South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Monday 27th March)

Best Days: Chance for more peaky N'ly swell at NE swell magnets in SE Qld on Tuesday and Wednesday. Tricky winds Wed/Thurs and a low off the coast Fri, so a chance for points Fri/Sat/Sun. Northern NSW may see a small window of fun NE swell on Thurs ahead of a gusty S'ly change. 

Recap: The weekend delivered plenty of quality S/SE swell across Northern NSW, originating from a Tasman Low. Unfortunately, surf size remained very small in SE Qld due to the swell direction however the Tweed Coast picked up 3ft sets and south facing beaches south of Byron were closer to 4ft. Size eased a little into Sunday afternoon and further into this morning. Today we’ve seen a rare NE groundswell push across exposed north facing stretches of the SE Qld region. This swell originated from the early stages of TC Debbie (before it was classified at cyclone strength), and some beaches are seeing 3-4ft sets - perfectly inline with model expectations (though it needs to be pointed out that the models only came inline for this swell to reach south of Fraser Island over the last few days). Without enough time to properly hindcast this swell right now, a quick analysis suggests that the fetch around the low was right on the periphery of SE Qld’s acute northerly swell window - the regional swell direction here is actually very north, though nearshore refractive processes swing this around to the NE or even E/NE. The fetch was initially located some 1,000km north of the SE Qld region so it’s impressive as to how much size has made it ashore so far south. However, it is also interesting to note that not all exposed locations are picking up a lot of size - The Pass at Byron Bay is seemingly well positioned for this swell direction, and is Australia’s most easterly point - but it’s less than half the size of Snapper. There’s also a large difference in buoy data across small coastal stretches - for example the Gold Coast and Tweed buoys - the former is half the size of the latter, and swell periods are markedly different. This is also reflected in surf size, with Burleigh significantly smaller than Snapper.

Lovely lines at Snapper

Much smaller at The Pass

Currumbin looking tidy

Even Noosa had some fun peelers

This week (Mar 28th - 31st)

Note: Forecaster Notes will be brief this week as Craig’s on leave.

OK before we get started, it’s worth noting that our southern swell window will remain inactive until late in the week. So aside from a small, moderate ENE fetch developing just to the NE of SE Qld (which should supply some small peaky short range swell from Wednesday through Friday), we can look at Tuesday and early Wednesday in relative isolation, with regards to swell energy from TC Debbie.

This also means that (because of the N’ly swell favouring SE Qld, but very few places in Northern NSW) we can quickly sum up the surf potential south of Byron for the next few days: mainly small. 

So back to TC Debbie. In Friday’s notes it was deemed that the (then) developing tropical low was just outside of SE Qld’s swell window, and that only a small N’ly fetch on its north-eastern flank was likely to generate any swell for the region. 

As it turned out, TC Debbie developed a little more slowly than initially thought, tracking very slowly to the mainland but at the same time, broadening the width of the fetch as it strengthened. Although right on the periphery of the swell window, this has resulted in a much bigger swell than initially expected. 

Therefore it would be risky to dismiss TC Debbie’s further developments over the weekend. Because although its not located closer to the coast, the northerly fetch (actually more N/NW) has broadened further. This is expected to generate another pulse of swell for Wednesday, though I fear this time around its direction will be a little too much west of north, meaning it’ll mainly bypass the coast enroute to New Zealand.

So, the big question is: do we trust the model guidance? It did very well for the Gold Coast today but I’m not especially confident in N’ly cyclone swells because they’re extremely rare events - so it’s hard to draw on previous experience. 

The safest bet is to assume today’s model performance will be repeated, but I’m going to downgrade expectations - our model has up to 3ft through Tuesday and Wednesday but I think it’ll be closer to 2ft+ at reliable NE swell magnets north of Byron, and smaller elsewhere - such as the northern Gold Coast and many parts of the Sunshine Coast.

The models are also suggesting 3ft of N’ly swell will make its way into NE facing beaches across Northern NSW over the coming days too. I just can’t quite see how this swell will wrap efficiently into Northern NSW, given the shadowing effect of Fraser Island, Moreton Island, Point Danger and Cape Byron. As such I’m not expecting much from this source over the coming days, south of Byron - though I absolutely can’t rule out a handful of sneaky north swell magnets raking in occasional sets.

TC Debbie is expected to take a southward track overland mid-week and in doing so will freshen E/NE tending NE and then NNE winds across the region. They’re likely to become quite gusty across SE Qld through Thursday.

The models are also now converging on a solution whereby we see the remnants of TC Debbie merge with a gusty southerly change pushing up from the south on Thursday, forming a new low pressure centre off the SE Qld coast on Friday. This is expected to drive strong to gale force S/SE winds across the region, though the surf potential will depend on where the low is located. At this stage it looks like we’ll at least see some solid windy waves across the protected points north of the border to finish the working week though I’ll hone in on the specifics on Wednesday.

Elsewhere, Thursday has some potential across Northern NSW with a building combo of N/NE swell from the Coral Sea developments, and a period of light variable winds ahead of a gusty southerly change

Friday will be windy and close to a write off across Northern NSW due to the strong southerly winds, though there’ll be plenty of swell and therefore protected southern corners and points could have a few options. 

This weekend (Apr 1 - 2)

With the models changing dramatically from run to run, it’s hard to have much confidence in the weekend’s outlook. But by and large it’s looking to be large, wet and windy as this low maintains position off the coast. Right now let’s pencil in a couple of reasonable days of waves across the points. I’ll revise in more details on Wednesday as the models should be starting to settle down by then.

We’ll also see some long period S’ly swell (19-20+ second) - originating from a sneaky  polar off the Ice Shelf south of SA on Wed and Thurs - push up the Northern NSW coast later Sunday, peaking through Monday. Though it may not be discernible beneath the local noise.

Next week (Apr 3 onwards)

Very tricky long range outlook due to the complex trough/low situation in the southwestern Coral Sea - but it’s certainly looking to be quite active. Plus we’ll also see some lingering long period S’ly swell on Monday from the sneaky polar low south of SA this week. But only at reliable south swell magnets in Northern NSW.