Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Friday 29th July)

Best Days: Saturday: small clean leftover south swell. Sun: bigger S'ly swell with light winds. Mon: small clean south swell. Wed/Thurs: tricky, but building S'ly swells, possibly solid. Later Thurs/Fri/Sat: potentially large S'ly swells.

Recap: A new south swell build across Sydney beaches on Thursday, a little earlier and a little bigger than forecast, with sets reaching 3-4ft at south facing beaches. A second, stronger south swell has filled into the coast today and we’re seeing strong 4-6ft sets across south facing beaches this afternoon as the swell reaches a peak, and bigger 6ft+ bombs across the Hunter coast and some outer bombies. However the sets are rather inconsistent, and wave heights are smaller at beaches not completely open to the south. Conditions have been clean both days with light offshore winds. 

Strong lines at Bondi this afternoon

Plenty of size at Manly considering the S'ly swell direction

This weekend (Saturday 30th - Sunday 31st):

Today’s strong southerly swell will ease rapidly overnight, and conditions should be clean for the early session with light offshore winds. A weak front is expected to cross the region during the morning so we’ll probably see winds veer moderate southerly during the day but they won’t have too much strength. A period of light variable winds may play out during the middle of the day before sea breezes develop through the afternoon.

As for surf, the current swell is rather inconsistent and this trend will persist into Saturday. Wave heights are expected to peak this afternoon and trend down overnight; south facing beaches should still manage 2-3ft sets throughout the day (biggest early morning), with larger waves across the Northern Hunter region - however surf size will be much smaller at beaches not completely open to the south. We may also see a slight drop in size throughout the day.

A strong new front pushing into the lower Tasman Sea later today will generate another burst of south swell for the region, which is expected to reach the Far South of the state late Saturday afternoon (though probably no further north than about Ulladulla), before arriving overnight across Illawarra, Sydney and Hunter coasts. 

Our surf forecast model is underestimating the size and strength of this swell, and I think it’ll perform a little better than the data is presently showing, with south facing beaches likely to see 3-4ft+ sets at times on Sunday.  Again, there’ll be much smaller surf at beaches not completely open to the south but conversely, the Northern Hunter should see another foot or two on top of these figures. 

Surface conditions look great on Sunday with light to moderate offshore winds and a chance for an afternoon sea breeze, so get out and amongst it as there should be great waves at many beaches. 

Next week (Monday 1st onward):

A moderate front is expected to track east of Bass Strait on Sunday afternoon, but it’s not modelled to be very strong nor very well aligned within our swell window. Sunday’s south swell will be easing by Monday, so we should see a combination of old facing and new building S’ly swell with perhaps inconsistent 2ft+ sets at south facing beaches (3ft+ across the Hunter) and smaller surf elsewhere. Conditions are expected to be clean under a freshening NW breeze. 

A broad, complex low pressure system is then forecast to develop across the southern Tasman Sea, stretching halfway down to Antarctica, and this is expected to generate some significant swells for the second half of the week.

Prior to this, Tuesday will probably see smaller residual energy - potentially flat at many locations - and freshening offshore winds as the low takes shape. The models currently have a SW fetch developing parallel to the South Coast into the afternoon but right now this is too late to be of any benefit to us. 

In fact, the specifics for next week are a little tricky because right now, the models have the low’s western flank very close to the mainland - if they shunt it a couple of hundred kilometres west (plausible, seeing that we’re still four days from its evolution), then we won’t see much, if any swell from it. 

That being said, the sheer size and magnitude of this system - and its slow eastward track - means it's very likely to develop favourable swell generating characteristics for us next week.

To begin with, we're looking at one or two days of southerly gales off the Southern NSW coast from late Tuesday through Wednesday and probably Thursday. Also, as we progress through the week we’ll also see the southern flank of the low - well south-east of Tasmania - start to come into effect as it slingshots cold fronts around the primary low, generating stronger, better aligned southerly groundswell for the region.

The upshot of this is that we have a series of punchy short range, but flukey south swells on the cards for Wednesday and Thursday, with any time from late Thursday thru’ Friday and maybe even Saturday potentially the target of a sizeable  series of powerful southerly swells. Surf conditions will be windy but the general flow should be out of the western or south-western quadrant, meaning most beaches should be quite workable.

More on this on Monday. Have a great weekend!