South East Queensland and Northern New South Wales Surf Forecast by Ben Matson (issued Friday 10th July)

Best Days: Sat: small clean swell at Northern NSW swell magnets, early morning. Tues/Wed: strong pulsey south swell at south swell magnets in Northern NSW. Much smaller elsewhere. Thurs/Fri: more moderate, clean south swell but only for Northern NSW's south swell magnets.

Recap: We’ve seen some fun waves across Northern NSW beaches these last few days thanks to a persistent, albeit inconsistent S’ly swell in the 3ft+ range at exposed spots. A small SE swell built across SE Qld early Thursday but eased a little overnight, holding small through today. Winds have been generally favourable though SE Qld see a lingering S/SE flow through Thursday.

This weekend (July 11 - 12)

Saturday morning will be the pick of the weekend, and only Northern NSW will see any value. The sustained southerly swell that’s occupied the region for the week is fading in size and won't last for much longer.

In Northern NSW, exposed beaches may see a few stray, infrequent 2ft sets through the morning, but it’ll be smaller elsewhere and wave heights will trend downwards throughout the day. 

Across SE Qld, there’ll be hardy any leftover SE swell on Saturday (just 1ft+ on the Sunny Coast, smaller on the Gold Coast), and the region’s handful of south swell magnets probably won’t see much of the leftover southerly swell in the morning either. Elsewhere it’ll be tiny. However, winds will freshen from the NW everywhere so the open beaches will be clean.

As for Sunday - it’ll be tiny to flat at most locations, with fresh and gusty W’ly winds across all regions.

Next week (July 13 onwards)

We’ve got a very complex period ahead, and to be honest I’m still not especially confident on the surf outlook for early next week. 

As we’ve been discussing for some time, a significant low pressure system is expected to form off the Far South NSW Coast on Sunday. At this stage it still looks like being a Tasman Low, and not an East Coast Low, due to several characteristics (low rainfall progs, and the low’s modelled eastward track) however these are somewhat moot points compared to the surf outlook.

In Wednesday’s notes I detailed some concerns that approaching polar fronts would become absorbed into the Tasman Low, maintaining a strong westerly component across the broader airflow around the system. This suggestion has firmed up in recent model runs, and is now even affecting Monday’s potential (as well as our mid-week possibilities). 

As per the animated image to the right (eight 6-hourly time steps from Sunday evening to Tuesday morning, courtesy of the GFS model), you can see that initially the developing low remains too close to the mainland. As such the southerly gales strengthening around the western flank of the low are at first, still positioned inside Bass Strait. 

In this model run, we eventually see a thin fetch of SW gales across the coast - this is during Monday - ahead of a broader W/SW thru’ SW fetch extending east of Bass Strait overnight into Tuesday. However, for the most part the fetch is aimed well and truly away from the coast, which means we’ll only see sideband energy across the NSW coast.

Now, the sheer strength of the system and its close proximity to the mainland will somewhat override the directional deficiencies, ensuring we see a reasonably solid south swell. However it’ll probably be about half the size (or less) than that of a well aligned south or south-easterly fetch. 

One other point that needs to be said: the other atmospheric models are not quite in agreeance with the finer points of this (yet to develop) system, so due to the complex nature and its close proximity, some elasticity in the timing and numbers would be greatly appreciated.

So, on to the specifics - Monday will remain near flat across all regions with gusty W’ly winds.

As the SW fetch drops off the southern NSW coast during the day, we’ll see a refracted SW swell (S’ly at the coast) push up across Northern NSW, to arrive overnight and provide waves into Tuesday. The acute swell direction will cause an enormous range in wave heights across the coast, however the good news is that conditions are expected to be pretty good thanks to a rapidly weakening pressure gradient as the Tasman Low consolidates in the southern Tasman Sea, resulting in light winds.

Then, with the Tasman Low remaining slow moving through the Tasman Sea for a few days we’ll then see a pulsey series of refracted southerly swells through the middle of the week and beyond. 

How big? South facing beaches across Northern NSW could see anywhere between 4ft and occasionally 6ft through Tuesday and possisbly early Wednesday, but most open beaches are probably looking at clean waves in the 2-3ft range, and it’ll be tiny inside southern corners. As a reference point, this particular event is expected to be more greatly exaggerated than this week's south swell, which had a broader spread and was more S'ly than SW in direction. And due to the swell source being of sideband origin, it'll also be quite inconsistent at times. 

It's also quite likely that - apart from the region's handful of south swell magnets - SE Qld will dip out in the swell department from this series of south swells. Expect mainly tiny conditions across the Gold and Sunshine Coasts all week, as the eastern swell window also looks to remain inactive.

As for the second half of the week in Northern NSW, it’s hard to have confidence but right now it seems that the low will remain in our southern swell window through Wednesday and Thursday, which suggests some form of reasonably strong (if only moderately sized) south swell up until Friday or Saturday, probably somewhere between 3ft and possibly 5ft at south swell magnets if we're lucky. Again, expect smaller waves at most open beaches due to the swell direction - although probably not quite as extreme variation as we're expecting Tues/Wed.

And one final other possible swell source - N/NE gales in the central Tasman Sea from Sunday thru’ Tuesday are rather poorly aligned for the coast, and they also track unfavourably to the east - but they still can’t be ruled out as a possible source of small NE swell, but probably just for Southern NSW Coast though (I doubt we'll see anything across Northern NSW). However I’ll evaluate this more closely in Monday’s notes. 

So there ya go - after a great week of steady south swell, it looks like we’ve got another week ahead with more of the same. See you Monday.