Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Wednesday 21st September)

Best Days: Thurs: A small E/SE swell may produce peaky beachies (more likely the afternoon) with good winds north of the 'Gong. Fri: best options inside southern corners. Sat/Sun: easing swells with good winds. Mon: new S'ly swell with likely good winds. 

Recap: Monday’s south swell reached a higher peak overnight than expected, which meant although Tuesday’s easing trend panned out inline with expectations, we began the day a foot higher across south facing beaches (3-4ft against the forecast of 2-3ft). Smaller waves were reported into the afternoon and today has leveled out at a similar size - a little bigger than forecast, though set waves are very inconsistent. Both yesterday and today began with early light offshore winds ahead of an afternoon sea breeze. 

This week (Thursday 22nd - Friday 23rd)

Thursday is expected to start off rather small across all beaches as the current swell sources dry up. We have a small new round of SE thru’ E/SE swell due throughout the day, originating from the slightly-reinvigorated Tasman low that provided our Mon/Tues swell: it’s now occupying the New Zealand region and it displayed a modest but reasonable easterly fetch about its southern flank as it track eastwards, away from the Australian mainland.

Wind speeds weren’t particularly  strong and the low tracked in an unfavourable easterly direction, and the fetch only spent a brief period aimed nicely within our swell window, so I’m keeping my expectations relatively low from this source - both on timing and size from this source. It’s more likely that we’ll see an increase throughout the afternoon (than the morning) with inconsistent sets in the 2ft range, which should persist into Friday before easing. 

Thursday's winds look very good as a broad trough pushes off the coast (again!) forming a low off the Far South Coast, resulting in moderate to fresh W’ly winds across most regions, ahead of a strong to gale force SW change across the Far South Coast from about mid afternoon onwards (which probably won’t reach the Sydney region until after dark). Just keen in mind that surf size may be a little under spec in the morning.

Friday looks a little tricky. Gale force southerly winds extending around the western flank of the low are expected to push very close to the coast contained within a thin fetch. The surf forecasts models have a lot of size for the middle of the day - 6ft+ sets at south facing beaches - but a lot of this size will be windswell associated with the accompanying local gales. 

The actual wind direction is also difficult to predict across the coastal margin, due to the close proximity of the low to the mainland. Models have SW tending S’ly winds throughout the day but the axis of the low is expected to be near the Sydney/Hunter region early morning, which should create a period of early westerly winds in some locations. Confidence is not high on this scenario but if I had to hedge my bets, I’d put the Northern Beaches at the top of the list, and possibly the Central and Hunter coasts for a brief period around dawn.

As for size, we’ll probably see wind affected 5-6ft sets at south facing beaches throughout the day (reaching a peak early afternoon), with smaller surf elsewhere owing to the southerly swell direction (it’ll be hard to decipher the small underlying E/SE swell). The Hunter coast may however see larger wave heights from the southerly swell. 

In any case, aim for a sheltered southern corner for the best conditions on Friday. 

This weekend (Saturday 24th - Sunday 25th)

Looks like a relatively fun weekend of easing S’ly tending SE swells across the region.

Friday’s large south swell will decline fairly steadily into Saturday but we’ll see a small reinforcing SE swell, originating from a broader E’ly fetch off the southern flank of the Tasman low (aimed more so into the South Coast, therefore resulting in marginally bigger waves from this source, south of Wollongong). 

Early Saturday morning should see 3-5ft sets across most south facing beaches with smaller waves into the afternoon, and conditions are looking pretty good with mainly light to moderate W/SW winds and sea breezes. Exposed beaches may have some leftover lumpiness on the surface but on the whole it’s looking pretty good.

Smaller surf will then prevail through Sunday, with inconsistent 2-3ft sets (a little bigger across the South Coast) but also easing during the day. Conditions look clean with light offshore winds and sea breezes. A very late S’ly change may impact the Far South Coast but it probably won’t reach the Sydney region until the early hours of Monday morning.

Next week (Monday 26th onwards)

Monday’s southerly change will clear quickly to the east, so we may kick off the day with early light offshore winds ahead of an afternoon sea breeze. There won’t be a lot of swell generated behind this change - compared to Friday’s system - but south facing beaches may see some early 3ft+ sets (bigger in the Hunter), with smaller waves elsewhere.  

Also, in similarity to the current Tasman system producing an E’ly swell from its latter incarnation near New Zealand, we’re looking at a similar small E/SE swell for Southern NSW through Tuesday and Wednesday - no major size but probably a little more than we’re expecting on Friday (i.e. maybe some inconsistent 2-3ft sets at exposed beaches). 

Otherwise the mid-week period is looking at easing southerly swell with small conditions and light winds. There are no other major swell systems on the horizon beyond this right now.

See you Friday!