Small for a bit, then a return to strong S'ly energy

Ben Matson picture
Ben Matson (thermalben)

Sydney Hunter Illawarra Surf Forecast by Ben Matson (issued Friday 30th July)

Forecast Summary (tl;dr)

  • Tiny weekend of waves, just small peripheral sources
  • Small S'ly swell Mon, not much in it
  • Minor E/NE swell Tues, increasing fractionally Wed/Thurs
  • Building S'ly swell Wed PM, peaking Thurs with chance for some strong sets, size easing Fri
  • Better S'ly groundswell potential next weekend/early in the following week


Tiny leftovers for much of Thursday preceded a small flush of south swell across the South Coast during the afternoon that arrived around dinnertime in Sydney, and peaked overnight. Wave heights this morning were at the lower end of expectations (2ft south facing beaches against a forecast of 2-3ft), though size has maintained through much of the day. Elsewhere it’s been a lot smaller though the Hunter has seen bigger sets in the 3ft range. Conditions have been clean with offshore winds.

This weekend (Aug 1 - 2)

There’s not much surf expected this weekend. 

Today’s south swell will fade overnight, leaving us with residual surf in the 0.5-1ft range at south swell magnets, perhaps the odd bigger set across the Hunter early Saturday morning. 

A small distant E/NE swell will filter in over the weekend from a distant tropical depression way out near Tahiti last weekend, but no major size is expected, perhaps the odd 1-1.5ft set if we’re lucky both days, and extremely long breaks between sets. It’s not worth working around.

As for conditions, we’ve got freshening NW winds for Saturday and early Sunday as a front approaches, which will bring about a SW change on Sunday afternoon. Saturday afternoon may see the wind veer more N’ly and pick up in strength, which will confine the only clean waves to sheltered northern corners.

Next week (Aug 3 onwards)

The first half of next week is looking similarly small. 

Sunday’s frontal passage across Tasmania doesn’t have a lot going for it. It’ll be quite zonal in orientation (west-east aligned), travelling rather quickly, and with very little southerly component to the core fetch exiting eastern Bass Strait. We may see some slow 1ft, perhaps 1-2ft sets at south facing beaches on Monday (a little bigger through the Hunter) but I don’t think there’ll be much in it.

We do however have some small east swell on the way from Tuesday onwards. 

A broad tropical low out near Tahiti this week (responsible for a tiny pulse of E/NE swell this weekend) is expected to provide a peak in long range, inconsistent E/NE swell around Tuesday or Wednesday.

Additionally, a large multi-centered low developing north of New Zealand today is generating a thin though strong E’ly fetch on its southern flank (see below). The broader system is tracking unfavourably eastwards, though it has slowed in the latest model runs which has improved its chances for swell generation. 

As such, I’m expecting a minor increase in E/NE swell on Tuesday (1ft, maybe 1-2ft), building a smidge to 1-2ft+ Wednesday and probably Thursday. I don’t want to get too interested in this swell as most of the fetch will develop just inside the swell shadow of New Zealand, but the models are suggesting swell periods could push into the 12-13 second range (Thursday) and this could nudge wave heights a little higher than my expectations. 

But, let’s play it down and expect small inconsistent surf at best.

In any case, Tuesday and Wednesday will both be nice and clean with moderate to fresh W/NW tending W/SW winds as a series of vigorous fronts pass across the south-eastern corner of the country.

Once again these fronts will be detached from the polar flow, so our south swell will largely remain inactive. However W’ly gales exiting eastern Bass Strait overnight Tuesday into Wednesday should build a small S’ly swell later Wednesday afternoon in the 2ft+ range at south facing beaches, with 3ft+ sets across the Hunter. Don’t expect much size before lunch though.

Thursday has a decent south swell on the cards, from a developing Tasman Low at the tail end of the aforementioned frontal passage (see below). I have a feeling future model updates will whisk this off to the east a little more quickly than we want, but right now Thursday’s on track for 4-5ft sets out of the south (5-6ft+ across the Hunter) and moderate to fresh W/SW tending SW winds. Easing S’ly swells are then expected into Friday.

The longer term model guidance isn’t very promising in the surf size estimation department, but there’s a suggestion for a series of powerful Southern Ocean lows well below Tasmania which should - at a minimum - set up a decent S’ly groundswell for the second half of next weekend and the start of next week.

More on this in Monday’s notes. Have a great weekend!


sean killen's picture
sean killen's picture
sean killen Friday, 30 Jul 2021 at 6:20pm

Cheers Ben some thing to look forward to

MrBungle's picture
MrBungle's picture
MrBungle Friday, 30 Jul 2021 at 7:51pm

The last 2 weeks have been a bit of a reality check. At least there’s a bit of potential.

FrazP's picture
FrazP's picture
FrazP Friday, 30 Jul 2021 at 8:49pm

Liked you better a few weeks ago Ben when the swells were coming! Crowds and small surf, bluhhh.

Easier to keep the covid lock down beverage intake in check when you know there's swell coming.