Summary
The Department of Primary Industries and Regional Development’s (DPIRD) Statistical Seasonal Forecast (SSF) outlook for January to March 2021 is indicating neutral (40-60%) chance of exceeding median rainfall for the majority of the South West Land Division.
- For January to March 2021, the SSF is indicating neutral (40-60%) chance of exceeding median rainfall for the majority of the South West Land Division (SWLD). With higher chances (60-80%) for the Central West forecast District, eastern parts of the Central Wheatbelt and along the south coast. The most probable rainfall decile map indicates decile 8-10 for the Central West District and along the south coast, and decile 4-7 elsewhere in the SWLD. Predictive skill based on December conditions is mostly poor to moderate (50-75% consistent).
- The Bureau of Meteorology’s seasonal outlook for January to March 2021 indicated 65-75% of exceeding median rainfall for the majority of the SWLD. Predictive skill is moderate to good (55-75% consistent). The current outlook for February to April and longer-term outlook for March to May is for neutral to wetter conditions. Predictive skill is moderate (50-65%).
- Temperature outlooks for February to April 2021, from the Bureau indicate a 70-80% chance of above average day-time maxima along the coast, with lower chances (50%) for interior (skill 50-75%) and 70-80% chance of above average night-time minima (skill 55-75%) for the SWLD.
- December rainfall was generally below average for the South West Land Division. December maximum temperatures were above average and minimum temperatures were generally average.
- The La Niña in the tropical Pacific Ocean, together with a positive SAM are currently the main climate drivers influencing SWLD climate. In a La Niña, there is an increased chance of above average number of tropical systems (cyclones and lows) across northern Australia. This may lead to more summer rainfall in the SWLD. A positive SAM means westerly winds are further south than normal and this may increase temperatures in the SWLD.
Three month Outlook for the South West Land Division
Statistical Seasonal Forecasting (SSF)
DPIRD’s Statistical Seasonal Forecast (SSF) system uses historical relationships between global sea surface temperature and sea level pressure with rainfall in south-west Australia to produce forecasts of rainfall for the coming months. Users can click on any station indicated on the map for location-specific forecast information from the Seasonal Climate Information web page.
For January to March 2021, the SSF is indicating neutral (40-60%) chance of exceeding median rainfall for the majority of the South West Land Division (SWLD). With higher chances (60-80%) for the Central West forecast District, eastern parts of the Central Wheatbelt and along the south coast. The most probable rainfall decile map indicates decile 8-10 for the Central West District and along the south coast, and decile 4-7 elsewhere in the SWLD. Predictive skill based on December conditions is mostly poor to moderate (50-75% consistent).
