THE La Nina event that has developed in the past month or so has strengthened little in recent weeks as indicated by an increasingly prominent pattern of below-average sea surface temperatures (SSTs) across the central and eastern equatorial Pacific Ocean and warmer waters especially in the Tasman Sea.
The atmospheric circulation over the tropical Pacific Ocean also reflected La Nina, with convection suppressed near the International Date Line and enhanced over Indonesia.
Also, the south-east trade winds were stronger than average over the western tropical Pacific so both the ocean and atmosphere system reflect at least a weak La Nina.
Such events more often than not bring above average rainfall to large areas of eastern Australia.
However, late season and weak La Nina events like this current one, often do not reflect the typical conditions for a La Nina.
Consequently, only slightly enhanced probabilities for above normal rainfall are expected in scattered parts of eastern Australia over summer and early autumn.
Variability will continue to be a feature.
After the significant rain events a few weeks ago, a more stable weather pattern has developed and it looks as though it will persist for the rest of the year.
The developing monsoon in the north of the country has retreated well away from Australia in the past few weeks.
It has headed back towards the Equator and remained to the north.
As a result, less cloud in the north-west “heat engine” area of the continent has meant increasing temperatures which, in turn leads to increase in the potential for “heat wave” conditions to spread into the south-east states, given a suitable synoptic set up.
The monsoon is favoured to return to the north before the end of the year so more moisture might again become available early in January.
Nevertheless, I hope the weather will be kind to you in 2018 and may you “weather” the year in peace and fulfillment.