South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Friday 17th January)

Best Days: No great days due to poor winds. Which is a shame, as there are plenty of waves on tap throughout the forecast period, including some impressive long period E/SE groundswell later next week across SE Qld

Recap: E’ly trade swell has maintained 2-3ft+ surf across most SE Qld and Far northern NSW beaches, with slightly smaller surf south of Yamba. A small long period S’ly swell added occasional 2-3ft sets into the mix across Northern NSW today. Winds have been mainly NE, creating bumpy conditions at many coasts, though there have been pockets of light variable conditions scattered here and there. Nice to see some rain too!

This weekend (Jan 18 - 19)

There’s no major changes to be made to the weekend outlook. 

NE winds will remain entrenched across the coast, as a stationary high in the eastern Tasman Sea interacts with a broadening trough of low pressure across the south-western Tasman Sea. 

There are a couple of possible exceptions to this scenario though. The trough off Southern NSW will influence the northern Hunter region and this may extend northwards into the lower Mid North Coast on Saturday.

Additionally, some high res models is intensifying a small surface trough north-east of Brisbane on Saturday, which may enhance the NE thru’ E’ly wind field across the Gold Coast and Northern Rivers, but may also lead to a period of variable winds across the Sunshine Coast. 

But, these are all outliers within an otherwise prolonged period of broadly unfavourable synoptic winds. 

As for surf, we’ll see a continuation of trade swells all weekend in and around the 2-3ft range, building a little into Sunday afternoon thanks to a secondary trade swell source developing north of New Zealand today. This should reach 3-4ft across most coasts. Additionally, the enhanced NE thru’ E’ly flow adjacent the northern region on Saturday has the potential to add another foot or two of local windswell into the mix. 

Also in the mix over the weekend will be a fresh southerly swell, originating from the present trough off Southern NSW, of which its southern extent will reach as far south as about 55S during the weekend (about mid-way between Tasmania and Antarctica) however wind strengths will be only modest. The resulting surf size will max out at about 2-3ft+ across Northern NSW’s south facing beaches (south of Byron), peaking Sunday.

Next week (Jan 20 onwards)

The latest model guidance has swung next week’s persistent NE airstream around to more of a straight N’ly direction, at least across SE Qld and Far Northern NSW.

We’ll see N/NE winds across the Mid North Coast, and persistent troughiness across Southern NSW next week may continue to periodically influence this region with patches of light varibale winds (later Tues/Wed looking OK at this stage, and then again around Fri).

As for surf, there won’t be any shortage of energy in the water. 

The weekend’s south swell will be mostly gone by Monday, but we’ll see plenty of easterly quadrant swell from the South Pacific, sourced from a strengthening trade flow in response to TC Tino moving south from the tropics.  

Unfortunately, I am still not expecting TC Tino to align favourably within our swell window at first. 

It’s a large system and will probably reach Cat 2 status over the coming days, but it'll travel perpendicularly through our swell window, and a strong ridge of high pressure to the east will ensure its eastern flank has the strongest winds, and they’ll be aimed towards New Zealand. The other strong flank (western) will be aimed towards Vanuatu.

We’ll still pick up some useful E’ly swell from the supporting ridge to the south (so not cyclone swell, per se), but most open beaches will probably max out at an inconsistent 3-4ft, maybe 3-5ft. But with the accompanying N’ly thru’ NE winds, options will be limited. 

However, TC Tino will undergo extratropical transition east of New Zealand early next week and broaden into an incredible sub-tropical low (see below). Whilst it’ll mainly be located in the NZ swell shadow at this time, we’ll see a reasonable spread of E/SE groundswell diffract around the North Island.

This swell will only favour the extreme northern end of the East Coast (south of the Barrier Reef), and the models are still not really liking this system - but with 50-60kt at the core of the sub-tropical low, we’ll be looking at peak swell periods of around 16-17 seconds arriving Thursday, with swell energy peaking Friday. So, I think it's worth monitoring closely for surf potential.

As for how much size - well, as I mentioned on Wednesday, had this system been positioned ten degrees further north, with a better alignment through our swell window (i.e. more E'ly than SE), there wouldn’t be much change out of 10-15ft across some locations. But, the poor location/angle and considerable travel distance will shave off a lot of size. Furthermore, wave heights will decrease with increasing southerly latitude.

So, we’ll need to fine tune things on Monday but for now let’s peg size peaking around 4-5ft+ across parts of the Sunshine Coast, then 3-5ft from the Gold Coast down to about Ballina, and then 3ft+ south to the Lower Mid North Coast. Also, set waves will be extremely inconsistent owing to the large distance between the swell source and the mainland.

But will it matter if there’s a fresh northerly breeze accompanying this swell event? That’s the current indication from the model guidance.

So, keep your expectation low, and we'll have a much better idea on Monday.

Have a great weekend!

Current JTWC track for TC Tino