THE CLIMATE KELPIE BLOG: What’s predicted in May?

Posted by BCG on 6th May 2020

The main climate drivers are continuing to not play a big role in influencing our climate at the moment, however ‘Above Average’ temperatures in the eastern Indian Ocean are currently having some impact. These warmer temperatures are helping to bring tropical moisture across central and southern Australia, a pattern which looks likely to continue over winter with several models indicating the potential development of a negative Indian Ocean Dipole (IOD).

As a result, the overall outlook for May to July is for ‘Above Average’ rainfall for most of the southern two-thirds of Australia however, the Eastern Seaboard has no strong indication of wetter or drier than average conditions. Both minimum and maximum temperatures are likely to be ‘Above Average’ for most of Australia.

Rainfall Roundup

Above Average” and “Very Much Above Average” rainfall was recorded in much of south eastern Australia; however Western Australia is still waiting for the autumn break (Fig. 1). Nonetheless with these recent autumn rainfall events in south east Australia there are still large areas that have serious rainfall deficiencies which will require many months of ‘Above Average’ rainfall (Fig. 2).

Figure 1. Rainfall deciles for April 2020.
Figure 2. Rainfall deciles for February to April 2020.

Rainfall Forecast

The BoM’s ACCESS model suggests that May is likely to deliver ‘Average’ to ‘Above Average’ rainfall to much of Australia (Fig. 3). For the three-month forecast, May to July, rainfall is likely to be ‘Above Average’ for much of the southern two thirds of Australia however, parts of the tropical north and eastern side of the Great Dividing Range have roughly equal chances of being wetter or drier than average. Note that at this time of year accuracy for the three-month forecast is moderate except for areas in the south east of Australia, particularly South Australia, and areas in New South Wales and Queensland where accuracy is low (Fig. 3).

Figure 3. Australian outlook for May to July 2020.

Temperature Roundup

Maximum temperatures in April were ‘Below Average’ in parts of south eastern Australia but were ‘Above Average’ across northern and western Australia (Fig. 4). These ‘Above Average’ temperatures broke many records in Western Australia. For example, Perth recording its hottest April day on record (39.5°C) and Mandora (SW of Broome) now holds the record for latest 42°C day ever recorded (26th April).

Minimum temperatures on the other hand have been ‘Average to ‘Above Average’ across most of Australia however a large part of Western Australia was ‘Very Much Above Average’ with small areas being the ‘Highest on Record’ (Fig. 5).  

Figure 4. Maximum temperature deciles for April 2020.
Figure 5. Minimum temperature deciles for April 2020.

Temperature Forecast

The BoM’s ACCESS model forecast suggests that over the next three months maximum temperatures are likely to be ‘Above Average’ across northern, eastern and the far southwest of Australia (Fig. 6). Minimum temperatures are also likely to be ‘Above Average’ right across Australia for the next three months (Fig. 7). At this time of year accuracy for the three-month maximum temperature forecast is moderate to high for most of Australia except for parts of the NSW coast and an area in the Northern Territory and Queensland where accuracy is low. Accuracy for minimum temperatures is moderate to high in northern Australia and Tasmania at this time of year however the south western part of Western Australia and the south eastern states have low accuracy.

Figure 6. May to July 2020 maximum temperature outlook.
Figure 7. May to July 2020 minimum temperature outlook.

Climate and Water Outlook Videos

The Bureau of Meteorology releases regular outlook videos, covering all this information. Watch the most recent video below.

Leave a Reply