CLIMATE UPDATE - NEXT 4 WEEKS UPDATED - FRIDAY 11TH JUNE 2021

Headlines


  • No real change in the colder and wetter signal for southern and western Australia with the SAM and Indian Ocean Dipole set to take control of Australia's weather.

  • Indian Ocean the stronger influence later in the period and as we go into spring.

Summary



Temperature Outlook - % chance of exceeding the median temperature for the coming 4 weeks. Valid Friday 11th of June 2021.

Rainfall Outlook - % chance of exceeding the median rainfall for the coming 4 weeks. Valid Friday 11th of June 2021.

We have seen excessive cold weather for the past few weeks over large parts of southern and eastern Australia with near record values over parts of NSW and southern QLD mid this week. Below average temperatures continue for the next few days as we see the upper air heights slowly recover.


CFS 500mb/18000ft upper air pattern - Next 4 weeks - Valid June 11th 2021.

This model is not the greatest when it comes to skill score against other medium term global modelling, but to contrast away from GFS and Euro for a moment, even these models which can turn a little more whacky, are showing similar signals, so the broad trend for colder and more active weather over the coming few weeks remains high. And of course there will breaks in the cold and blustery weather, but it is looking like a wavy and active pattern for the most part.

The ensembles are looking colder for a lot of Australia over the coming weeks, with bursts of colder air working their way north. The trend for warmer weather over northern Australia remains above 50% on the data sets, but in the past few days of observed temperature, many areas in yellow and orange tones have had below average day time temperatures. And with the increased risk of cloud bands developing later June into July, there could be spells of below average temperatures for northern Australia.


Euro Temperature Anomalies Outlook - Valid June 11th 2021.

GFS Temperature Anomalies - Valid June 11th 2021

A much warmer bias which I am not buying at this time.

Indian Ocean Dipole expected to continue to take the plunge as we head into winter with the likelihood of further thick cloud developing and cooler temperatures across large parts of southern and eastern Australia if this current trend continues.

The outlooks from the global model suite are largely unchanged at this time.

IOD - September Outlook 2021

IOD - October Outlook 2021.

The above will have a large influence on rainfall in the longer term, in the shorter term we are starting to see hints of that developing on the rainfall outlooks which is encouraging, but these are signals, not forecasts, so watch the trends closely over the coming weeks to see how that stacks up in reality. And keep an eye out on the short term forecast products.


Rainfall Signals for the coming 7 weeks showing the wet weather building over southern and western Australia in line with the climate shift. Note the surge of possible rainfall coming into northwest Australia during the latter part of the period with northwest cloud band potential being offered by some global modelling.


Euro Rainfall for the next 7 weeks - Valid June 11th 2021.

And little change in the remainder of winter rainfall anomalies - with July through September posing some good rainfall over parts of inland Australia and very heavy rainfall over Indonesia a sign of that IOD tending negative and propelling moisture south and east through the jet stream.


Seasonal Rainfall Outlook - July through September 2021. Euro Model.

Finally the global SSTS are looking encouraging for rainfall to remain above average through the continent, on current forecast trends, supporting international modelling with a wetter phase developing as we go through winter into spring.


SSTs anomalies forecast for July to September 2021.

La Nina is increasing in chance with a larger update expected on that next week, for now I will keep the trend neutral for the ENSO.


Euro ENSO forecast for the coming 6 months - Valid June 11th 2021.

Note the values for the period are generally evenly split but there is a slight bias towards a negative trends in the spring and summer but not overwhelming to be declaring anything other than a neutral outlook, however this can change rapidly during this period. One way or the other, El Nino is not set to develop.

More updates on climate due again next week, more data coming out for July to watch from IRC and I will have updates on my rainfall and temperature outlooks then with another write up, taking a bigger look at July as a whole.


Need more information surrounding climate for your part of the world? Email me at karllijnders@weathermatters.org




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