South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Friday 21st July)

Best Days: Sat/Sun: large clean SE groundswell building across Northern NSW, with light offshores. Plenty of fun waves in SE Qld too. Mon/Tues: smaller residual swells with good winds. Wed: new S'ly swell for Northern NSW with W'lies. 

Recap: We’ve had a couple of overlapping south swells over the last two days, with wave heights generally coming in within ballpark expectations - 4-5ft south facing beaches south of Byron on Thursday, building to 5-6ft today. Across SE Qld, surf size has been much smaller - around 2-3ft at exposed northern ends of the Gold Coast and tiny on the points on Thursday, and hardly anything on the Sunshine Coast. Today looks a little bigger across both coasts, though only just. Winds were W’ly on Thursday so it’s been clean in general though we’re seeing a SW tendency today that may veer S/SW at some point.

This weekend (July 22nd - 23rd)

We’ve got some large, powerful waves on the way for the weekend. The only concern I have is with the timing of the initial swell front on Saturday.

Today’s short and mid-range south swells will ease through Saturday morning, so we’ll see a period “between swells” early in the day where it’ll be very small inconsistent across SE Qld away from south swell magnets, but still quite good across Northern NSW.

Winds are expected to veer back to the W/SW so it’ll be clean at most beaches (perhaps a slightly southerly wobble at exposed northern ends). 

Yesterday’s and this morning’s satellite passes have confirmed wind strengths around the low in the south-eastern Tasman Sea with up to 50kts within the core fetch. The leading edge of the new S/SE tending SE groundswell is expected into the Mid North Coast around late morning Saturday and will build rapidly here through the afternoon. However, locations further north will see a later arrival time - and thus later upwards trend - and there is a slight degree of concern that Far Northern NSW and (even more so) SE Qld may not see an appreciable kick in size until very late in the day.

I still think we’ve got a good chance of seeing some strong surf filling in through the afternoon here, but this risk needs to be highlighted. 

How big? South facing beaches south of Byron should see 6-8ft sets late in the day, and with the swell direction veering from the S/SE to the SE there’ll be great options (though smaller) across the regional points and reefs that can handle these kinds of swells. It’ll be smaller and more manageable at protected southern corners. 

In fact, with confirmed core winds of 50kts (although not aimed perfectly in our direction), we are likely to see peak swell periods push higher than the 13.2 seconds currently modelled for 6pm Saturday (as per our Coffs Harbour forecast). My calculations are for somewhere in the 15-16+ second range, and this should push surf size higher at reliable offshore reefs.

Size will then ease through Sunday with light to moderate W/NW thru’ NW winds. This is a slight concern for the points so you’ll probably want to make the most of Saturday afternoon’s push. Early morning could be of a comparable size to late Saturday - say, somewhere in the 6ft+ range at south facing beaches and smaller elsewhere - but more so in the Far North than the Mid North. Size will lose two or three feet during the day. 

As for SE Qld, this new swell should produce quality 2-3ft surf across the outer points by late Saturday (much smaller early Saturday), and up to 3-5ft at south facing beaches and exposed northern ends.

Expect a similar size early Sunday but easing throughout the day. Sunday’s winds will favour the beach breaks but early morning should have clean options on the outer points. 

Next week (July 24th onwards)

No changes to the outlook for next week either, as per Wednesday’s notes. 

We’ll see lingering though easing SE swell early Monday (3-4ft+ open beaches in Northern NSW, 2-3ft exposed northern beaches in SE Qld, smaller on the outer points), and mainly light variable winds. Size will ease throughout the day across all coasts.

A small south swell is due on Tuesday from a strong but poorly aligned front exiting eastern Bass Strait overnight Sunday. I’m a little less keen on this now so will peg size at an inconsistent 2ft+ across south facing beaches south of Byron. It'll be very small away from open south facing beaches by this time; this is a low confidence pulse so don't work around it.

Of much more interest is a broad, powerful polar low tracking under Tasmania around Sunday that’s expected to spin off a series of trailing fronts through the rest of the week. These systems will supply varying degrees of long period south swell from Wednesday thru’ Friday. 

At the moment, Wednesday is expected to see the best waves from this pattern, with a rapidly building S’ly groundswell in Northern NSW that should provide 3-5ft sets at south facing beaches but much smaller elsewhere due to the steep swell direction. It’ll be clean too with W’ly winds. However we won’t see much size in SE Qld away from south swell magnets. 

More S’ly swell its expected through Thursday and Friday though there’s a risk of a developing S/SW flow as the associated front clips the coast. 

Have a great weekend, see you Monday!