South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Wednesday 19th July)

Best Days: Thurs/Fri: series of solid, windy south swells building across Northern NSW, but remaining only small in SE Qld. Sat/Sun: large clean SE groundswell for Northern NSW, with light offshores. Plenty of fun waves in SE Qld too.

Recap: A small E’ly swell graced SE Qld beaches on Thursday and there’s been some northerly windswell noise in the mix this morning, but otherwise it’s been a tiny to flat couple of days across remaining beaches. 

This week (July 20th - 21st)

A developing Tasman Low will extend a long fetch of S/SW winds across the eastern seaboard over the coming 24 hours. 

As the low anchors itself in the south-eastern Tasman Sea, we’ll see a series of secondary fronts wrap around its western flank, generating several southerly swells for Northern NSW (and to a much lesser degree, SE Qld). 

Essentially, the trend will be up all day Thursday, and up a little more on Friday as a stronger new pulse kicks in. South facing beaches south of Byron will see the most size, reaching up to 4-5ft on Thursday afternoon but the second swell - which may be temporarily undersize early Friday ahead of a strong push through the afternoon - should reach 5-6ft+ at south facing beaches south of Byron.

As per usual, locations without good southerly exposure will be considerably smaller, owing to the steep southerly swell direction. 

Conditions will be best on Thursday under a mainly fresh W/SW breeze, with locations south of Byron tending S/SW on Friday as the associated front clip the coast (however we should see an early W/SW breeze).

North of the border, surf size will be much smaller. I’m not expecting anything of interest on the southern points Thursday - maybe some stray 1ft sets through the afternoon, but bigger (and still clean) at exposed northern ends, possibly 2-3ft at reliable south swell magnets. 

Friday afternoon’s pulse of slightly bigger S’ly swell still won’t do much across the outer SE Qld points (maybe some stray, very inconsistent one-wave 2ft sets) but exposed northern ends should see 3-4ft surf at times - but remember, it'll be smaller through the morning. The Sunny Coast will probably see a little less size than this too as it's even less favourably aligned for acute south swells.

Additionally, there is also a risk that winds will swing S/SW in SE Qld, though it’ll be a little weaker than what is expected south from Byron. So, it may be manageable - but don't get your hopes up. 

This weekend (July 22nd - 23rd)

Whilst Thursday and Friday are motoring along with building S’ly swells, the primary Tasman Low - by this time just off the west coast of New Zealand’s South Island - is expected to reintensify, generating gale to storm force S thru’ S/SE winds that will kick up a large swell for Saturday.

The models have been moving the timing on this around a little over the last 48 hours, but seem to have settled back where we were in Monday’s notes. That is: probably not in the water at dawn on Saturday across Northern NSW (though there’ll still be a strong residual S’ly swell present), then building through mid-late morning ahead of a peak in the afternoon. 

We’ll kick start the weekend with 4-5ft surf across south facing beaches south of Byron (and just a foot across SE Qld outer points, maybe 2-3ft at exposed northern ends). But, as the swell builds through late morning and into the afternoon, most exposed beaches south of Byron Bay should pick up 6-8ft sets by dark, in fact the relatively long swell periods (14-15 seconds) could further exaggerate surf size at offshore reefs and bombies. Protected locations will however be much smaller - but there'll be a lot of water moving around regardless. 

This swell will then trend down from Sunday morning, though first light could be of a similar size to late Saturday. However we’ll lose two or three feet throughout the day. Swell direction will initially be S/SE but it'll slowly veer SE throughout the course of the event.

North of the border, we should see a window of good waves very late Saturday and early Sunday, around 2-3ft across the outer points and bigger near 3-5ft at exposed northern ends. Expect smaller waves on Saturday morning and also as the swell eases into Sunday afternoon.

Even better: a new ridge of high pressure will dominant the coastal margin, creating light variable winds for much of the weekend. Exposed locations in Northern NSW may see a lingering southerly wobble from Friday’s winds on Saturday morning, but it’ll improve throughout the day. Sunday should see light winds all round. 

If I had to pick the pick of the weekend, it’d probably be Sunday morning - this will offer the best conditions, and we’ll be on the backside of a strong but still quality swell event. 

Next week (July 24th onwards)

A strong front will exit Bass Strait overnight Sunday, and should provide a small kick in south swell sometime very later Monday (Lower Mid North Coast) or early Tuesday (remainder of Northern NSW coast). 

We'll see small residual SE swell around the 2-3ft mark at most open Northern NSW beaches on Monday morning, and probably a little more size from the new south swell into Tuesday. 

I don’t think we’ll see anything in SE Qld from this system though.

A powerful polar low tracking behind will north-east into the lower Tasman Sea around the same time, generating an excellent through highly direction long period S’ly swell that’s due to build through Tuesday afternoon, peaking into Wednesday. We could see 4-5ft surf at south facing beaches (south of Byron) from this source. This should generate some fun 2-3ft waves at south swell magnets in SE Qld but the outer points will be small and inconsistent at best, around 1-2ft. 

More on this in Friday’s notes.