Summary
The Department of Primary Industries and Regional Development’s (DPIRD) Statistical Seasonal Forecast (SSF) outlook for August to October is generally neutral (40-60%) chance of exceeding median rainfall for the majority of the South West Land Division (SWLD), with areas of less than 40% and higher odds (greater than 60%) for parts of the Great Southern and South Coastal forecast districts.
- For August to October, the SSF is generally neutral (40-60%) chance of exceeding median rainfall for the majority of the South West Land Division, with areas of less than 40% and higher odds (greater than 60%) for parts of the Great Southern and South Coastal forecast districts. The most probable rainfall decile map indicates decile 4-7 for the majority of the SWLD, with decile 2-3 for some parts and decile 8-9 for parts of the Great Southern and South Coastal forecast districts. Predictive skill based on July conditions is poor to moderate (50-75% consistent).
- The Bureau of Meteorology’s current seasonal outlook is indicating close to neutral chances 45-55% of exceeding median rainfall for August to October 2020 for the majority of the South West Land Division. Lower chances 35-40% for areas of the South West, South Coastal and Great Southern Districts and higher chances 60-70% for the Central West District. Predictive skill is poor to good (50-75% consistent). The longer-term outlook for September to November is generally neutral at 45-65% chance. Predictive skill is 50-75% consistent.
- Temperature outlooks for August to October 2020, from the Bureau indicate a 50-70% chance of above average day-time maxima (skill 55-75%) and 45-75% chance of above average night-time minima (skill mostly poor below 55%, but good (55-75%) in the north and southeast).
- July rainfall was generally below average in the SWLD, and above average in parts of the South West and Esperance shire.July maximum temperatures were very much above average. July minimum temperatures were average to above average.
- Higher than normal Mean Sea Level Pressure (MSLP) over the south west and a positive Southern Annual Mode (SAM) are currently the most dominant climate influences, reducing the number of fronts reaching the South West Land Division, in the early part of August.Heavy rain in the south was from a cut off low.
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 August to October, the SSF is generally neutral (40-60%) chance of exceeding median rainfall for the majority of the South West Land Division, with areas of less than 40% and higher odds (greater than 60%) for parts of the Great Southern and South Coastal forecast districts. The most probable rainfall decile map indicates decile 4-7 for the majority of the SWLD, with decile 2-3 for some parts and decile 8-9 for parts of the Great Southern and South Coastal forecast districts. Predictive skill based on July conditions is poor to moderate (50-75% consistent).
