LITTLE change has occurred in the major climate indicators in the past week, with the Southern Oscillation Index (SOI) staying strongly negative and Southern Annular Mode (SAM) staying positive.
These two indicators remain the only ones that are currently against the prognosis of at least average rainfall for the rest of 2016.
However, sea surface temperatures (SSTs) in the eastern Pacific continue to fall and although we are still in an “El Nino” event, it is not likely to last much longer.
In fact, the majority of international climate models indicate there will be a return to neutral conditions within the next month.
Therefore, there is a slight increase in the chance that the SST patterns in the Pacific will swing around to a “La Nina” by spring.
Whereas an “El Nino” does not always mean drought, then a “La Nina” does not always mean wet conditions but the probability of at least average rainfall in much of South East Australia in the coming months is increasing.
Also supporting this scenario is the above average SSTs in the Indian Ocean, which are persisting.
The extended period of stable conditions in the past couple of months has looked like ending a couple of times recent but it is favoured to end in the coming weeks.
Rain events might be patchy at first because significant Southern Ocean fronts are some weeks away.
The warmer SSTs around the Australian continue to assist in creating above average temps for much of winter.
However, variability is likely to be a feature and the occasional brief but significant cold spells are more likely in the coming winter than they have has been in recent years.
Nevertheless, in a warmer world, temperatures overall will stay up on normal with the preliminary outlook for next spring and summer showing at least a 75 per cent chance of above average temps although without an “El Nino”, temperatures will be a little down on last year.
