A WEATHER pattern more typical of a dry spring appears to be developing in the Australian region after a few weeks in late August and early September of cool weather.
Temperatures in Australia’s “heat engine” – the north-west inland of the continent, have already touched 40 degrees Celsius on a couple of days recently and it is only a matter of time before air from this region will start to drift to the south east.
An unusual feature of the weather patterns in recent months has been the lack of moisture or upper cloud drifting across the continent from the north west and adjacent Indian Ocean, despite sea surface temperatures in the tropical north-eastern Indian Ocean holding to slightly up on normal.
The above average SSTs in the Tasman Sea continue to present a confusing signal for the south-eastern states.
They provide one slightly optimistic feature and their existence is one reason to believe that the effects of the developing Pacific Basin El Niño event later this year might not be as significant as first thought.
The Southern Oscillation Index continues to be negative with the 30-day running mean almost in El Nino territory on about -6, and confirms its development.
There is now about a 60pc chance of El Niño developing during spring, rising to 70pc for summer 2018-19.
Latest models continue to favour weak El Niño development by October growing to weak or possibly moderate strength during December.
The warmer SSTs provide occasional opportunities for moisture to feed into astern Australia (mainly coast and ranges and north-eastern inland in NSW) although this will be restricted overall by the developing El Nino.
Nevertheless, the potential is there for an occasional significant rain event to briefly relieve dry conditions in some areas but unfortunately, it is difficult to determine which areas and general rain events are not favoured at this stage.
So the chances are - for many parts of the state - drier than normal weather with above average day temperatures will be a feature of the weather for the rest of the year.
