Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Mon 20th June)

Forecast Summary (tl;dr)

• Temp period of smaller surf Mon; late pulse of mod, mid period SE swell
• Building Tues, then a little more Wed from the E/SE
• Strong E’ly pulses from late Wed thru' Thurs, easing Fri
• Clean all week with light offshore winds
• Tiny surf expected next weekend
• Monitoring potential low pressure development from mid next week, stay tuned for updates.

Recap

Long period S/SE groundswell kicked hard Fri a’noon and maintained plenty of size into Sat with fairly broad coverage of 4-6ft surf under light W/SW winds that shifted SSW to S through the day. Sunday eased back a few notches with 3-4ft surf on offer across the region, becoming slow through the day. Conditions were clean early with offshore winds, before a strong S’ly flow south of Sydney and a lighter more variable flow north of the Harbour. 

Size has eased further today, with a brief period of clean conditions presiding over easing 2-3ft surf, before a SE flow turned it a bit scrappy at most places. 

After the incredibly active start to June with back to back extended S swell events we’ll be turning our attention to the Eastern quadrant this week. Details below.

Eased off today and a bit scrappy

This week (June 20-24)

We’ve got a nice chunky 1033 hPa High slow moving at very southerly latitude, roughly triangulated between Tasmania and the South Island. As well as a precursor SE fetch adjacent to the South Island it is now squeezing pressure gradients with a compact, but deep low, which is currently forming gale force fetches out of Cook Strait and just north of the North Island. The North Island fetch is better aligned and aimed at sub-tropical regions but will still supply swell for the entire f/cast region.

In the short run, surface conditions should improve quickly as a front followed by a high moving through the interior bring a return to a weak synoptic environment which should bring a mostly light offshore flow through the day, possibly tending NW in places. Mid period SE swell from the precursor fetch will hold surf at roughly the 3ft mark, with an improvement in quality noticeable. Should be some fun beachbreaks around.

Wednesday sees an under-sized start as the mid period SE swell eases back a notch. By mid-morning we’ll see an increase in size from the Cook Strait source, with sets up to 4ft and a marked increase in period boosting quality and power. Conditions should be mint early under a mod W’ly  to W/SW synoptic flow, but winds will clock more SW to S through the day, although without much strength. A late evening glass off is definitely on the cards as winds drop out.

Through to the latter part of the week and Thurs sees another pulse of E swell, with Wednesdays pulse fading out through the morning to be replaced by a more E’ly swell, likely showing by mid-morning to lunch-time, again maxing out in the 4ft range. Winds will be just about perfect: light W’ly, possibly trending W/NW in places. With high pressure over the Mid North Coast, and a light offshore flow from there to the Vic border it will be a nice day to get in the water.

End of the working week sees another day of offshore winds, mostly straight W’ly. Perfect to make the most of a dying swell. Expect a few 3ft sets early, with size easing through the day, back down to the 2ft range by close of play.

This weekend (June 25-26)

Very quiet weekend of waves ahead, so if you’ve got dings to fix or lawns to mow it’s looking good for that.

We’ll be well and truly on the other side of this E swell by Sat and there’ll be just a couple of stray 2ft sets on offer across open beaches, becoming less consistent through the day. Perfect for learners and a slide on a log.

Sunday looks even smaller with size really bottoming out into the 1-2ft range or less during the day.

Conditions will be pristine both days with light offshore winds on offer as high pressure at northerly latitudes and weak fronts supply dreamy conditions. 

Next week (June 27 onwards)

Not much action to start next week. Monday looks tiny with light winds from the W early, tending S’ly as a small, troughy low forms off the coast.

That should see an onshore pattern develop into Tuesday with the trough sitting on top of a high moving into the Tasman and a small increase in short period SE-ESE swell and winds from the same direction.

Into the middle of next week and there is a lot of instability expected. Anther broad, troughy area of low pressure may form off the North Coast or SEQLD, possibly coalescing into a more substantial surface low later next week, although with uncertain surf potential at this stage.

There’s also another cold front and very strong low expected to enter the lower Tasman during this period, possibly generating a solid S swell or even interacting with the more tropical derived surface low we just mentioned and forming a deep low off the Southern NSW Coast (see below).

To be honest, it looks quite explosive so check back in on Wed and we’ll update the prognosis.

Seeya then.