This synoptic set up is akin to a mid-strength black nor’easter, with an impressive fetch stretching all the way from Far Southern NSW to Fiji and Tonga.
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A very unstable, dynamic synoptic chart this week with a large high (1034hPa) moving from the Bight through Victoria, with a coastal trough deepening off the Mid North Coast on the leading edge of the high directing very moist onshore winds across Central NSW, extending up into the sub-tropics.
We’ve got good model agreement now that through Mon we’ll see a deep trough develop from the Coral Sea down to a terminus somewhere on the MNC to lower North Coast with good odds we will see a surface low develop at that terminus.
Next week still looks dynamic with potential for a deep trough or low in the Tasman, although we are going to have to play it day by day due to poor model to model and run to run consistency.
The recent pattern of very strong highs moving through the Bight into the Tasman then resets over the weekend with a high likelihood of another surge of S-SE swell during this period
There’s actually a couple of E/NE swell sources for early next week. And a S'ly swell too!
In between, a trough and cold front are currently approaching Tasmania, expected to bring a vigorous S’ly change o/night, bringing a spike in short range S swell short term.
We’ll see the current dominant high (1034hPa) over New Zealand which is directing a broad trade fetch through the South Pacific and into the Coral Sea slowly migrate eastwards this week with an E’ly dip form a trough of low pressure due E of SEQLD mid week.
A dominant (1034hPa) high pressure system is currently moving off the Far South Coast into the Tasman Sea where it very slowly migrates south-eastwards over the weekend. Pressure gradients weaken over temperate NSW with a firm ridge in the sub-tropics holding a S-SE pattern over the weekend.
We’re seeing a ramp up in strong S’ly winds along the eastern seaboard as a dominant high (1035hPa) moves through the eastern Bight towards Tasmania with a trough on it’s leading edge moving northwards. Remnants of a low on the weekend are also sitting near New Zealand with swell generating fetches off the South Island and emerging from Cook Strait into the eastern Tasman.