Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Wednesday 9th September)

Best Days: Thurs: strong combo of S'ly and S/SE swells, with a brief period of early offshores. Fri: morning offshore winds and easing southerly swells. Sat/Sun/Mon: small southerly swells and morning offshores. Tues/Wed: building S'ly swell. Thurs onwards: large S'ly swell.

Recap: Tuesday saw plenty of fun, albeit initially inconsistent waves from the S/SE in the 2-3ft range in the morning, before many beaches pulsed to 3-4ft+ through the afternoon (as per the screen grabs attached, from Bondi). Conditions were clean all day with offshore winds. Today a stronger combination of the same S/SE groundswell and a secondary S’ly swell have provided larger 5-6ft surf at south facing beaches. Early offshore winds swung fresh southerly mid-late morning. 

This week (Sep 10 - 11)

We’re looking at another strong day of swell for Thursday, from the same sources as today. Our existing S/SE groundswell is expected to hold into Thursday morning before easing into the afternoon. This swell is probably worth somewhere in the realm of 4ft at most open south facing beaches, but the overlapping southerly swell will contribute larger waves near 4-6ft (the Hunter should see easy 6ft+ bombs). 

Surface conditions are looking a little ordinary at exposed beaches though, as a high in the Bight will maintain fresh southerly winds about the coastal margin. There’s a reasonable chance for a period of lighter W/SW winds for a few hours at dawn, so you’ll have to make the most of this time frame. Otherwise, sheltered southern ends will have small clean waves all day.

Friday will then see both swells pull back steadily during the day. Most south facing beaches should see early 3-4ft sets (bigger in the Hunter) but it’ll be smaller at those locations not completely exposed to the south, and wave heights will taper off into the afternoon. Fortunately, conditions should be really good in the morning with early light W/NW winds ahead of a freshening NE sea breeze after lunch. So once again, the early session will score the biggest and cleanest waves of the day. 

This weekend (Sep 12 - 13)

No changes to the weekend forecast at this stage.

In tandem with easing swell from the end of the week, we’ll see a new S’ly swell push through on Saturday and hold into Sunday, originating from a series of strong but poorly-aligned fronts in the Southern Ocean (well below the Tasman Sea) today and tomorrow.

Our swell model isn’t picking up these events very well (periods are fine, but Hsig is significantly under) so despite the lacklustre model guidance I think we’ll see good surf both days in the 2ft+ range across Sydney’s south facing beaches, with bigger bombs in the Hunter. However, set waves will be extremely inconsistent and beaches not directly open to the south will see smaller waves. 

There’s also a chance for a minor NE windswell at exposed beaches early Saturday morning, originating from overnight N/NE winds on Friday night - however I don’t think we’ll se much size from this, and it’ll be mainly confined to the South Coast. 

Also, some models have a brief N/NE fetch off the lower Mid North Coast and Hunter region on Saturday night, which I’ll keep an eye on for NE swell potential for Sunday but at this stage it doesn’t look very promising.

As for local winds, we’re looking at a general northerly flow, which means early nor’westers tending nor’east into the afternoons. I can’t really pick a better morning to surf between Saturday and Sunday, they both look very similar at this stage but I’ll update this on Friday with the availability of more data. 

Next week (Sep 14 onwards)

A stronger front/low combo traversing the waters south of Tasmania late Friday and into Saturday is expected to generate another small long period S’ly groundswell for Monday morning.

Owing to stronger winds, there’s the potential for bigger sets than what we’re expecting over the weekend - but it’s a line call at this stage, especially as the swell model is estimating even less size than the weekend (0.2m @ 16 seconds). For now let’s hold it steady at an inconsistent 2ft+ at south facing beaches, with bigger bombs in the Hunter - but I think the overall storm track will hinder this event and a downgrade in Friday’s notes is quite possible.

The latter stages of this system as it pushes beneath New Zealand (late Sat/Sun) holds a little more promise, but the fetch will be considerably off axis so again we’re only likely to see small sideband energy. If nothing else this should maintain small levels of south swell through the middle of the week. I’ll review the details again on Friday.

Elsewhere, a locally freshening N’ly flow from late Sunday through Monday should whip up a small NE windswell, up until the point of a S’ly change (currently due overnight Monday). At this early stage NE swell magnets may rake in a few 2ft+ sets throughout Monday but this will become clearer by the end of the week.

Monday’s late change will be associated with a series of fronts forecast to impact the state over the coming days. Early model indications are that the first few systems won’t have much strength but should kick up some small southerly energy through Tuesday and Wednesday (say, 2-3ft sets at south facing beaches Tuesday, 3-4ft+ Wednesday, smaller elsewhere). 

However a much more powerful low is scheduled to trail behind and is currently on target for a very large S’ly groundswell to arrive during the second half of next week. I’ll have more on that in the coming days.