Summary
Rainfall outlook for the South West Land Division for the next 3 months November 2023 to January 2023, is for below median rainfall, based on a survey of 20 national and international models. Warmer temperatures than normal are also expected.
Things to consider:
- The Bureau of Meteorology’s ACCESS model indicates that there is a 50 to 80% chance of unusually high minimum and maximum temperatures for November 2023 to January 2024. Meaning that the next 3 months will be amongst the hottest 20% of seasons for this time of the year.
- Rainfall outlooks for December 2023 to March 2024 indicate below median rainfall is likely.
- An El Niño is present in the Pacific Ocean and is expected to last until at least March 2024. El Niño’s have some influence on summer temperatures in the South West Land Division (SWLD), with usually warmer temperatures than normal.
- A positive Indian Ocean Dipole (IOD) has developed in the Indian Ocean. This event is unusual, as models expect it to remain in place until January 2024. IOD events usually end in October, when the Australian monsoon season begins. Past positive IOD means below average rainfall and warmer maximum and minimum spring temperatures for the SWLD.
- When a positive IOD and El Niño occur together, their drying effect is typically stronger and more widespread across Australia.
Rainfall outlook for the South West Land Division
Summary of 20 national and international models show that 12 out of 20 models indicate below normal chances of exceeding median rainfall for the SWLD for the next 3 months. Further ahead, 3 of 7 models indicate a wetter than normal outlook, while another 3 indicate a drier than normal outlook for February to April 2024. Remember, however, the further out the model forecasts, the least skill it has.
3 month temperature outlook from the Bureau of Meteorology
The Bureau of Meteorology ACCESS model is indicating an 80% chance of unusually high maximum temperatures for November 2023 to January 2024. This means that the November 2023 to January 2024 period will be amongst the hottest 20% of seasons for this time of the year. For minimum temperatures, the chances are lower at 40 to 70%, with higher chances for the interior.
Recent climate
Rainfall decile map 1 April to 31 October indicates decile 1 to 3 rainfall for the majority of the South West Land Division. Parts of the Central Wheatbelt, South West, Great Southern, South Coastal and South East Coastal forecast districts, received decile 8 to10 rainfall.
Frost occurrences for August to October 2023 were below average when compared to the average number of nights below 2°C for the years 2000 to 2022.
For information on climate drivers refer to the Bureau of Meteorology’s Climate Driver Update.