South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Monday 23rd December)

Best Days: Tues: large, long period S'ly swell in Northern NSW (much smaller in SE Qld). Easing from the a'noon onwards. Wed: smaller leftovers, including a small residual E'ly swell. Thurs thru' Sun: fun trade swell, biggest in SE Qld over the weekend. Mon onwards: new cyclone swell, peaking New Years Day or thereabouts.

Recap: A small E’ly swell provided fun waves within brief windows of favourable winds over the weekend. Saturday morning offered glassy conditions and slow sets around 2ft, ahead of freshening northerlies, whilst Sunday had a more patchy coverage of surf as northerly winds freshened in some spots (but not others) ahead of a S’ly change. Today we’ve seen the same small E’ly swell persist with light to moderate S’ly winds, and a long period S’ly swell is now pushing up along the Mid North Coast and into the Far Northern NSW coast. See the spectral data below from the Tweed buoy, which shows faint long period forerunners in the 22-23+ second range.

This week (Dec 24 - 27)

For calibration, we’ve already had reports today of 8ft sets across Southern NSW as this long period southerly swell starts to reach a size maximum. With peak swell periods around 21 seconds at one of the Sydney buoys, this swell is so far performing as per expectations. 

As such, there’s really no need for me to alter Friday’s projections. Which is: a peak later today (Mid North Coast) and/or tomorrow (everywhere else), with a much greater size range between exposed/protected coasts than under normal south swells.

South facing beaches south of Byron should pick up 5-6ft sets, and a handful of offshore bombies and south swell magnets could deliver bigger bombs. But, any beach not exposed to the south will be much, much smaller - this is a less reliable southerly swell than normal, so your local beach may not respond in the normal way due to the unusually large swell periods. Often, the more flukier the southerly swell source, the less reliable the energy is of reaching maximum size north from Yamba through to Byron (Coffs tends to be one of the most consistent south swell magnets in the region). 

As for SE Qld, I am still not expecting much size (relatively speaking) across most outer points and open beaches. Most Gold Coast spots will probably see 1-2ft sets though south facing beaches and exposed northern ends should manage 3ft+ sets. Expect a little less size across the Sunshine Coast. 

As for conditions, a small Tasman high will steer winds around to the NE - they won’t be terribly strong and most locations should see a window of light variable conditions early, but it will crop up during the day. 

In fact, just on winds for the rest of the week - we’ll see a synoptic easterly flow every day though it won’t be too strong in the mornings, and should tend E/SE across SE Qld, but more E/NE across the Mid North Coast. This will be the product of the Tasman high, firming a ridge across the lower Coral Sea, and will also contribute some small trade swell for SE Qld from Thursday afternoon into Friday - no major size but a few average quality 2ft+ sets at exposed beaches.


We’ll also see a continuation of small underlying E’ly swell all week from a distant trade flow out NE of New Zealand. Again, no major size is expected but it’ll stop exposed beaches from becoming flat.
 
Back to Northern NSW, and Tuesday’s south swells will begin easing into the afternoon and continue a downwards trend through Wednesday. South facing beaches south of Byron may still be slightly overpowered with inconsistent 3-5ft sets, but it’ll be much smaller elsewhere. By Thursday morning this south swell will be half the size again, and a distant memory from Tuesday’s strong energy.

Friday will see small residual swells from the east and south. Aim for an early surf before the breeze picks up. 

This weekend (Dec 28  - 29)

Nothing major is expected this weekend, with just a continuation of small E’ly trade swell from the ridge through the lower Coral Sea. It’s expected to strengthen, but also rotate a fraction outside the optimal swell window so this should keep size around the 2-3ft mark across SE Qld and Far Northern NSW beaches, with smaller surf south from Ballina.

Elsewhere, a series of very poorly aligned fronts through the Southern Ocean later this week will generate minor S’ly swell for exposed south facing beaches in Northern NSW though I don’t think we’ll see much size. 

Local winds look to be influenced by the Tasman high; that is, mainly out of the eastern quadrant all weekend (E/SE in SE Qld and E/NE across the Mid North Coast). A small trough may push up the South Coast into Sunday, disrupting the onshore flow in SE Qld but freshening northerlies across the Mid North Coast. I’ll have a better idea that in Wednesday’s update. 

Next week (Dec 30 onwards)

As mentioned in Friday’s notes, a Tropical Cyclone is expected to form north of Fiji around Xmas Day or Boxing Day. Current expectations have it tracking south, finally entering our swell window this Friday or Saturday.

The latest model projections have this as a large, slow moving system between New Zealand and Fiji for a few days - which is very exciting - though with a slow E’ly track (see below). Normally this would have an adverse effect on surf potential, however at this stage it shouldn’t be too detrimental, given its duration within our swell window.

As such, I'm expecting several stages of cyclone swell to arrive from around Monday 30th.

Initially, we’re looking at E/NE energy ahead of a stronger E’ly swell that’ll arrive through the middle of the week - so all up, we’re looking at a three or four day swell event, maybe a little longer. However, there’s not a lot of confidence in how much size we’ll see - it does indeed look like being a big, beefy system - but the strongest winds are modelled to be on its western flank, aimed towards Vanuatu.

We will see the model guidance swing around over the coming days (at the moment, our surf model is only estimating 4ft surf for the Gold Coast on New Years Day), and I’m reasonably confident that we’re looking at some excellent, solid waves in and around the turn of the New Year. Let’s ballpark peak size for this event around the 6ft mark for now, and revise the outlook over the coming days.

See you Wednesday!