Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Wednesday 18th November)

Best Days: Fri: building NE windswell with a chance for OK winds early AM. Sat AM: brief window of peaky NE windswell and S'ly winds. Early/mid next week: building S'ly tending SE swells from a new Tasman Low. 

Recap: Tuesday saw building S’ly swells to 2-3ft on Tuesday afternoon (smaller elsewhere, bigger in the Hunter) but conditions were average with mainly moderate onshore winds for much of the day, early S/SE then tending E/SE just before lunch. This south swell was a brief event and eased back to 1-2ft this morning, and we’ve seen average conditions with light E/NE winds freshen a little through the day.

This week (Nov 17 - 20)

No real change to the forecast for the next few days.

A broad, slow moving high in the eastern Tasman Sea and an approaching trough of low pressure to the west will tighten a NE flow adjacent the coast into Thursday, which will slowly build a local windswell. Initially, wave heights will be very small in the morning and it’ll trend up through the day, however we probably won’t see a respectable surfable size until Friday, when NE facing beaches should increase into the 2-3ft range, a little bigger south from the Illawarra thanks to the longer fetch length.

Unfortunately, it’s likely that we’ll see northerly winds persisting all day Friday. An approaching southerly change associated with the backside of the trough isn’t expected to reach the Illawarra until just after dinnertime (if anything, it’s been slightly delayed in the latest model runs) so conditions are looking a little average - though there’s a chance for a brief window of light winds early Friday morning. 

So, there’ll be options to finish the working week but expect patchy conditions. 

Oh, and just to reiterate a byline from Monday's notes, we may see some small long period S'ly lines at the swell magnets on Friday but I don't think there'll be much in it. 

This weekend (Nov 21 - 22)

Fresh southerly winds trailing Friday’s meandering trough will envelop the coast overnight into Saturday, creating bumpy conditions at exposed beaches through the morning. 

The good news is that the NE fetch responsible for Friday’s NE swell should remain active in our swell window until just before midnight, which means the early session Saturday should still retain some size - I’m probably being a little overly optimistic, but exposed NE swell magnets should pick up a few stray 2-3ft sets before it eases to 1-2ft by lunchtime, becoming smaller into the afternoon. 

There’ll also be some building S’ly windswell in the mix (to a bumpy 1-2ft) but quality will be low at these beaches facing due south. The parent low to the change - E/SE of Tasmania on Friday - looks impressive in single synoptic snapshots (see below), but it moves too quickly to the east (perpendicular to the swell window) to properly generate any meaningful energy for Southern NSW. 

The onshore flow should throttle back through Saturday, becoming light to moderate S/SE by mid-late afternoon, and Sunday will be much cleaner with light variable winds and sea breezes. Unfortunately, all of our swell sources will be gone by then so we’ll have to scrounge around for minor leftovers at the swell magnets. 

So, make the most of Saturday!

Next week (Nov 23 onwards)

Sunday’s light variable winds will be associated with a broad region of coastal troughiness, which is - as discussd in Monday's notes - expected to evolve into an impressive Tasman Low (see below) thanks to the influence of a front passing to the south. 

The dynamics on this are not presently clear, as it's still an evolving solution, but at this stage we’re looking at a solid swell event from Tuesday through Wednesday, initially from the south tending south-east, and exposed beaches could push 4-6ft at the height of the event. 

Let’s give the models a few more days to sort themselves out, and have a closer look on Friday.

See you then!