Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Wednesday 4th September)

Best Days: Thurs: fun E'ly swell with generally OK winds. Fri: mid-late a'noon NE windswell with a W'ly wind change. Sat: large building S'ly swell, but very windy. Sun: large, easing S'ly swell, fresh offshore winds. Mon/Tues/Wed: more sizeable S'ly swell, but windy. 

Recap: We’ve had a couple of great days of E’ly swell, generally in the 3ft+ range at most open beaches though with a few periods punching slightly above this near 3-4ft+. Conditions have been clean with offshore winds and light afternoon sea breezes.

Nice runners at Manly this morning

Fun waves on the Cenny Coast this morning

This week (Sep 5 - 6)

Thursday is looking pretty good, though you’ll have to make it early, as we’re expecting surf size to ease throughout the day.

The fetch responsible for our current swell was still active late yesterday, which means we’ll see continuing surf into Thursday though with a slight weakening trend into the afternoon. Tomorrow morning should still manage 3ft+ sets at exposed beaches, but size will gradually through the day and early light offshore winds will swing into an afternoon sea breeze, deteriorating wave quality.

A little less size is expected Friday with a more pronounced easing trend during the day - perhaps a few stray 2ft+ sets first up at dawn - but easing to 1-2ft as the morning wears on, and it’ll be noticeably weaker too. 

However, the fly in the ointment on Friday morning are the local winds, thanks to the approach of a deepening trough from the west. This will actually swing winds around to the NW then W into the afternoon - strong to gale force - but the morning looks to see freshening N/NE winds across the coast

In fact, the late session is shaping up to be OK as a strengthening NE infeed into the trough will building local NE windswells that will reach a peak at the same time the wind shifts offshore. No major size is expected, but some of the more reliable NE swell magnets could pick up 2-3ft sets by the afternoon (bigger south from the Illawarra due to the longer fetch length, with more strength).

Winds look like they’ll tend NW between 12-2pm, and then veer strong W’ly around 3-4pm, so later will be better on Friday.

This weekend (Sep 7 - 8)

Strong S/SW winds will develop off the Southern NSW coast on Saturday as a deep low forms east of Bass Strait. We’ll see strong to gale force W/SW winds locally, accompanying a building S’ly swell that will offer a wide range in size due to the swell direction thanks to to incredibly strong, thought poorly aligned core winds of 50-60kts pushing up through the south-western Tasman Sea (see below).

South swell magnets could easily push north of 6-8ft late Saturday or early Sunday but it’ll be a lot smaller at beaches with less southerly exposure. It’s really hard to have confidence in how much size we’ll see because the strength of this system would ordinarily suggest very large waves (10-12ft) but its poor alignment will shave off a considerable degree of size. In fact, Northern NSW will probably see the biggest waves from this swell despite being geographically further from the swell source.

Saturday looks a little too wild for my liking, with rising swells and strong winds, so Sunday will be a better bet as we’ll see easing (though still fresh) W/SW thru’ SW winds and large, powerful south swell at exposed beaches - but much smaller surf at protected ends. And the trend will be downwards throughout the day. 

Let’s fine tune the specifics on Friday.

Next week (Sep 9 onwards)

Another strong front will push through the Western Tasman Sea on Monday, but this system will extend much further south (see below), resulting in a longer swell event - building into the afternoon, peaking Tuesday, then easing Wednesday. 

This system will also create strong local winds, but they’ll be more from the SW thru’ S (instead of the weekend’s pattern from the W/SW thru’ SW), so only sheltered corners will be worthwhile. At this stage a peak in the 6-8ft range is quite likely. 

More on this in Friday’s update.