THE CLIMATE KELPIE BLOG: What’s Predicted in July

Posted by BCG on 2nd July 2019

The BoM ENSO outlook has dropped back from ‘El Niño Watch’ to ‘El Niño Inactive’. This is due to ocean temperatures in the tropical Pacific easing from El Niño thresholds with most models forecasting a continuing decline over the coming months. The positive Indian Ocean Dipole however, looks likely to persist. The state of these climate drivers mean higher pressures are more likely over southern and eastern Australia, potentially reducing cloud formation and keeping cold fronts further south than usual. Drier and warmer than average conditions are predicted to continue across southern Australia through July to September.

Rainfall Roundup

Very dry conditions have persisted across large parts of Southern Australia during June, prolonging the drought in several areas particularly in the northern Murray Darling Basin (Fig 1). Whilst Western Australia (WA) has had an extremely dry start to the year, some areas have received timely rain in June (Fig 1). For example, the central west district of WA has had more rain in the first 12 days of June than in the previous nine months. Good rain falls have also occurred in parts of Victoria, with areas in Western Victoria receiving ‘Above Average’ to ‘Very Much Above Average’ rainfall. These rainfall events have helped increase the overall three-month decile for those regions however, many areas are still ‘Below Average’ to ‘Very Much Below Average’ across Australia (Fig. 2).

Figure 1. Rainfall deciles for June 2019.

Figure 2. Rainfall deciles for April to June 2019.

Rainfall Forecast

The BoM’s ACCESS model suggests ‘Below Average’ rainfall is more likely for large parts of Australia with parts of SE Australia and SW Western Australia having a 25-40% chance of exceeding the median rainfall over July to September (Fig 3). The skill of this model improves greatly heading into August and September providing improved certainty coming into Spring.

Figure 3. Australian outlook for July to September 2019.

Temperature Roundup

In June maximum temperatures have been “Average” for large parts of Australia (Fig 4). Most of WA, Tas, Vic and parts of NSW however, have remained ‘Above Average’ (Fig 4).

Minimum temperatures were ‘Below Average‘ to ‘Average’ across most of Australia apart from a few pockets in northern Australia, WA and the coastline for NSW and QLD where ‘Above Average’ minimum temperatures were recorded (Fig 5).

 

Figure 4. Maximum temperature deciles for June 2019.

Figure 5. Minimum temperature deciles for June 2019.

 

Temperature Forecast

The BoM’s ACCESS model forecast suggests ‘Above Average’ maximum temperatures are more likely across most of the country from July to September (Fig 6). Parts of southern WA and far north Queensland however, have equal chances of being warmer or cooler over this period (Fig 6).

Minimum temperatures are likely to be “Above Average” across much of northern Australia, Tasmania and the east coast (Fig 7). There is roughly an equal chance of warmer or cooler nights across much of the southern mainland however, with more cloud-free days and nights expected there is an increased risk of frost in susceptible areas.

 Figure 6. July to September maximum temperature outlook.

 Figure 7. July to September 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.