Rain only a ‘patchy’ novelty

In fact, the above average temperature predictions for late spring and summer have a higher level of confidence than any rainfall predictions. 

Severe moisture deficiencies are already established in many parts of northern and central NSW. 

In the other areas, such as in the north-eastern inland and in the south, current moisture deficiencies are not as serious, but reserves of moisture are low so those areas will be susceptible to rising temperatures and increased evaporation in spring anyway. 

As indicated previously, any “relief” from the current dry weather in the coming months will come in the form of brief but significant one off events effecting only parts of the state. 

Such events can bring close to monthly average rainfalls in a matter of days but they will be few and far between and some areas will miss out on them completely. 

The dependence on such event is far from ideal because they are unpredictable and patchy. 

So it means that – overall – the chances of rainfall remaining below average for the coming months remains fairly strong. The main reason why the confidence level for rainfall predictions is lower is that there are still a few conflicting signs. 

The main “positive” is that sea surface temperatures (SSTs) around much of continental Australia, as well as over the Tasman Sea and in the eastern Indian Ocean remain above average. 

Even in the typical El Nino development areas of the tropical eastern Pacific, SST anomalies are minimal. 

So there are likely to be occasions in the coming months with reasonable moisture availability. 

Whether this will manifest itself into one of those “one off” rain events or just increase the chance of severe storms in late spring and early summer remains to be seen.