South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Wednesday 16th August)

Best Days: Thurs: early N'ly windswell, biggest across exposed N facing beaches on the Gold and Tweed Coasts. Much smaller elsewhere, and easing during the day. Fri: keep an eye out for a late increase in S'ly swell across Northern NSW (low chance SE Qld). Sat/Sun/Mon: very large S'ly swell, best on the SE Qld outer points on Sunday morning. Smaller Sat AM and then from Sun PM thru' Mon.

Recap: Tuesday’s leftover S/SE swell was a little bigger than expected early morning around 2-3ft south of Byron, but it eased steadily throughout the day and was pretty much gone this morning. Today has seen strengthening northerly winds and building N’ly windswells, now around the 3ft+ mark at a handful of exposed locations (though very low in quality). 

Late sets of northerly windswell at D'Bah

This week (August 17th - 18th)

We’ve got a big weekend of south swell ahead, but prior to then the outlook is pretty tricky. 

The fetch generating today’s N’ly windswell is expected to reach maximum strength in the early hours of this evening, but then veer NW overnight and slowly ease in strength through the early hours of Friday morning.

Due to the close proximity of the fetch to the coast, we’ll see a quick translation in size at the coast as the wind relaxes. And I am concerned that we may see quite a lot of size lost before sunrise. As such, the dawn patrol will be your best chance to make the most of this unusual local N’ly windswell. This is not a high confidence swell event due to it being a weak windswell with an expected overnight peak. 

Exposed north facing beaches along the Gold and Tweed Coasts should see early 2-3ft sets, with smaller surf elsewhere (poor alignment for the NSW coast south of Byron, and a short fetch length for the Sunny Coast). There should however be some small rideable waves here. Expect an easing trend throughout the morning with small surf expected everywhere for the afternoon.

A weak shallow S’ly change overnight across Northern NSW will clear by dawn and should give way to mainly light variable winds south from Byron. The Sunshine Coast, and to a lesser degree the Gold Coast, will see moderate NW winds all day and therefore clean beachies. Let’s hope the morning delivers a few winding left-handers.

A small S’ly swell may glance the Mid North Coast into Thursday, originating from westerly gales exiting eastern Bass Strait this afternoon. They’re modelled to have a very slight S’ly component, and due to the strength and width of the fetch, may be just enough to favour a minor spread of south swell into a handful of reliable south swell magnets throughout the afternoon. I’m not holding my breath though.

Friday is a very complex affair.

Freshening N'ly winds are possible overnight Thursday, north from Moreton Island, and may provide some small N'ly wind waves across the Sunny Coast into Friday morning (but unlikely the Gold Coast or anywere south of the border). Don't get your hopes up.

A vigorous front crossing the coast early Friday will extend a broad fetch of W/SW gales off the Southern NSW coast. This will generate heavy W/SW swells for the South Pacific islands, but we should also see an (unusual) spread of swell back into the Australian mainland. At the coast it’ll feel southerly in direction, despite its westerly origin. 

As mentioned in Monday’s notes, it’s worth pointing out that unlike directional south swells - which track somewhat linearly up the coast - this event is expected to ‘spread’ back into the mainland, and thus may arrive much more simultaneously across the region than what we’re used to seeing. 

However, confidence is not high on the size estimations. Our model is estimating an increase to 4ft at south facing beaches in Coffs by late Friday, but the primary swell direction is W/SW tending SW - so I think it’s not coping well with the sheer strength of this frontal passage. Saturday is a safer bet that we’ll see some strong surf out of the south. 

Anyway, I have to stick my neck out, so I’m going to call tiny surf in Northern NSW early Friday morning, ahead of a mid-late afternoon building trend at south facing beaches south of Byron with sets around 3-4ft+ right on dark. The Gold Coast will probably remain tiny for much of the day across the points, but exposed northern ends could see a few late 2ft sets. I doubt we’ll see anything of substance on the Sunny Coast from the south on Friday as it's even less favourably aligned for these events. 

As for conditions, expect fresh and gusty W/SW winds. 

This weekend (August 19th - 20th)

So, the aforementioned swell spread from the W/SW fetch should peak overnight and then ease throughout Saturday - only to be replaced by a bigger, stronger and more direct southerly groundswell, generated by a deep cut-off low that’s currently displaying 50kt S’ly winds, SW of Tasmania aimed into the Torquay coast.

Early Saturday morning should see 4-5ft sets at south facing beaches south of Byron, and small waves across SE Qld, biggest at exposed northern ends (2ft+, smaller across the outer points).

Over the coming two days, the cut-off low in the Southern Ocean is expected to track north-east underneath Tasmania, then north-northeast into the lower Tasman Sea. It’ll be working on the active sea state generated by earlier fronts, and its track is very good for a possible captured fetch scenario, which boosts wave height potential above that of an ordinary synoptic event.

At the same time, the associated front will push up and along the Northern NSW coast, strengthening winds from the S/SW. So only sheltered locations will offer anything worthwhile this weekend.

As for size - we’re looking at a building trend throughout Saturday ahead of a peak early Sunday. The latest model guidance has increased the size potential from this progression (though is overcalling the Northern NSW wave heights IMO, up to 10-12ft on Sunday morning). We’re probably looking at solid, wind affected 8ft+ surf at south facing beaches south of Byron at the height of the swell (smaller early Saturday, and late Sunday), with most open beaches picking up 4-6ft surf, and smaller waves again inside sheltered southern corners. 

The upgrading of this system has also improved the surf potential for SE Qld and with the associated winds, this will be the pick of the region. The outer points may struggle through Saturday due to the southerly swell direction, but should reach 2-3ft by late afternoon. Sunday looks like the best option with early SW winds and 3-4ft sets across the outer points, and bigger waves at exposed northern ends (though only small surf across inner points due to the strong southerly component in the swell direction).

Let’s take a closer look on Friday - but for now the weekend’s shaping up very nicely for SE Qld surfers. 

Next week (August 21st onwards)

Sunday’s large S’ly swell will ease slowly through Monday though we’re still looking at plenty of size across south facing beaches; still 5-6ft south of Byron (smaller elsewhere) and 2-3ft across the outer points in SE Qld. Expect smaller surf into the afternoon. 

Winds will veer NW and maybe N’ly during the day as a weak front approaches for the SW, so aim for an early surf. 

The next frontal system will enter the lower Tasman Sea early Tuesday and provide a small, brief flush of S’ly swell for Northern NSW on Wednesday but no major size is expected. 

A strong series of fronts and lows will then traverse the waters south of Tasmania on Wednesday and Thursday, setting up a fresh S’ly swell for Northern NSW on Friday, Saturday and Sunday. More on this in Friday’s update.