Solid, easing swell over the weekend; good southerly swell early next week

Ben Matson picture
Ben Matson (thermalben)

Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Friday 22nd May)

Best Days: Sun: good winds and abating S'ly swells. Mon: small S'ly swell and light winds. Tues: small to moderate S/SE groundswell with generally favourable winds, swell easing Wed with good winds.  

Recap: Well wasn’t that a surprise package? Thursday’s tiny conditions and this morning’s small south swell with early W/SW winds played out as expected, but this afternoon’s rapid increase in short range S/SE windswell has been nothing short of phenomenal, easy 8ft+ sets at south facing beaches in Sydney and 10ft+ across the Hunter Coast. Winds are storm force S’ly so conditions are unrideable away from the most protected southern corners. This afternoon’s size is all the more surprising given recent model guidance, which never really showed any considerable strength in the surface wind field in our immediate swell window. 

This weekend (May 23-24)

No major changes to the weekend forecast, except for a minor upgrade for early Saturday - today’s very large south swell will ease rapidly overnight. The low that generated it has already exited our swell window and there’s only a moderate trailing southerly fetch in the southern Tasman Sea, so we’ll see steadily abating wave heights throughout the day. 

Furthermore, surface conditions won’t be very good thanks to a fresh lingering southerly breeze. One or two regions (i.e. the Northern Beaches) may see an early period of SW winds across the region, but in general most spots will be ruined by the southerly flow. Exposed south facing beaches should manage 4-6ft sets early morning, before easing to 3-4ft during the day, and it’ll be much smaller at locations not open to the south (and probaly smaller in size south of about Wollongong, owing to the original source region of the swell). However, the Hunter coast should see some bigger waves. 

On Sunday, we’ll see much better conditions as winds veer to the W/SW, and wave heights continue to drop. Most south facing beaches in Sydney should see 2-3ft+ sets throughout the day (thanks to a minor reinforcement of small new S’ly swell), and it’ll be a little bigger in the Hunter but again, directional differences will create smaller waves at beaches not completely open to the south. The upside is that surface conditions should be relatively smooth, save a few leftover lumps and bumps at exposed spots in the morning.

Next week (May 25 onwards)

Our southern swell window will remain the key focus area for the first half of next week. A series of poorly-aligned but very active fronts over the weekend will generate a small to moderate south swell for Monday and early Tuesday, with south facing beaches likely to see inconsistent 2-3ft waves (bigger in the Hunter) and light variable winds should maintain clean conditions.

On Tuesday afternoon, a much stronger pulse of S/SE groundswell is expected to arrive, generated by an intense polar low developing well south of New Zealand late Saturday, that’s modeled to slingshot its way into the broader frontal stream tracking north-east. I mentioned this fetch in Monday’s notes, but the models downgraded it on Wednesday so I correspondingly pulled back forecast wave heights. However they’ve since strengthen the low considerably, with core winds expected to reach 60kts (!). As this fetch will be working on a very active sea state, it should have no trouble generating an excellent pulse of quality groundswell.

This energy is expected to be in the water after lunch on Tuesday (not quite sure on the timing at this stage) and should provide occasional 3-5ft sets at south facing beaches; some swell magnets (such as the Hunter Coast) and offshore bombies are likely to see much bigger surf from this source, however expect smaller waves away from south facing locations. Local conditions look generally good with light offshore winds however there is some concern that a weak front crossing the region may bring a shallow southerly change to some coasts during the day. I’ll take a closer look at this on Monday.

Beyond Tuesday, it looks like we’ve got a period of easing southerly swell across the region as a large high dominated the Tasman Sea, steering the storm track away from our southern swell window. But with very little activity expected in other swell windows, we could be looking at a spell of small surf later next week and into the weekend. More on this on Monday.


mitchvg's picture
mitchvg's picture
mitchvg Monday, 25 May 2015 at 12:45pm

Good period and long-ish lasting swell, for what it looked on the charts I reckon. Were you expecting that?

thermalben's picture
thermalben's picture
thermalben Monday, 25 May 2015 at 12:53pm

Nah, much bigger than expected both Saturday and Sunday, and Saturday morning had good winds for a broader region (and longer time) than forecast. A little surprising to be honest, given the way the low developed on Friday.

mitchvg's picture
mitchvg's picture
mitchvg Tuesday, 26 May 2015 at 8:54pm

Yeah cheers. If the Sunny Coast is the Sunny Hoax, then the Northern Beaches should be dubbed the Northern Teasers!