South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Wednesday 29th August)

Best Days: Thurs: light winds, large surf in Northern NSW, great outer points in SE Qld. Sat: early morning for clean conditions and steadily easing S/SE groundswell and N'ly windswell. Mon PM onwards: strong building trade swell though with tricky winds.  

Recap: Tuesday was pretty good, with a strong mid-range S’ly swell offering 2ft+ sets across the outer SE Qld points, with bigger waves at exposed northern ends and 4-6ft surf across south facing beaches south of Byron. Wave heights eased into the afternoon and have largely levelled out today with very small waves throughout SE Qld and a steady south swell in Northern NSW, but the Mid North Coast saw a late jump in large, long period S/SE groundswell that’s produced solid surf in the 8-10ft range across Southern NSW, reaching 15ft at offshore bombies (and I ain’t talking face size). We haven’t seen quite that size across Northern NSW yet and it’s yet to materialise across Far Northern NSW and SE Qld but a strong upwards trend will occur overnight tonight.

This week (Aug 30 - 31)

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So far this swell from the Tasman Low has come in very close to forecast expectations, with regards to size and timing through Southern NSW. 

As such, confidence is reasonably high for how this event will pan out across Northern NSW into Thursday, though any energy out of the south always throws a curveball relative to SE Qld. 

Whilst the general consensus under southerly swell events is to half surf size as you head north of the border, and then halve it again (then, if you’re still not very confident, halve it one more time for good luck) - we’ve got a few redeeming factors with this system that should tip the balance back in our favour.

And that is - a sustained, slow moving fetch, working on an active sea state, with sufficient core wind strength to generate much longer periods (than usual) that are likely to maintain much more energy (and size) as they diffract around Cape Byron, Point Danger and Cape Moreton. 

All regions should see clean conditions on Thursday with mainly light variable winds. So, this discussion is really about wave heights - of which there won’t be much of a trend through the day: perhaps an easing across the Mid North Coast through the afternoon, and perhaps a slight lag on peak wave heights across Far Northern NSW and SE Qld early morning. 
 
As such I can’t find any reason to deviate away from Monday’s call, which was 8-10ft sets south of Byron at locations offering good southerly exposure, with a healthy percentage of size across the regional semi-exposed points in Northern NSW (though much smaller at protected southern corners). 

Throughout SE Qld, we should see a peak of 3-5ft surf across the outer points - though there’s a risk of slightly undersized waves early. Exposed northern ends should push north of 6ft+ during the day. If anything, the Sunshine Coast is likely to come in a little smaller than the Gold Coast. And, the sheltered inner points like Noosa really won’t fare very well despite all of positive attributes I discussed above: it just doesn’t like southerly swells. 

Slowly easing S’ly swells are expected on Friday, with a modest secondary fetch around the (decaying) Tasman Low creating some additional mid-period S’ly swell energy for the coast (see below). However we’ll be under a freshening N’ly airstream all day and this will create major problems. 

There is a chance for isolated regions of light NW winds for an hour or two at dawn, but even ten knots is too much for the points so you’ll probably have to aim for the open beaches - which may not cope very well with the strong, sizeable (though easing) long-lined southerly groundswell.

Friday’s northerlies are expected to eventually reach 30kts+ by the afternoon and we’ll see some junky windswell in the mix too around 3ft right on dark (mainly across the southern Gold Coast and Far Northern NSW coast).

This weekend (Sep 1 - 2)

A series of strong fronts will cross the SE corner of the country over the weekend. This will veer Friday’s N’ly winds around to the NW for Saturday morning.

Unfortunately, this is expected to occur before midnight Friday, which is a problem as it’ll shut off the swell supply too early to benefit Saturday: wave heights will be trending down from midnight so by first light Saturday morning there may not be a lot of energy left across the coast. 

Some exposed locations may pick up stray 2ft+ sets but I’m not very confident on this. We’ll see a similar level of leftover S’ly swell at south swell magnets south of Byron but this too will be easing. 

As such, aim for the morning session for the biggest waves, and keep your expectations low. At least it’ll be clean. 

Sunday will start off tiny, with freshening SW tending S’ly winds (lighter in SE Qld) as a front clip the coast. We’ll see building southerly swell through the afternoon at south swell magnets south of Byron (mainly the Mid North Coast) but with these winds there won’t be much to get excited about.

Next week (Sep 3 onwards)

Sunday’s change will clear to the east early next week but a ridge of high pressure over Northern NSW may push fresh E/SE winds across our region on Monday. 

This is a shame as we’re looking at a strong S’ly groundswell across Northern NSW, up to 5-6ft at south facing beaches south of Byron through into Tuesday morning. 

However the positive aspect here is that the ridge will remain stationary for a while and it’ll generate some useful trade swell for our region from late Monday through Tuesday and Wednesday, with size in the 4-5ft range for a few days. Conditions won’t be great but there’ll be decent waves across the outer points and even the sheltered inner points will pick up plenty of size and will offer clean conditions..

It’s worth noting that the models are going a little bonkers now with an unseasonable tropical system supercharging this fetch (10ft out of the E/NE next Thurs? Unlikely…) but the good news is that broadly speaking, a blocking pattern will probably set up camp through the Tasman Sea that’ll lead to an extended period of swell out of the eastern quadrant.

Just one last system to mention - in the event that late next week is downgraded elsewhere - an intense polar low passing well to the south off Tasmania on Sunday (just off the ice shelf - see below) will generate a small but long period S’ly swell that’s expected to reach the South Coast late Tuesday, and the Sydney/Hunter region on Wednesday and Northern NSW late Wednesday and Thursday. Set waves will be very inconsistent and the models aren’t picking up this swell very well - but we could see anywhere from 3-5ft at south facing beaches and possibly bigger sets at well aligned offshore bombies.

See you Friday!