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 seasonal outlook issued on the 29 October indicated a 50-80% of exceeding median rainfall for November 2020 to January 2021 for the majority of the South West Land Division. Predictive skill is poor to good (45-75% consistent). The longer-term outlook for December 2020  to February 2021 gives higher chances at 70-80%. Predictive skill is moderate to good (55-75%).

Temperature outlooks for November to January 2021, from the Bureau indicate a 65-80% chance of above average day-time maxima along the west coast, with lower chances (30-60%) for the south coast and interior (high skill 75-100%) and 80% chance of above average night-time minima (high skill 65-100%) for the SWLD. These outlooks can be found at http://www.bom.gov.au/climate/ahead/outlooks/archive/20201029-outlook.shtml .

Rainfall outlook for November 2020 to January 2021 for Western Australia from the Bureau of Meteorology, indicating high chance of above median rainfall for the SWLD.
Rainfall outlook for November 2020 to January 2021 for Western Australia from the Bureau of Meteorology.
Percent Consistent skill of the Bureau of Meteorology’s outlook for November 2020 to January 2021 indicating 45 to 75 percent consistent skill over the SWLD.
Percent Consistent skill of the Bureau of Meteorology’s outlook for November 2020  to January 2021. 

Looking at other rainfall forecasting models, the majority are indicating above chances of exceeding median rainfall for November to January 2021 for the SWLD.

Model distribution summary of 13 models (not including the SSF) which forecast November 2020 to January 2021 rainfall in the South West Land Division. Majority of models are indicating higher chances of exceeding median rainfall.
Model distribution summary of 13 models (not including the SSF) which forecast November 2020 to January 2021 rainfall in the South West Land Division.