THE two most significant features of the world’s weather in recent years have been the global warming which has occurred at a level unprecedented in recorded history and variability in weather in parts of the world which has led to more extreme events than would normally be expected.
March 2016 followed February 2016 as record warm months by record margins since data was collected in 1880 and early indications are that April will be similar.
The “El Nino” has probably contributed to this a little so temps may fall slightly over the coming year but still staying above normal.
Warmer sea surface temps around continental Australia could be helpful in the production of the occasional rain event.
With global variability likely to effect Australia, this could mean extended periods of stable, dry weather interspersed by the occasional significant rain event, bringing sufficient moisture to push totals above average.
This is the current preferred scenario for the coming months.
The same is also likely to apply to temperatures – extended periods of stable weather will mean extended spells with slightly to moderately above average temperatures interspersed by the occasional, brief but significant cold outbreak.
These will depend on Southern Ocean fronts becoming more significant, which is expected during winter.
Into the latter months of 2016 (say spring and early next summer), long-term modelling indicates there’s about a 40 per cent chance of neutral conditions and a 60pc chance of “La Nina” conditions developing.
This is also based on previous years when an “El Nino” collapsed in autumn.
Statistically, more than half the neutral years
and three quarters of the “La Nina” years had above average spring rainfall in NSW – so half of 40pc is 20pc and three quarters of 60pc is 45pc – meaning there’s around a 65pc chance of above average rainfall in spring – both statistically and meteorologically speaking.