Persistent southerly swell on tap

Ben Matson picture
Ben Matson (thermalben)

Southeast Queensland and Northern New South Wales Surf Forecast by Ben Matson (issued Wednesday 18th June)

Best DaysThurs: easing S'ly swell early, best in the Lower Mid North with light winds here. Fri/Sat: fun S'ly swell with good winds (don't expect much size in SE Qld). Sun/Mon: couple of pulses of small, inconsistent S/SE tending SE swell, generally good conditions.

Recap: Small easing E’ly swell and a strong easing S’ly swell on Tues. Rebuilding S’ly swell today across Northern NSW, that hasn’t done much north of the border (away from the south swell magnets).

This week (June 17-20)

Southerly swell will continue to be the dominant force across the region for the short term. Wave heights are currently easing across the southern NSW coast, and will trend downwards in the north through Thursday.

However, a series of strong fronts have been powering through the lower Tasman Sea over the last day or two and although not very well aligned for the East Coast, are generating a series of southerly groundswells that’ll impact from late Thursday (in the lower Mid North Coast) through Friday (Northern NSW and exposed south facing beaches in SE Qld).

Surface conditions on Thursday will generally favour the Mid North Coast, as a weaker pressure gradient will result in light variable winds here (across the North Coast and SE Qld region we’re looking at moderate SW tending S’ly winds). In all regions, the early morning will offer the best surf anyway.

The new south swell expected for Friday won’t push up much more than 2-3ft at south facing beaches for the morning (in Northern NSW), but winds are expected to be light and variable tending N/NW, so exposed beaches should be pretty good. A second, slightly stronger pulse of S’ly groundswell should kick wave heights up by a foot or more into the afternoon - again favouring south facing locations - and with good winds there should be some really nice waves on offer. Just don’t expect much size in SE Qld away from the swell magnets, or at sheltered spots in Northern NSW. 

This weekend (June 21-22)

The weekend’s looking pretty good all round. Friday’s south swell will ease slowly through Saturday but exposed south facing beaches should still see early 3ft+ sets across Northern NSW (smaller at sheltered locations, and much smaller across most SE Qld beaches). Conditions are looking pretty good for the open beaches with moderate W’ly winds becoming light and variable into the afternoon.

On Sunday, a new pulse of S/SE groundswell will push into the region, originating from a polar low expected to form well south of New Zealand tonight and merge with the tail end of the fronts generating the S’ly swell expected on Friday. 

In fact, this polar low is expected to undergo several areas of intensification over the coming days - one immediately south of New Zealand and a second to the south-east (see chart below), which will maintain small levels of SE groundswell into the start of next week. No major size is likely from this source (say, very inconsistent 2-3ft+ sets at south facing beaches) but in the absence of any other swells there should be fun waves at most exposed beaches.

Wind wise, we’re looking at a weak trough developing across the western Tasman Sea over the weekend. This is likely to swing Saturday’s W’ly breeze around to the SW on Sunday, but without any major strength. I’ll fine tune these estimates on Friday. 

Next week (June 23 onwards)

As discussed above, we’ve got a second small inconsistent SE groundswell on target for Monday that should keep exposed beaches flush with small rideable waves (somewhere in the 2ft+ range, with long breaks between sets).

Looking beyond this, and a very vigorous frontal passage is expected to cross the SE corner of the country through Tuesday that will strengthen westerly winds about the region. At this stage, the models are favouring a northern storm track - mainly over the continent - but it’s likely that the swell window will finally become active through Tuesday afternoon, resulting in an upwards trend in south swell that’s likely to peak Wednesday afternoon or perhaps even Thursday. It’s too early to pin down specifics but at this stage it’s highly likely that our attention will be focussed on southerly swell for much of next week. And I wouldn't rule out the models shifting the storm track further south, which could significantly increase the current model projects of around 4ft at south facing beaches on Thursday (and could also bring forward the timing of the peak too).

Just one other region to put on the radar for next week - the tropical South Pacific, south of Fiji. A stationary high east of New Zealand and a broadening area of low pressure across Fijian longitudes are expected to moderately strengthen the trades in this vicinity, and while not currently on target for any major developments, is certainly worth keeping an eye on in the event that the models upgrade things. I’ll have a closer look on Friday.