Summary
The Department of Primary Industries and Regional Development’s (DPIRD) Statistical Seasonal Forecast (SSF) outlook for winter, June to August, 2022 and June to October 2022 is indicating below 40% probability of above median rainfall for parts of the Central West, Central Wheatbelt, Great Southern, South Coastal and South East Coastal forecast districts, with higher probabilities for the remainder of the South West Land Division.
- For winter, June to August, the SSF forecast is indicating less than 40% probability of above median rainfall in parts of the Central West, Central Wheatbelt, Great Southern, South Coastal and South East Coastal forecast districts. Above 60% for western parts of the Great Southern and South West forecast districts, with neutral probabilities elsewhere. The most likely decile range map is indicating decile 2-3 for large part of the SWLD, decile 8-9 for eastern part of Central West, western part of the Great Southern and the South West forecast districts and decile 4-7 elsewhere. Skill is poor to good at 50 to 75 % consistent.
- The Bureau of Meteorology’s seasonal outlook for winter, June to August, 2022 is indicating less than 40% chance of above median rainfall for the SWLD. Predictive skill is moderate to good (55-100% consistent). The current longer-term outlook (at time of writing) for July to September 2022 has higher chances (45-70%), with moderate to good skill (45-75%).
- Temperature outlooks for winter, June to August 2022, from the Bureau indicate a 45-80% chance of above average day-time maxima, with the higher chances along the coast. Skill is 65-75%. For night-time minima for the SWLD, the Bureau is indicating 45-80% chance of exceeding above average temperatures, with the higher chances along the coast. Skill is poor at 45-65%.
- The SSF forecast for SWLD June to October 2022 rainfall is indicating less than 40% probability of above median rainfall in parts of the Central West, Central Wheatbelt, Great Southern, South Coastal and South East Coastal forecast districts. Above 60% for western parts of the Great Southern and along the southern coast of the South West forecast district, with neutral probabilities elsewhere. The most likely decile range map is indicating decile 2-3 for large part of the SWLD, decile 8-9 for western part of the Great Southern and the South West forecast districts and decile 4-7 elsewhere. Skill is poor to good at 50 to 100 % consistent.
- May rainfall was mostly average for the SWLD. May maximum temperatures were average to above average, with minimum temperatures average.
- The main climate drivers influencing South West Land Division climate is the positive Southern Annular mode, which often has a drying influence. Models are indicating the development of a negative IOD in July and persisting until at least October at this stage. Past negative IOD events generally increase rainfall in the eastern grainbelt. Outlook accuracy begins to significantly improve during June.
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 DPIRD’s Seasonal Climate Information pages.
For winter, June to August, the SSF forecast is indicating less than 40% probability of above median rainfall in parts of the Central West, Central Wheatbelt, Great Southern, South Coastal and South East Coastal forecast districts. Above 60% for western parts of the Great Southern and South West forecast districts, with neutral probabilities elsewhere. The most likely decile range map is indicating decile 2-3 for large part of the SWLD, decile 8-9 for eastern part of Central West, western part of the Great Southern and the South West forecast districts and decile 4-7 elsewhere. Skill is poor to good at 50 to 75 % consistent.
