Quote:
Originally Posted by Startrek
Thanks Gary for the latest forecasting from BOM and ABC
My comment about La Niña occurring now was merely speculative , however the info from BOM I found had it turning from neutral to positive by June / July
Thank goodness it’s only a “Blocking High” for a week or so
Hopefully clearer skies late May
Martin
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Thanks Martin,
The big joker in the pack now is record high sea surface temperatures.
El Nino, of course, is defined in terms of observed phenomena such as
a sea surface gradient and reverse in the direction of trade winds in the
Pacific at tropical latitudes.
In the past during El Nino years what was often observed was that the
water temperatures off the east coast of Australia would tend to become
cooler.
There would be one of those hot, dry days we would associate with El Nino
here in Sydney but you would get a surprise if you went for a swim at the
beach as to how nippy the water was.
But not this year.
This year there were abnormally high sea surface temperatures down the
east coast.
So much so that at one point it was calculated there was enough energy
in the oceans down near Bass Straight that in theory it could create
a cyclone.
With water temperatures so high this summer it resulted in hot, humid,
topical conditions here in Sydney.
On the 25th January this year, I took a couple of screen shots of
how warm the waters were off the east coast (images attached).
These warmer than average sea temperatures off the east coast were consistent
with record high global sea temperatures during 2023-2024.
As mentioned by the BOM, abnormally high global sea temperatures mean
how the ESNO responds may not follow patterns of the past.
ABC has another article today about the sustained 'blocking high' :-
https://www.abc.net.au/news/2024-05-...-nsw/103810112
Meanwhile Brazil has recently experienced a blocking weather system of its
own which blocked cold fronts and concentrated areas of instability over the southern-most
state of Rio Grande do Sul. This resulted in record rain fall in recent days breaking 150 year-old records.
There has been significant flooding. The regions affected correspond to about the latitude of Grafton in NSW.