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–S2). It is a dynamical (physics-based) forecast modelling system and is a collaboration between the Bureau of Meteorology and the United Kingdom Meteorological Office.

The Bureau of Meteorology’s seasonal outlook for autumn, March to May 2023, is indicating 25-40% chance of exceeding median rainfall for the SWLD, with mostly poor skill (45-65%).  The current longer-term outlook (at time of writing) for April to June 2023 is 25-45% chance of exceeding median rainfall with mostly poor skill (45-75%). Temperature outlooks for autumn, March to May 2023, from the Bureau indicate an 80% chance of above average day-time maxima. Skill is moderate to good 65-100%. For night-time minima for the SWLD, the Bureau is indicating 70-80% chance of exceeding above average temperatures, with the higher chances along the coast. Skill is mostly poor at 45-65%.

Rainfall outlook for March to May 2023 for Western Australia from the Bureau of Meteorology indicating 25-45% chance of above median rainfall for the SWLD.
Rainfall outlook for March to May 2023 for Western Australia from the Bureau of Meteorology
Percent Consistent skill of the Bureau of Meteorology’s outlook for March to May indicating 50 to 65 percent consistent skill over the SWLD.
Percent Consistent skill of the Bureau of Meteorology’s outlook for March to May.

Looking at other rainfall forecasting models, the majority of models are indicating low chances of exceeding median rainfall for the SWLD for autumn, March to May 2023.

Model distribution summary of 12 models outlook for autumn, March to May 2023, rainfall in the South West Land Division. The majority are indicating below normal chances of exceeding median rainfall for the next three months.
Model distribution summary of 12 models outlook for autumn, March to May 2023, rainfall in the South West Land Division.