South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Monday 13th April)

Best Days: Tues/Wed: strong southerly swells for Northern NSW, only small in SE Qld. Fri: good SE swell for Northern NSW with NW winds (only small in SE Qld). Sat/Sun: steadily building S'ly swells all weekend, easing Mon. Only small in SE Qld. 

Recap: Saturday saw easing E’ly swell throughout SE Qld in the 2-3ft range, with smaller surf south from about Byron. Winds were NW so the northern ends of open beaches were best. Saturday’s E’ly swell eased to 1-2ft on Sunday, and winds freshened from the south (following an early SW breeze) ahead of a late building S’ly swell across south facing beaches in Northern NSW, that pushed 4-6ft by the end of the day. Today has seen a combo of short range and long range S’ly swells provide solid 4-6ft surf to south facing beaches south of Byron, and conditions have been clean with light offshore winds.  SE Qld saw much smaller, slower surf around the 2ft to nearly 3ft mark though south swell magnets on the Gold Coast saw the odd bigger set. 

Slightly overhead sets at The Pass this afternoon - impressive for a straight southerly swell!

This week (Apr 14 - 17)

Strong fronts have been pushing through the lower Tasman Sea all weekend, and they’ll provide plenty of south swell for the next few days.

And fortunately, we can look at Southern NSW as a proxy for our immediate swell trends. Wave heights have held in the 4-6ft range at most south facing beaches today, with a handful of swell magnets pushing well north of this at times. 

This energy is already filling in across the Mid North Coast this afternoon and should reach the Northern Rivers overnight, but will ease slowly through the day. So, south facing beaches south of Byron should manage 4-6ft surf again on Tuesday morning (smaller at beaches not open to the south), with inconsistent 2ft to maybe 2-3ft surf throughout exposed SE Qld regions (maybe a few bigger sets at south swell magnets on the Gold Coast).

Expect wave heights to gradually ease through the day, losing a foot or maybe two. Conditions should be clean just about everywhere with light winds and weak afternoon sea breezes. 

Late in the day, a strong secondary pulse is expected to reach the Lower Mid North Coast, originating from a front/low combo positioned SW of New Zealand’s South Island this morning. This swell will then fill into remaining Northern NSW coasts on Wednesday, and should be slightly larger than Tuesday’s swell - though only just - peaking in the 5-6ft+ range at south facing beaches south of Byron, with 2-3ft surf across exposed SE Qld beaches/outer points and bigger sets near 3-4ft at south swell magnets on the Gold Coast. A slight easing trend is expected through the day.

The swell direction associated with this pulse will be slight S/SE of S, so it should provide a little more coverage across the coast than today’s (and tomorrow’s) energy. Ordinarily a fetch of this strength would have surf size pegged a little lower than what I’ve mentioned above, but the main factor in bumping up wave heights is the pre-existing sea state (generated by the weekend’s fronts) that means the follow up systems are working on an active ocean, which means we get a little more bang for our buck. 

Surf size will then steadily abate through Thursday, with south facing beaches south of Byron easing from 3-4ft+ to 2-3ft (and much smaller surf in SE Qld). Early light winds are expected to freshen from the north through this day, which will probably spoil surf conditions though there should be a few hours of clean conditions early morning. 

However, the afternoon is on track for an unusual S/SE thru’ SE groundswell to arrive, generated by the same front responsible for the late Tuesday/Wednesday SE swell. This front is expected to merge with a small polar low to the east - encapsulated within the broader Long Wave Trough dominating New Zealand longitudes - and we’ll see a rapid deepening of this low just the S/SE of New Zealand overnight into Tuesday morning (see below). 

The associated fetch will be slightly off-axis from our swell window, and a reasonable distance away - but we’re looking at peak swell periods in the 15+ second range arriving very late Thursday afternoon and building towards an overnight peak, before easing slowly through Friday (note: this swell isn’t showing properly on the charts either).

As such, the last hour of light on Thursday (south from about, say, Coffs), and early Friday (everywhere else in Northern NSW), are on track for the most size from this system. We should see a broad spread of surf around the 3-4ft mark south from Byron Bay, but I wouldn’t be surprised if one or two locations pull in larger waves, thanks to the lengthy swell periods - though this is more likely in Southern NSW than Northern NSW. Set waves will also be extremely inconsistent, and I’m not expecting much size in SE Qld, just a couple of feet at exposed northern ends. 

Winds will be around to the NW as a front approaches from the west, so there’ll be good beachies on offer to finish the working week. 

This weekend (Apr 18 - 19)

Another complex, amplifying node of the Long Wave Trough will approach from the west later this week, delivering westerly gales across the Tasmanian region. 

The associated surface features will enter our various acute south swell windows in a staggered fashion (see below), mainly on Friday as W/SW gales exit eastern Bass Strait, and the parent low slides just south of Tasmania with 40-50kt fetch aimed off-axis from our swell window, but within reach of providing a decent spread of southerly swell along the NSW coast. This will certainly be the case by Saturday as the associated front tracks into the lower Tasman Sea. 

As such we’re looking at a series of overlapping southerly swells all weekend. 

Saturday morning will initially see small residual swells from Friday (best suited to Northern NSW) ahead of the first pulse of S’ly swell from the fetch exiting eastern Bass Strait, that should reach the Mid North Coast into the afternoon with 3-4ft sets at south facing beaches south from about Coffs Harbour. 

This swell will fill in overnight, but it’ll largely be overtaken by the main S’ly swell from the parent low, that’s expected to generate 5-6ft+ sets at south facing beaches south of Byron on Sunday. I'm not confident on the specific timing just yet but the trend looks very likely to be this way (assuming model guidance doesn't move around a lot between now and then). 

SE Qld won’t fare well from this pattern so expect very small surf at most beaches, away from a handful of reliable south swell magnets. 

At this stage local conditions look OK under a ridge of high pressure (early SW winds tending moderate S’ly then SE, but this is still quite some time away so we’ll need to closely monitor the model output over the coming days. 

Next week (Apr 20 onwards)

Early next week will probably see easing size from the weekend’s south swells, ahead of the next Long Wave Trough that’ll renew strong south swell during the middle to latter part of next week.

See you Wednesday!