CLIMATE - ANOTHER LOOK AT WINTER 2022.

A few shifts in the guidance from the Climate drivers in the recent weeks with some indication that the La Nina drags on through later Autumn and may even lag into Winter and that through the back half of Winter the Indian Ocean Dipole may turn negative as head into Spring.


If those two elements are in play and do verify, then this does drag on the wetter weather for parts of the east and north through early Winter and the rainfall for southern and southeast areas of the nation under the Indian Ocean Dipole would be somewhat turning wetter through the back half of Winter through to Spring.


While pinning down the Climate drivers is somewhat of low confidence at this time of year, it should be noted there has been a shift towards a wetter trend for the southern two thirds of the nation, basically areas away from the tropical north where we will see the dry season underway.


Lets take a look at the latest forecast guidance

FORECAST

%chance of exceeding or not exceeding the median rainfall for Winter 2022

Moisture may linger for parts of northern Australia from the prolonged wet season and that could linger further offshore over Indonesia and PNG through much of Winter feeding troughs over northern Australia bringing showery weather and assisting in cloud bands bringing light dry season falls to interior parts. Over the southwest of the nation, the early productive start to the wet season that is expected through May is forecast to continue through June and July with locally heavy rainfall thanks to a reasonable supply of cold fronts and moisture being drawn southeast from the Indian Ocean seeing a potential above average season of cloud bands. The offshoot moisture from the above average wet season through the SWLD of WA may also promote higher rainfall frequency and intensity for parts of Ag SA and through the food bowl in the east. The lighter green shading for much of the nation indicates the possibility of larger cloud bands developing through the Winter season. Over the east coast, a wetter June thanks to the lingering La Nina will ease by July and August as the region moves into dry season. This region as per last year, could go many weeks without too much measurable rainfall.

%chance of exceeding or not exceeding the median temperatures for Winter 2022

Temperatures are fairly similar to last year's outlook with many areas of northern and eastern Australia returning to seasonal values through June but turning above average through July and August with the heat values and humidity values increasing ahead of schedule. This is in part thanks to the lack of cold fronts surging northwards and containing the colder air to southern Australia and/or the elevated SSTs over northern Australia leading to these above average day and nighttime temperatures. The persistent rainfall over the SWLD of the nation may lead to some areas down in the region recording slightly below average temperatures through the period and this could also impact far southwest VIC, southeast SA and TAS. But it is a conditional risk. Most of the nation is looking at seasonal temperatures.

RAINFALL DATA SETS - JUNE THROUGH AUGUST

You can review all the data sets via my video update.

IRI Rainfall Outlook - % chance of exceeding or not exceeding rainfall for April through June 2022

More on this coming up in the next few days - but certainly some signals that the wetter weather may increase across the nation during the Winter.

TEMPERATURE ANOMALIES - JUNE THROUGH AUGUST

IRI Rainfall Outlook - % chance of exceeding or not exceeding temperatures for June through August 2022

The above average temperatures may persist over northern Australia? Could that indicate a failed dry season with more humidity? Or is that indicating a persistent hot dry airmass? The south of the nation looking relatively seasonal for now. But more on this coming up in the coming days.

KEY POINTS

Refer to video for further information

This is a preview for a more specific forecast coming up in May as the better data sets come in and we can see how the back half of Autumn is performing so stay tuned for that!

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