Summary
The Department of Primary Industries and Regional Development’s (DPIRD) Statistical Seasonal Forecast (SSF) outlook for October to December 2021 is indicating neutral chances (40-60%) of exceeding median rainfall for the majority of the South West Land Division (SWLD).
- For October to December, the SSF is indicating neutral chances (40-60%) exceeding median rainfall for the majority of the South West Land Division (SWLD). Lower chances (less than 40%) for the northern part of the Central West forecast district and higher chances (60-70%) for parts of the Central wheatbelt and South West forecast districts. The most probable rainfall decile map indicates decile 4-7 for the majority of SWLD. Predictive skill based on September conditions is mostly poor to moderate (50-70% consistent).
- The Bureau of Meteorology’s seasonal outlook for October to December 2021 is indicating 45-75% chance of above median rainfall for the SWLD, with the higher chances for areas of the Great Southern, South Coastal and South East Coastal forecast districts. Predictive skill is poor to moderate (45-65% consistent). The longer term outlook for November 2021 to January 2021 is similar. Skill is poor to good (45-75%).
- Temperature outlooks for October to December 2021, from the Bureau indicate a 25-65% chance of above average day-time maxima, with lower chances for the southern coast and interior (skill 75-100%). The Bureau indicates a 50-80% chance of exceeding above average night-time minima for the SWLD, with higher chances for the Central West forecast district (skill 75-100%).
- September rainfall was below average to average for the SWLD. September maximum temperatures were average to above average and minimum temperatures were below average to average, with some frost damage reported.
- The main climate driver influencing the SWLD is warmer than normal Sea Surface Temperatures in the Indian Ocean following the weakened Indian Ocean Dipole, favouring above average rainfall for parts of Australia.
Three month outlook for the south-west of Western Australia
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 rainfall forecasts for the coming months. Users can click on any weather station indicated on the map for location-specific forecast information from DPIRD’s Seasonal Climate Information pages.
For October to December, the SSF is indicating neutral chances (40-60%) exceeding median rainfall for the majority of the South West Land Division (SWLD). Lower chances (less than 40%) for the northern part of the Central West forecast district and higher chances (60-70%) for parts of the Central wheatbelt and South West forecast districts. The most probable rainfall decile map indicates decile 4-7 for the majority of SWLD. Predictive skill based on September conditions is mostly poor to moderate (50-70% consistent).
