South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Monday 12th March)

Best Days: Great waves pretty much every day across protected points; smallest early Tues with the lightest winds of the period. Quite sizeable around Thurs with a combo of swells related to a (likely) Tropical Cyclone in the Coral Sea.

Recap: Steady SE trade swells held out through the weekend, around 4-5ft across exposed Far Northern NSW coasts, with slightly smaller surf south along the Mid North Coast, and also up in SE Qld (with the best waves found at semi-protected outer points). Winds remained moderate to fresh SE across northern regions, with isolated pockets of early S’ly winds. We saw much more favourable conditions across the Mid North Coast. Wave heights eased more noticeably today and local winds have also eased, allowing for cleaner surf though still best suited to the outer points. 

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This week (Mar 13 - 16)

I though we’d seen a few complex synoptic charts over the last month or so, but the current outlook takes the cake.

So, starting off with today’s energy and it’s predominantly easing swell from the weekend that’ll bottom out into Tuesday.

Ex-TC Hola strengthened a ridge off New Zealand’s North Island on Saturday, developing a broad E/SE fetch that was aimed nicely into the Northern NSW and SE Qld coasts. We’ll see a couple of phases of energy from this system, building strongly through Tuesday and holding into Wednesday morning, though the biggest surf (4-6ft) will be found across exposed beaches in Far Northern NSW due to its perpendicular alignment to to the swell direction. It’ll be equally strong but slightly smaller across the Mid North Coast, owing to a sightly less favourable fetch alignment. 

SE Qld will also see a healthy percentage of size from this swell, but the biggest waves across these coasts will be at exposed headlands and far northern ends, with marginally smaller surf across the outer points (3-5ft), and much smaller surf across the inner points.

Note: wave heights may be marginally undersized at dawn on Tuesday and will be biggest through the afternoon.

Tuesday will deliver the lightest winds of the week, variable through the morning across mosts coasts though lingering S’ly breezes are likely at some exposed regions. We’ll then see freshening SE winds throughout the afternoon, though no major strength is expected until Wednesday.

And here where things get really interesting. Not only will we have a mature E’ly groundswell from ex-TC Hola in the water for the middle of the week, we’ll also have an approaching Tropical Low (and very likely, Tropical Cyclone) in the Coral that’s going to strengthen SE winds about the SE Qld and Far Northern NSW region, delivering strong new swell from a couple of directions.

Now, I’ve been discussing this system since last Monday and the models have been pretty good so far at long range. However, we’re getting close to the early stages of cycloegensis which means the models are starting to reach a consensus, which also means we can start to firm up the prediction. And it’s quite a complex outlook. 

Initially, we’ll see building NE swell (on top of the pre-existing E’ly swell) in SE Qld through Wednesday afternoon, with size from this source reaching between 3 and 5ft on dusk (remember: this'll favour locations that are usually sheltered from swells originating from the east thru' south). This energy will be generated by a developing NE fetch on the eastern flank of the cyclone, which is expected to track SW towards the SE Qld region through Tuesday - a favourable direction, along with favourable ridging allowing for an unusually broad fetch to develop in this swell window. 

The cyclone will concurrently broaden and lengthen a strong SE fetch through the western Coral Sea (tending more E’ly south of the cyclone), and this will contribute a similar sized E’ly swell throughout Wednesday, reaching the Sunshine Coast first, then extending southwards into Thursday. 

The cyclone itself is expected to track reasonably close to the mainland - within 400-500km of Byron Bay on Thursday morning - and we’ll see a confluence of peaking swells across the region through Thursday morning, with fresh to strong S’ly winds from Yamba to the Sunny Coast. 

In my opinion, surf model guidance is not bad for this event, but may be slightly overestimating the surf size for this event because it’s combining all of the swell energy into a singular train (plus a minor south swell) - of which there’s also likely to be quite a lot of windswell contamination in the mix too. So, I don’t think we’ll see 4.1m @ 10.7 seconds out of the east; we’re more likely to see a broad mix of disjointed swells from several parts of the eastern quadrant. 

Still, it should push into the 6-8ft range at times at exposed beaches (smaller across protected points), and with gusty S’ly winds there won’t be many options available away from sheltered spots. Expect slight smaller surf across the Mid North Coast from all swell sources, due to the slightly larger travel distance and less favourable alignment. 

It’s also worth pointing out that when tropical systems such as this skirt the coast we often see periods of SW winds, which may open up opportunities across some reefs and less sheltered points. I’ll fine tune these thoughts on Wednesday. 

Looking beyond Thursday and wave heights will ease rapidly into Friday with winds remaining fresh out of the southern quadrant. As the cyclone moves away form the coast we’ll see a greater chance for early periods of SW winds but there’ll still be a lot of wobble at exposed spots. Far Northern NSW should continue to pull in 4-6ft waves early morning, with slightly smaller surf in SE Qld and across the outer points (smaller again across inner points, especially as the NE swell recedes more rapidly than the others). The Mid North Coast will also continue to see smaller surf than its northern counterpart.

This weekend (May 17 - 18)

Model guidance is maintaining the leftovers of this cyclone well off the Far North Coast into weekend, possibly extending a new ridge into the coast. If this eventuates we’ll see a continuation of decent mid-range E/SE swell all weekend, though with redeveloping SE winds across SE Qld and Far Northern NSW.

Early ballpark figures are in the 4-5ft+ range at exposed beaches in the Far North tapering off the 3-4ft+ across SE Qld and smaller again across the Mid North Coast. 

At the same time, we also have a strong, long period S’ly groundswell that’ll move through the Northern NSW region, generated by a deep low south of Tasmania later this week. South swell magnets south of Byron should pick up 4-6ft sets from this source, however surf size will be smaller at beaches with less southerly exposure. Size will ease slowly through Sunday. 

Compared to regular south swells, this event will be slightly more S/SW of S, meaning more acute in direction, and thus favouring a smaller percentage of locations for maximum size (though, the long periods will help to boost surf size considerably at offshore bombies, where we could see some larger waves. 

Don’t expect a lot of this source swell to make its was into SE Qld, other than at exposed northern ends and south swell magnets. As it is, the pre-existing E/SE swell will probably be the dominant source anyway. 

Conditions look good south of Yamba with mainly light winds tending N’ly. 

Next week (May 19 onwards)

We’ve got lots of activity in the pipeline for next week, with model guidance suggesting a new E’ly dip in the northern Tasman Sea (bringing a mid-week E’ly swell), plus a strong frontal passage across Tasmanian longitudes, generating plenty of strong south swell.

Bring it on! See you Wednesday.