There’s currently a robust Tasman low, still intensifying, moving slowly SE off the Central NSW coast down into the Tasman Sea towards New Zealand. Gales to severe gales wrapping the SW flank of the low will supply plenty of strong, improving S’ly-SE'ly swell through the rest of the week.

The moist onshore flow from this set-up is flowing into a coastal trough and interior low bringing onshore winds and rain. We’ll eventually see the low clear the coast bringing better winds Sun with some strong S swell pulses on the menu from Sun and into next week from Tasman Sea and deeper sources.

A complex inland trough low tied to tropical sources exits the coast as a strong high moves into the Bight. Following that a coastal trough in the Northern Tasman then deepens, likely into a surface low which may drift southwards bringing strong E swells to the entire region, possibly followed by a return S swell as the low gets captured by an approaching front.

Weak coastal troughiness will contract to the North Coast on Thursday though lingering onshore SE winds are a risk north from Sydney.