Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 31st July)

Best Days: Tues onwards: building S/E tending SE swells, biggest and best Wed PM. Thurs will see plenty of swell but with tricky winds.  

Recap: The weekend played out pretty much as expected - strong south swell early Saturday with 3ft sets across Sydney’s south facing beaches and smaller surf elsewhere (though bigger in the Hunter). Wave heights eased a little into the afternoon but more rapidly overnight, leaving us with very small, easing surf conditions through Sunday. Today has maintained tiny waves across Southern NSW. 

This week (August 1st - 4th)

A low is developing off the South Coast, and will be our primary source of swell for the next few days.

However, it doesn’t look especially crash hot on paper. Initially, a thin fetch of S’ly gales developing along its western flank will strengthen, and then rotate outside of our swell window. This will generate a brief flush of S/SE swell but it’ll be aimed mainly towards locations north of Sydney, and will likely result in a brief up and down in the size department.

With moderate to fresh SW tending S/SW winds across the Southern NSW coast, those beaches picking up most of the size won’t be terribly clean either. 

It’ll probably be small early Tuesday morning but should begin building rapidly throughout the morning, probably reaching 3-4ft at south swell magnets by early-mid afternoon (a little bigger across the Hunter) but it’ll be much smaller at beaches with less southerly exposure, and also to the south of about Wollongong.

At the same time we’ll see some short range S’ly swell - probably of a similar size - fill into the coast, originating from the accompanying S/SW fetch developing between the low and the mainland. This will only favour south swell magnets.

A better secondary S/SE fetch is expected to develop across the southern flank of the low later Tuesday, and this will provide a more useful mid-range swell through Wednesday and Thursday. There may be a temporary period between swells (perhaps early Wednesday) but most open south facing beaches should see 4ft sets through this time period, with bigger waves across the Hunter. Again, expect smaller surf at beaches that are not directly open to the south.

More crucially, local winds will quickly relax mid-week as the low moves eastwards, away from the coast, so we’re looking at light variable winds on Wednesday (possibly a lingering SW flow across the Hunter, but improving during the day). This is the pick of the forecast period - mainly Wednesday afternoon, as there’s a better chance that the swell will be in by then, compared to the morning.

Thursday will see plenty of surf across the region but a developing coastal trough will bring a heightened risk of developing NE tending N’ly winds during the day. A gusty W/NW wind change is expected late afternoon or early evening but right now, much of Thursday looks dicey in the wind department. We may also see some local NE windswell in the mix too by the afternoon. I'll firm up the specifics on Wednesday.

This next trough is expected to develop into a surface low east of Sydney but all indicators are that it’ll be poorly aligned for our coast and won’t generate much, if any swell. 

As such, it looks like Friday will see clean conditions with moderate W’ly winds, and a small combo of easing S/SE swell (from Thursday) and a minor mid period E’ly swell, originating from a secondary fetch exiting western Cook Strait over the coming days, in conjunction with the Tasman Low (see below). However, sets will be very inconsistent, perhaps 2ft at swell magnets and long breaks between ‘em. 

This weekend (August 5th - 6th)

Saturday looks pretty small at this stage. The mid-period swell due Friday should persist into Saturday morning with very infrequent 2ft sets tailing off throughout the day. Offshore winds are expected to reach gale force strength as a vigorous front crosses the coast.

These gales are expected to be quite W’ly in direction through Bass Strait, even W/NW if anything - so our favourite flukey source of south swell is a low confidence game at this point in time, for Sunday that is.

I certainly wouldn’t rule it out for now, as it’ll only take five or ten degrees to suddenly make a big change in the outlook - but right now chances are that most Southern NSW beaches will be pretty small on Sunday.

Next week (August 7th onwards)

A large, slow moving deep low pressure system in the Southern Ocean linked to the weekend’s fronts will finally push into our swell window around Monday, which should give rise to a couple of days of strong southerly groundswell through the first half of next week. More on that in Wednesday’s update.