Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Wednesday 30th June)

Best Days: Thursday: fresh NW winds and a small, directional south swell at a handful of south swell magnets. Saturday/Sunday: solid but windy S'ly swell. Sunday morning should have a brief window of good winds early. Tues/Wed: building long period S'ly groundswell, possibly of a reasonable size.

Recap: Preeeeeeety much flat. A few stray lines of south swell but hardly surf able even for the lightweight brigade.

This week (July 31 - Aug 1)

Look at the current conditions this way: at least when it’s flat, it can’t get any smaller.

And it’s also unique from a forecasting perspective because you’re starting off with a clean slate: there’s no residual swell in the water which makes it easier to assess incoming swells on their individual merits.

So, getting straight into the forecast - there’s no major change to the notes issued on Monday. That is: we've got some flukey long period south swell on tap tomorrow ahead of a solid weekend of short range south swell as a front pushes into the Tasman Sea, and more south swell for next week.

The front/low generating Thursday’s impending long period south swell was an impressive beast with 60kt+ winds recorded just south of Tasmania last night. However satellite data shows that the bulk of these winds were mainly W/NW, and I’m now a little concerned that Monday’s forecast may have been a tad too optimistic (of which it wasn’t an especially encouraging outlook anyway). 

However I still can’t discount the sheer size, strength and duration of the westerly belt below the continent, and despite its unfavourable alignment and I still think we’ll see some small, infrequent long period energy make its way up the coast on Thursday. The swell models are certainly picking up this long period energy which adds a little more weight to the overall confidence level.

Only a handful of locations will pick up anything from this event (the Hunter doing the best, as it does under these kinds of synoptic setups); look for very, very occasional 2ft sets at exposed south swell magnets across the greater Sydney region, up to 3ft in the northern Hunter. But with long breaks of flat conditions between sets, and hardly anything else at remaining beaches. Certainly don’t go out searching for something to ride on Thursday because this is a low confidence event (both in its size and timing). The Bondi surfcam will be your best assessment tool of how the swell is performing (I'll try to upload some screengrabs in the comments below).

At least conditions will be clean (if somewhat blustery) with fresh NW winds. 

Friday looks to be a smaller, less consistent version of Thursday (if that’s possible!) with possible a tiny fraction of generally unrideable northerly windswell in the mix at exposed NE facing beaches. Winds will be W’ly throughout the day at strength, so conditions will again remain clean across most beaches. 

This weekend (Aug 2-3)

The Long Wave Trough responsible for this vigorous storm track is expected to move more to the east by the weekend, by which time its western flank should be positioned within our south swell window. This will push a cold front into the southern Tasman Sea early Saturday morning, generating a new short range south swell that’s due to peak overnight. We’ll also see some mid range energy from a secondary fetch much further south (below Tasmania) but the primary source will certainly be the closer system.

Unfortunately, gusty S'ly winds will render most open locations quite bumpy both afternoons - early Saturday morning will see W/SW winds but surf size will be much smaller around this time (the swell is expected to kick in properly late morning/lunchtime).

There’s a reasonable chance that Sunday morning will see early W/SW winds at many locations, which is convenient as wave heights should be strong for the early session - but they’ll swing southerly by mid-late morning, accompanying a dropping swell trend. So aim for the dawn patrol.

Size wise, we’re looking at a peak late Saturday or early Sunday in the 4-6ft range at exposed south facing beaches, with smaller 3ft surf at remaining open beaches, and tiny waves inside protected southern corners. 

Longer term (Aug 4 onwards)

Sunday’s swell will continue to ease through Monday. However, another strong frontal passage - much broader in latitudinal coverage than the current system - is expected to track south of Tasmania early next week, and is expected to generate strong southerly swell for the coast, probably building throughout Tuesday and possibly reaching somewhere in the 4-6ft range at south facing beaches through the middle of the week. More on this in Friday’s update.