Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Fri 25th Aug)

Features of the Forecast (tl;dr)

• Light/variable winds for the weekend, tending more SE on Sat, NE on Sun
• Small swells both days with stronger long period S swell in the mix on Sun
• Another S swell pulse Mon
• Light winds to start next week, NW tending NE in the a’noon
• Small blend of S and NE-E/NE swells for Mon, a notch bigger Tues/Wed
• Moderate S swell pulse likely Fri, check back Mon for updates
• Still tracking potential E’ly swells but model runs are wishy-washy

Recap

Small S swells yesterday were in the 2-3ft range, bigger 3ft on the Hunter. A brief window of clean conditions north of the Harbour with morning  W/SW winds eluded other locations which were wind affected by a S’ly flow. Winds laid down in the a’noon as pressure gradients rapidly eased. S’ly groundswell was late to show but is in the water this morning with some inconsistent 3ft sets at S facing beaches, bigger 3-4ft on the Hunter and widespread clean conditions with a morning offshore W-NW flow, expected to tend to light N’ly breezes through the day. 

Long period S swell lighting up the Hunter

This weekend (Aug 26-27)

No great change to the weekend f/cast. A pair of troughs remain inland as a large high approaches. That slightly stalled pattern should see a light/variable flow both days with a morning W-SW flow Sat tending to SE-NE breezes in the a’noon.

Sun should see light W-NW breezes tending E/NE-NE in the a’noon. Expect a bit of variability in winds but they should stay light enough to work around without too much drama.

Not much size for Sat, especially through the morning after todays pulse dies down overnight. A few stray 2footers at S facing beaches, tiny elsewhere. Period charts show another pulse heading up the Tasman Sea, which may show late in the day (more likely south of Sydney/South Coast) so it’s worth a look late for some potential new long period S swell to 2-3ft.

Sun looks a better bet for long period S swell. A mix of long period S swell trains should supply 3ft sets, bigger on the Hunter. Through the a’noon some shorter period S from the weaker head of the fetch which pushed into the Tasman makes landfall, adding a bit of consistency but no real extra size.  A weak S’ly flow around the southern extremity of the trough line is likely to see S’ly winds south of Jervis Bay, for anyone thinking about burning fuel on Sun a’noon. Elsewhere, light/mod N-NE seabreezes kick in Sun a’noon.

Next week (Aug 28 onwards)

We’ve still got the basic building blocks in place that we mentioned on Wed with the proviso that everything looks a little weaker and disjointed. High pressure moves NE of Tasmania and the troughs remain inland, although we may see a weaker trough area move off the North Coast of NSW early in the week. 

We should see light winds continue into Mon, with morning NW winds and a’noon NE seabreezes. S swell from the last polar low to transit the lower Tasman pushes surf up into the 3-4ft range at S facing beaches with small amounts of NE-E/NE swell starting to fill in through the a’noon from winds feeding into the trough. Traces of long range E swell from a fetch in Tahitian longitudes early this week are unlikely to add more than the occasional 2ft set, if at all.

Similar conditions for Tues and into Wed, at this stage. Light winds with a N’ly bias both days. Small amounts of S swell Tues to 2-3ft at S facing beaches, easing into Wed.

Local NE-E/NE swell will linger in the 2ft range but we’re still a chance to see an upgrade in size if winds increase into the trough, or any short range trough feature moves into the Tasman, focussing winds. We’ll pencil in 2ft surf for Tues, with 2-3ft on Wed from this source and adjust on Mon if needed. It’s not going to be a significant swell is the bottom line at this stage.

A wind change is likely Thurs as a front arrives and interacts with the lingering trough line, with winds tending NW-W before a S’ly change. 

The S’ly change is associated with a trough of low pressure forming in the Tasman, which now looks much weaker than Wednesdays model runs. Under current modelling we’re looking at developing S swell on Fri in the 3-4ft range, easing back over the first weekend in September. We’ll see how that looks come Mon and hope for an upgrade. 

Convective activity in the South Pacific around a trough between the Solomon Islands and Fiji may drift into the Eastern swell window late next week, potentially forming a useful E’ly fetch north-east of the North Island on the weekend. Models have been wishy-washy over this development so we’ll flag it for now and see how it looks come Mon. 

Seeya then and have a great weekend!