Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Friday 7th August)

Best Days: Sat: peaky mix of swells, improving conditions. Sun: generally good winds (mainly early, with an a'noon risk of onshores) with strong building E'ly swells. Tues: light winds, strong but easing surf. Small and clean Wed. 

Recap: Gotta admit, it’s been a frustrating couple of days of intermittent south swell. The erratic pulse expected on Thursday initially pushed nicely through the morning then fizzed into the afternoon. Early offshore winds swung S/SE through the afternoon. The next pulse of S/SE swell due today has taken longer to get up and running than expected; initially the morning was only 3ft at south facing beaches but we’ve finally seen a lift this afternoon to 4-5ft. Early light winds went moderate to fresh E’ly through the middle of the day (between 10am and 2pm) but backed off mid-afternoon to become light and variable, even offshore (see Queensy images below from 4pm). 

Solid S/SE sets at Queenscliff this arvo (second image for size reference)

This weekend (Aug 8 - 9)

Yet another complex synoptic chart is creating headaches for the Friday forecast, but here we are. Let’s get into it!

A deepening trough along the coastal margin will spin up a surface low off the South Coast over the weekend. We’ll see a myriad of conditions over the short term period, but for the most part we’re looking at light and variable or offshore winds across Sydney, Hunter and possibly Illawarra coasts both Saturday and Sunday. This is all thanks to the axis of the trough that’s expected to be positioned near or just south of the Illawarra, so to its north, winds will outflow from the west.

Of course, small deviations in its position could change this, but I’m reasonably confident that overnight NE winds (tonight) should clear to the southern region before dawn, and therefore conditions will slowly improve. Sunday is at risk of gale force S/SE winds spreading up the coast - though if this eventuates, it’ll occur into the afternoon (and not the morning). I'll comment below over the weekend if more information comes to hand that's useful.

As for surf, today’s S/SE swell will ease into Saturday though we'll see a slight reinforcement from a secondary front that raced through the lower Tasman Sea today. This should maintain 3-4ft sets at south facing beaches (a little higher through the Hunter) though much smaller options elsewhere.

An overnight NE fetch associated with the developing trough will generate some small local windswell for Saturday, perhaps offering occasional 2-3ft for a period sets at times. It's not a high confidence source though.

Strengthening winds across the southern flank of the trough (and eventual low) south of the Illawarra will steadily building E’ly swells all weekend - becoming quite large though wind affected along the South Coast into Sunday.

Fortunately, we’ll see a spread of the same energy across northern regions, albeit a little smaller in size. Swell direction should hold E/SE and should reach 3ft by late Saturday, increasing from 3-4ft early Sunday to 4-6ft by the end of the day (this is more than model guidance is suggesting).

For what it’s worth, as you head south from the Illawarra, surf size will increase - probably somewhere into the 6-8ft range throughout Sunday at exposed spots - though local winds will become dicier (and ultimately, onshore once you reach the Far South Coast).

So, keep an eye things but we’re looking at a building day of waves with generally favourable conditions. There is a chance the developing low could meander north and bring a temporary burst of S/SE winds to the Illawarra and maybe Sydney region, but it's unclear whether this will eventuate. 

Next week (Aug 10 onwards)

The strengthening trough-cum-low doesn’t look amazingly strong on paper, but its stationary position over the weekend and its close proximity to the mainland will enhance wave heights quite a bit into early next week. 

Exposed spots should push an easy 6-8ft+ into Monday, though with strong to gale force S/SE winds. There’s a chance for a brief of early W/SW thru’ SW winds across a few locations though this will likely be confined to the Hunter, if anywhere.

The low will quickly push NE into Tuesday and we’ll see a correspondingly rapid drop in size through the day, possibly 4-6ft early but likely down to 3-4ft by the end of the day. Light variable winds will allow conditions to clean up relatively quickly too.

During this time frame we’ll also have an undercurrent of long period S’ly swell in the water. The models have shifted the associated storm track (over the weekend) and little less favourably to the east, so size prospects have been pulled back, and in any case the local energy will be more dominant anyway - but south facing beaches should pick up a peak later Monday and into Tuesday around 3-4ft, easing slowly into Wednesday along with the by-then-SE-tending-E’ly swell, which should maintain 2-3ft+ sets at open beaches.

So, Wednesday looks fun for the open beaches, banks pending.

The long term period has an interesting trough for the lower Tasman Sea later next week, which may result in some really nice SE swell next weekend - but that’s a long time away. 

Have a great weekend, see you Monday!