South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Wednesday 15th April)

Best Days: Thurs: easing S/SE swell in the morning, then a late a'noon kick in new SE groundswell (mainly south of Coffs), peaking o'night, then easing Fri (only small in SE Qld). Getting bumpy Thurs with developing N'lies but Fri will be clean under a NW breeze. Sat/Sun: steadily building S'ly swells all weekend - solid at south swell magnets south of Byron on Sun - easing Mon. Tricky winds all weekend though.

Recap: Tuesday delivered a wide range of wave heights across the coast following an overnight renewal of S’ly swell. South facing beaches south of Byron managed 4-6ft sets, but it was much smaller elsewhere and SE Qld dipped out in the size department: Gold Coast south facing beaches were 3ft early (1-2ft elsewhere) with smaller options across the Sunshine Coast. Today started out smaller, and the expected increase in new S/SE swell through the day has arrived later than forecast, and fallen short of size expectations. Most south facing beaches south from Byron only managed 4ft+ sets, and it was pretty small throughout SE Qld, barely scraping the 2ft mark at exposed beaches. Conditions were clean both mornings with light offshore winds, ahead of moderate afternoon sea breezes. 

Nice lines at Coffs this morning

This week (Apr 16 - 17)

We’re looking at easing S/SE swells on Thursday, and freshening northerly winds will create some issues across the coast.

Initially, the early morning breeze should be more N/NW or even NW but it’ll straighten up from the north through the morning and this will blow out many beaches south of Byron. Wind strengths will be lighter north of the border, but it doesn’t take much to chop up exposed locations. 

Surf size will be declining anyway. South facing beaches south of Byron may see early stray 4ft sets but we’ll see a size drop to 2-3ft by the afternoon. Elsewhere, expect smaller surf, and across SE Qld there won’t be much size away from exposed northern ends and south facing beaches, which should scrape in around the 2ft mark if we’re lucky.

Sometime mid-late afternoon, I’m expecting the regional wave buoys (in Northern NSW) to have picked up the leading edge (15+ seconds) of a new SE swell generated by an intense low that formed S/SE of New Zealand on Monday - in actual fact, a merger between the low that generated our current swell, and a new polar low. 

This system intensified rapidly with surface winds reaching 40-45kts+, but it was located in a remote, flukey part of our swell window and only displayed a favourable alignment for a short period of time. As such, confidence is not especially high for this swell, and how much of the coast it’ll properly influence. In particular, I don’t think we’ll see a lot of activity north of the border. 

At this stage I’m still expecting south facing beaches south of Byron to up 3-4ft+ sets from this source - very inconsistent at times - though this swell may not show in the Far North until overnight. As such, Friday is a better choice to see the bulk size. 

And this is a good thing too as we’ll concurrently see winds veering back to the NW, cleaning up the wide open beaches. North of the border, exposed northern ends and south facing beaches will see the biggest waves, perhaps 2ft, maybe 2-3ft if we’re lucky but with long breaks between waves. It'll be much smaller elsewhere though, and the winds won't favour the outer points anyway.

This weekend (Apr 18 - 19)

We’ve got another amplifying node of the Long Wave Trough on the way. It’ll approach Tasmania later Thursday and push across the region more comprehensively on Friday, building a series of overlapping south swells throughout the weekend. 

The latest model guidance has slightly weakened the strength of the two primary fetches - one exiting eastern Bass Strait (providing Saturday’s waves) as well as the primary low tracking underneath Tasmania (providing Sunday’s waves), so I've pulled back wave heights a touch from Monday’s estimate. However, we’ll still see plenty of swell. And, I'm certainly forecasting a lot higher than our computer model is estimating. 

For the most part Saturday looks to see easing SE swells from Friday. South facing beaches in Northern NSW may see a few leftover 2-3ft sets at dawn but it’ll be down to 1-2ft by lunchtime. Expect smaller surf north of the border. 

However, this will be overtaken by a fresh southerly swell, only favouring south facing beaches (south of Byron) but likely to rebuild back to 2-3ft during the day. It’ll be much smaller elsewhere and we won’t see a lot of size in SE Qld at all. 

Sunday’s swell will be much stronger with longer swell periods north of 15-16 seconds, and wave heights should push 4-6ft at south facing beaches south of Byron. Of course if your beach isn't open to the south it'll be a lot smaller (southern ends will be very small). And I’m still not expecting much size in SE Qld though exposed northern ends and south facing beaches - mainly the Gold Coast - may pick up some 2-3ft sets into the afternoon. 

A couple of things on Sunday’s swell too: the flukey swell source means that we’ll see a much smaller spread of the upper end of this size range, compared to south swells generated by S/SW fetches parallel to the eastern Tasmanian and Southern NSW coasts. Fronts rounding the Tasmanian corner can often be hit and miss (for NSW surf prospects) but I really like the way this one projects from polar latitudes, it’s just a shame it’s not positioned a few more degrees to the east otherwise we could probably add another two or three feet on to these size estimates.

In any case, the weekend’s winds are looking a little tricky, thanks to a weak trough on Saturday that may evolve into a closed low on Sunday (off Southern NSW). This is showing all kinds of potential conditions (good and bad) throughout the weekend so we really need a few more days to firm things up. But there is certainly a risk that (in particular) Sunday’s favourable south swell may be wind affected. A windswell is also a possibility depending on how (or even if) this low develops.

Next week (Apr 20 onwards)

Sunday’s possible closed low could generate some punchy local swell for Monday (probably just Northern NSW) but it’s not yet clear whether this will eventuate. In any case, Sunday’s solid S’ly groundswell will be steadily easing by this time. 

There’s some modest activity happening north of New Zealand in the long term model runs but I’m once again sharpening my focus towards approaching frontal systems below Tasmania next week, that’ll likely maintain a steady stream of southerly swells for the middle to latter part of next week and onwards. 

See you Friday!