainfall in the South West Land Division.