Seasonal Climate Outlook

Summary

The Department of Primary Industries and Regional Development’s (DPIRD) Statistical Seasonal Forecast (SSF) outlook for October to December, 2019 is indicating 20-60% chance of exceeding median rainfall for the South West land Division (SWLD).

  • For October to December 2019, the SSF is indicating less than 40% chance of exceeding median rainfall for parts of the Central West, Lower West and South West and Great Southern Districts. Neutral (40-60%) chances, elsewhere. The most probable decile range is decile 2-3 parts of the Central West, Lower West and South West and Great Southern Districts and decile 4-7 for elsewhere. See Bureau of Meteorology forecast districts. Predictive skill based on September conditions is poor to good (50 -70% consistent).
  • The Bureau of Meteorology’s current seasonal outlook is indicating 20-30% chance of exceeding median rainfall for October to December 2019, for the South West Land Division. Predictive skill is moderate (55-65% consistent).
  • Temperature outlooks for October to December 2019, from the Bureau indicate over 80% chances of above average day-time maxima for the SWLD. Skill is very good at over 75% consistent. Minimum temperature outlooks indicate a 60-80% chance of above average night-time minima for the SWLD, with very good skill of over 75% consistent.
  • September rainfall, was below average for the SWLD. September maximum temperatures were very much above average, with highest on record in some locations and minimum temperatures were above average.
  • The positive Indian Ocean Dipole (IOD) is forecast to continue until the end of spring.

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 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 October to December 2019, the SSF is indicating less than 40% chance of exceeding median rainfall for parts of the Central West, Lower West and South West and Great Southern Districts. Neutral (40-60%) chances, elsewhere. The most probable decile range is decile 2-3 parts of the Central West, Lower West and South West and Great Southern Districts and decile 4-7 for elsewhere. Predictive skill based on September conditions is poor to good (50 -70% consistent).

SSF forecast of the probability of exceeding median rainfall for October to December using data up to and including September. Indicating 20-60% chance of the majority of the Southwest Land Division receiving above median rainfall.
SSF forecast of the probability of exceeding median rainfall for October to December using data up to and including September.
Percent Consistent skill of the SSF at forecasting October to December rainfall using data up to and including September. Skill is 50 to 70 percent consistent.
Percent Consistent skill of the SSF at forecasting October to December rainfall using data up to and including September.