Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 21st February)

Best Days: Wed/Fri: large to very large long period S'ly groundswell with generally light winds. Tues/Thurs/Sat: medium size S'ly surf (between main swell events) with good winds excluding Tues PM. Sun: Another solid S'ly swell, though smaller than the last few. 

Recap: There’s been stacks of southerly swell over the last few days. Saturday saw 3-5ft sets across Sydney’s south facing beaches with a few bigger bombs reported elsewhere, but size eased throughout the day. A reinforcing S’ly swell maintained 3ft sets at south facing beaches into Sunday (slightly bigger on the Hunter) whilst a marginally bigger third swell pushed through into today, increasing south facing beaches to 3-4ft whilst providing bigger waves throughout Newcastle once again. Offshores maintained clean conditions throughout.

Today’s Forecaster Notes are brought to you by Rip Curl

This week (May 22 - 25th)

We’re in the midst of a strong autumnal south swell pattern, with no signs of any let up in the near future. In fact it looks like we’re going to go up another gear or two as we progress into the end of the week and beyond, related to a slow moving node of the Long Wave Trough.

We’re staring down the barrel of back-to-back long period southerly groundswells, each offering varying levels of size, period and degrees of southerly direction. Initially, Tuesday should see continuing mid-range energy from a persistent SW fetch exiting eastern Bass Strait for the last day or so (similar to the surf we’ve seen today; say 3ft+ south facing beaches in Sydney and 4-5ft across there Hunter), but it’ll be overshadowed by a stronger S’ly groundswell into the afternoon, generated by a powerful front rounding the Tasmanian corner today.

This front is displaying very strong winds in excess of 40-45kts but more impressive is the length and fetch of the width, its relatively slow core forward speed (for a Southern Ocean front) and a slight meridional (north-south) tweak in its alignment through the lower Tasman Sea as we head into Tuesday.

Initially, Sydney beaches should see a building trend from the head of the fetch into Tuesday afternoon (earlier down south) that’ll ratchet up wave heights by a foot or two - but this is by no means the strongest part of the system: Wednesday morning is looking at an almighty pulse of powerful long period southerly swell that’ll light up south swell magnets with very big surf in excess of 6-8ft+. I think our surf model is pretty close to the mark with this one though it’s got the peak into the afternoon, whilst I think it may occur a little earlier (that being said, it’ll remain large all day). I reckon we’ll see some very large waves ridden at some of the more reliable offshore bombies well above this height prediction too (i.e. pushing 8-10ft+). 

The other points of interest for Tuesday and Wednesday are the winds: Tuesday should see early W/SW winds swinging S/SW into the middle of the afternoon (earlier down south) as the edge of the front clips the coast. This should clear Wednesday to a light variable pattern with afternoon sea breezes, though some regions north of Sydney such as the Hunter may see a lingering southerly through the morning. 

And just on wave heights: it’ll be much smaller at beaches that don’t face south, and it’s common to experience a wide variation in size from beach to beach, depending on exposure and bathymetry (as per Craig’s excellent article from last week Analysis: The long and the short of long period swells). But no matter how you slice it, Wednesday is looking pretty big and beefy so even protected spots should have workable waves. 

It doesn’t end there. 

Thursday will see a rapid drop in size from Wednesday, though still remaining elevated across south facing beaches with sets around 4-5ft (bigger across the Hunter near 6ft+). Surface conditions should be quite clean with light variable winds and light afternoon sea breezes. Beaches not directly open to the south will be much smaller.

Whilst this is happening, an even more powerful Southern Ocean low will have developed south of Tasmania, and is expected to slingshot through out far southern swell window, broadening and lengthening an impressive fetch of storm force SW winds through the southern Tasman Sea into Thursday morning. 

If anything, this swell looks a little better on paper with stronger core winds, though it’s alignment isn’t quite as good as the fetch generating Wednesday’s swells. This will translate to larger swell periods but with slightly less ocean size at the coastal margin - arriving Friday, becoming largest into the afternoon - which will probably in turn exaggerate the variation in wave heights across the coast even more from our mid-week event. 

So, those handful of offshore bombies and other reliable locations that accentuate long period south swells particularly well should be larger again - perhaps north of 10ft+ at times - but regular south facing beaches will probably max out in the 6ft+ range, whilst everywhere else comes in much smaller. Again, I need to reiterate the fact that there'll be large discrepencies in wave heights from coast to coast. Despite being a stronger system, this swell won't be aimed as well for Southern NSW and so this time around, a smaller percentage of locations are likely to pick up the bulk energy.

Friday’s winds look really good too under a slack pressure gradient, just light and variable. 

So, in summary - Wednesday and Friday are your biggest days this week. Great conditions are expected most of the period except late Tuesday and maybe early Wednesday at a few spots. 

This weekend (May 26 - 27)

Friday’s large southerly groundswell will ease slowly through Saturday though remain very solid across south facing beaches. Early sets should still be up in the 4-6ft range but it’ll abate to 3-4ft throughout the day (expect another couple of feet across the Hunter). Light winds are expected to maintain smooth conditions.

Into Sunday, yet another long period S’ly swell will grace the coast but this time ‘round it’ll be from a less favourably aligned system pushing through the south-eastern corner of the lower Tasman Sea (plus a little further south in latitude) so we’ll see smaller size than our last few long period swells. 

That being said, it won’t be small by any measure - back up into the 4-5ft range at south facing beaches and 6ft+ across the Hunter throughout the day. A slow moving ridge of high pressure should maintain light winds across the coast. Surf size will once again be smaller at beaches wit less southerly exposure.

So yeah - a steady diet of nothing but southerly swell.  

Next week (May 28 onwards)

This entire progression of southerly swells - related to a slow moving node of the Long Wave Trough - will migrate to a position off New Zealand’s East Coast next week, whilst our Tasman swell window shuts down for a brief period. We may see some flukey long range SE swells from this LWT pattern but there’s nothing noteworthy on the long term carts at this stage.