Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 27th August)

Best Days: Tues: OK conditions and easing S'ly swells. Wed/Thurs: very large S/SE groundswells across the coast with good winds. 

Recap: Saturday saw easing S’ly groundswell and freshening N’ly winds, ahead of a peaky NE swell that provided fun 2-3ft waves into Sunday. Strengthening southerly winds and building S’ly swells have created a poor day of waves today.

This week (Aug 28 - 31)

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We’ve got some incredible waves ahead.

Tuesday will be between swell events: today’s building energy will reach a peak overnight and then trend down throughout the morning.

South facing beaches should manage 4-5ft+ sets early in the day (smaller elsewhere, though bigger in the Hunter) and although we’ll generally see moderate to fresh SW tending S/SW winds across the coast, some regions (such as the Northern Beaches) should see an early W/SW thru possibly W’ly breeze. It's not worth too much attention but you'll certainly get wet if you're keen.

On Wednesday, a new S/SE groundswell will push through during the morning. It may possibly not be quite there are first light north from the Illawarra, but it’ll start to make its presence felt by mid-morning and as we head into the afternoon it’ll be at full throttle.

This energy will being generated by a deepening Tasman Low that’s due to to intensify well east of Tasmania tonight and into Tuesday morning. There are several key features worth pointing out here that will contribute to what's expected to be an exceptional swell event:

1. This low will be slow moving and working on an active sea state generated by today’s front
2. The core fetch will slingshot around the south-western flank of the low, perfectly within Sydney’s swell window
3. Wind speeds close to the centre of the low are expected to reach 50kts for about a day, and the supporting fetch will be proportionally quite strong
4. The low is ideally placed within Sydney’s short to mid range swell window - far enough away so that the full effects of the low (wind/rain etc) are not felt across the mainland as the swell reaches a peak, but close enough so that there is the least amount of swell decay

Wave heights are expected to peak through Wednesday afternoon and may even hold into Thursday morning; at their height we’re looking at 8-10ft sets across exposed parts of the Southern NSW coast though (relatively) large swell periods associated with this event (15+ seconds) are likely to exaggerate wave heights considerably more across offshore bombies. Protected southern ends will however see much smaller surf as there'll be quite a reasonable percentage of south in the swell direction.

Wednesday’s conditions are looking very good in general with moderate to fresh SW breezes, likely W’ly across some coasts through the morning. Wednesday will be a day only suitable for those surfers will complete confidence in their ability. 

On Thursday, wave heights will trend down though it’s likely to be quite large early morning, perhaps not quite the same size as Wednesday’s late peak but 6-8ft+ sets are possible at south swell magnets early in the day (worth noting that the models are estimating Thursday morning as seeing the most size, but I think  Wednesday’s late kick will likely provide the biggest surf). Winds are looking very good, light offshore with a weak afternoon sea breeze.

Beaches not open to the south will be much smaller - though not quite as small as you’d expect from a straight southerly swell - so there’ll be great waves just about everywhere.

And to finish the working week, wave heights will continue to ease steadily from the S/SE through Friday with winds strengthening from the north as a front approaches from the west. A late W’ly change is possible though current guidance doesn’t suggest anything favourable until the last few hours of the day at the earliest. A small N’ly windswell is also likely but given the S/SE groundswell over the preceding days, I suspect it won’t be of much interest.

This weekend (Sep 1 - 2)

A strong frontal passage over the SE corner of the country will maintain brisk W/SW offshores on Saturday ahead of a brief S’ly change early Sunday, reverting back to the SW at some point into the afternoon.. 

With wave heights reseting to a low point on Saturday, there won’t be many options away from reliable south swell magnets - but into Sunday we’ll see building S’ly swells as the Southern Ocean fronts finally enter our swell window.

At this stage Sunday’s risk of onshore winds is spoiling the outlook, but south facing beaches could very well build from 2-3ft to 4-6ft throughout the day and if this occurs there’ll be options inside protected southern corners. 

More on this in Wednesday’s update. 

Next week (Sep 3 onwards)

This next frontal passage looks pretty beefy. It won’t be ideally aimed for our region but the sheer strength and breadth of each fetch contained within the passage will contribute heavy S’ly swells through the southern Tasman Sea, which should maintain solid waves through Monday and possibly Tuesday, up to 5-6ft+ at south facing beaches (though much smaller elsewhere).

Easing surf is then expected through the second half of next week.