The latest long-range outlook update from Australia’s weather agency through July this year was unchanged last week, although the prospects worsened slightly in Western Victoria and Sth East South Australia. BOM says the outlook is influenced by several factors including an ENSO-neutral pattern (neither El Niño nor La Niña) that is tending towards El Niño by mid-winter, while there is a chance that a positive (Indian Ocean Dipole) IOD event may develop in coming months.
For May to July, BOM said below average rainfall is “likely to very likely” (60% to greater than 80% chance) for almost all of Australia, while maximum temperatures are likely to very likely (60% to greater than 80% chance) have the same likelihood of being warmer than average for almost all of Australia.
BOM said earlier in the month that all climate models suggest the IOD would trend positive in the coming months, which can supress winter and spring rainfall over much of central and southeast Australia, and if combined with El Niño, the drying effect is typically stronger and more widespread across Australia. However, BOM said model accuracy is generally very low at this time of year, therefore outlooks through and beyond autumn should be viewed with caution.