Summary
The Department of Primary Industries and Regional Development’s (DPIRD) Statistical Seasonal Forecast (SSF) outlook for spring, September to November, 2022 is indicating mostly neutral (40-60%) probability of above median rainfall for the majority of the South West Land Division.
- For spring, September to November, the SSF forecast is indicating mostly neutral (40-60%) probability of above median rainfall for the majority of the South West Land Division. Greater than 60% probability for part of the Central West, Lower West and western part of Great Southern forecast districts. With less than 40% probability for parts of the Central Wheatbelt and Great Southern forecast districts. The most likely decile range map is indicating decile 8-9 for parts of the Central West, Central Wheatbelt, Lower West and Great Southern forecast districts. Decile 2-3 for parts of the Central Wheatbelt, Great Southern forecast districts, and Ravensthorpe shire, and decile 4-7 elsewhere. Skill is poor to good at 50 to 75 % consistent.
- The Bureau of Meteorology’s seasonal outlook for spring, September to November 2022 is indicating 25-55% chance of exceeding median rainfall for the SWLD. Predictive skill is poor to good (45-75% consistent). The current longer-term outlook (at time of writing) for October to December 2022 is 30-50% chance of exceeding median rainfall with mostly poor skill (45-65%).
- Temperature outlooks for spring, September to November 2022, from the Bureau indicate a 30-80% chance of above average day-time maxima, with the lower chances inland. Skill is 75-100%. For night-time minima for the SWLD, the Bureau is indicating 50- 80% chance of exceeding above average temperatures, with the higher chances along the coast. Skill is moderate to high at 55-100%.
- August rainfall was above average for the majority of the SWLD. The main rain event 16-18 August was due to a rainband linking up with a cold front. August maximum temperatures were average, with minimum temperatures mostly close to average. Widespread frost has recorded for the last three days of August.
- The main climate driver influencing South West Land Division climate is the positive Southern Annular mode, which will have a drying influence for parts of south-west. SAM values are expected to be generally positive throughout spring and into early summer. The Indian Ocean Dipole (IOD) is currently negative and likely to remain through to November. Past negative IOD events generally increase rainfall in the eastern grainbelt.
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 spring, September to November, the SSF forecast is indicating mostly neutral (40-60%) probability of above median rainfall for the majority of the South West Land Division. Greater than 60% probability for part of the Central West, Lower West and western part of Great Southern forecast districts. With less than 40% probability for parts of the Central Wheatbelt and Great Southern forecast districts. The most likely decile range map is indicating decile 8-9 for parts of the Central West, Central Wheatbelt, Lower West and Great Southern forecast districts. Decile 2-3 for parts of the Central Wheatbelt, Great Southern forecast districts, and Ravensthorpe shire, and decile 4-7 elsewhere. Skill is poor to good at 50 to 75 % consistent.
