South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Monday 6th April)

Best Days: Tues/Wed/Thurs: small waves at outer points under S/SE airstream. Fri: plenty of E'ly swell and easing S'ly swell, with lighter winds. Sat/Sun: light winds, easing E'ly swell and a pulse of S'ly swell - possibly strong - for Northern NSW (Sun). 

Recap: E’ly swells provided good waves to exposed beaches over the weekend. Size came in around 3ft at most open stretches though there were a few scattered reports of 4ft sets, mainly on Saturday. Today eased back to 2-3ft. Conditions were northerly-wind affected on Saturday, a few locations saw pockets of lighter NW winds but Sunday offered the best conditions with light offshore winds ahead of developing southerly winds. Today has seen early light SW winds in most areas swing fresh S’ly through SE. 

Snapper Rocks showing form this afternoon

This week (Apr 7 - 10)

A strengthening ridge across the coast will maintain moderate to fresh S/SE winds from Tuesday thru’ Thursday. A few regions might be lucky and pick up brief windows of lighter S/SW winds, but they’ll be the exception rather than the rule. 

As for surf, we’ve got a couple of source on the cards but nothing overly special.

A supporting ridge below TC Harold - current devastating the Vanuatu region - will supply small, intermittent E’ly swells all week. Inconsistent sets in the 2-3ft range are likely all week. 

The developing coastal ridge will stretch from the Mid North Coast into the Coral Sea, and although poorly aligned for our region (way too meridional - north/south - in orientation), we will see a small mid range swell, mainly at south facing beaches south of Byron with 2-3ft sets, smaller elsewhere. 

The supporting high pressure system to the south-west will broaden through the Tasman Sea later this week and we’re looking at a swing in the swell direction to the E/SE by late Thursday and Friday, mainly favouring SE Qld with 3ft+ sets by Friday, though it’ll be smaller running down the points. Local winds should have relaxed a little by this stage too, though it’ll still be out of the SE quadrant north of the border. 

The main swell even on the charts for this week is a southerly groundswell, thanks to a strong long wave trough tracking across Tasman Sea longitudes. 

Initially, the early energy will be generated by weaker and/or less favourably aligned winds exiting eastern Bass Strait, and also along the Southern NSW coast. However the parent low - positioned well to the south of Tasmania this morning - is showing a decent fetch of 40-45kts winds, and will today track north-east through our south swell window, generating a larger pulse that’ll provide the biggest waves of the week.

Tuesday will generally see small southerly swells across Northern NSW, and the strong pulse from the parent low will push across the Northern NSW on Wednesday, reaching 3-5ft at south facing beaches south of Byron. Unfortunately, they’ll be quite wind affected and everywhere else will be a lot smaller. I’m not expecting much of this energy to penetrate north of the border. Wave heights will then ease steadily from Thursday.

Looking elsewhere, and TC Harold won’t directly generate any swell for us. It’s currently inside the New Caledonian swell shadow, and once it clears this region it’ll accelerate to the east towards the South Pacific, too fast to generate swell for the Australian East Coast. 

Over the last week or so I’ve been mentioning a deep trough/tropical low well to the east, inside the NZ swell shadow that had some peripheral potential. Over the last few days the models have ever so slightly shunted this system to the south, to the point where I can be a little more confident in ruling out swell prospects for Southern NSW, but we should still see a small spread across Northern NSW - probably below that of the existing swells - whilst SE Qld should pick up inconsistent 3ft sets on Thursday and Friday.

This weekend (Apr 11 - 12)

Light winds are expected over the weekend as a high pressure ridge moves in from the west. This should create clean conditions across all coasts, both days. 

As for surf, this week’s easterly and southerly swell sources will slowly abate. Saturday morning should still maintain 3ft sets across SE Qld, before size falls slowly into Sunday. Expect a little less size from this source as you head south of the border. 

However, there is some southerly swell potential on the way for Northern NSW. At this stage there’s still a bit of divergence between the models so the specifics aren’t yet clear, but another amplifying node of the Long Wave Trough is expected below Tasmania later this week, and we’re looking at a long period S’ly swell arriving around Sunday that cold throw up some solid sets at south facing beaches south of Byron. 

This output (via GFS, see below) shows incredibly strong winds aimed away from our swell window, but the resulting spread of energy would still kick up a large swell event somewhere in the 4-6ft range at reliable south swell magnets - however the flukey swell source would result in a wide range in size across the region. And I’m not expecting much of this swell to reach SE Qld, away from a handful of south swells magnets that might pick up 3ft sets. 

Current indications are for good winds too, offshore though perhaps fresh at times.

This is all still quite some time away - and let me reiterate that the models are not completely on board with this scenario right now - so let’s take a closer look on Wednesday, as they’ll start to consolidate towards a common position by then.

Next week (Apr 13 onwards)

Powerful secondary fronts trailing behind the system responsible for the weekend’s south swell should maintain strong southerly swells across Northern NSW through the first half of next week, though the poor fetch alignment will keep a lid on anything overly sizeable.

That’s the main focus of the long term charts. We’ll firm up things in more details on Wednesday. 

See you then!