Easing S'ly swell and a small trade swell; then lots of S'ly swell next week

Ben Matson picture
Ben Matson (thermalben)

South East Queensland and Northern New South Wales Surf Forecast by Ben Matson (issued Wednesday 29th July)

Best Days: Thurs: easing south swell in Northern NSW with good winds. Tues/Wed: possibly a solid S'ly swell in Northern NSW, small in SE Qld. Thurs/Fri: large S'ly swell in Northern NSW, small in SE Qld.

Recap: Aside from the shark sightings, it’s been a productive couple of days of south swell. Wave heights came in pretty much bang on forecast expectations, with small waves across SE Qld but 4-6ft sets at south facing beaches in Northern NSW. With winds holding from the SW quadrant the best surf was found at semi-exposed points. This south swell is now easing across the coast.

This week (July 30 - 31)

The southerly swell of the last few days will steadily ease in size over the coming days. Thursday may see a few lingering 3-4ft sets at south facing beaches in Northern NSW early morning (mainly the Far North) but it’ll be smaller elsewhere, especially in SE Qld. 

SE Qld should also see a minor trade swell in the water over the coming days, generated by a strong ridge through the Coral Sea. It’s poorly aligned within our swell window, but covers a wide expanse so we should see some small energy spread back into the coast. I doubt we’ll see much more than inconsistent 2ft+ sets across there Sunshine Coast, and smaller surf is likely across the Gold Coast (1-2ft) but there’ll be a few small waves on offer. Very little trade swell is expected across Northern NSW, of which the easing south swell will be dominant anyway. 

Thursday’s winds look pretty good just about everywhere, just light offshores and weak afternoon sea breezes. 

On Friday, the south swell will become quite small across Northern NSW, probably about the same size as the trade swell (1-2ft at swell magnets) but it’ll trend downwards during the day. The trade swell should also kick along the size size range as per Thursday but I can only see the Sunshine Coast benefiting in any major way. 

As a side note, a small long period southerly swell is expected to clip the Northern NSW coast during Friday (the leading edge may show across the MHL buoy network with Tp around 18 seconds) but no great size is expected to eventuate at the coast - probably no more than infrequent 1-2ft bombs at a couple of reliable south swell magnets. The source of this swell is an intense polar low located well south of the continent several days ago, and its poor alignment within our acute south swell window - and the very large travel distance - means that only a handful of select locations will see any energy, and even then there’ll be very long breaks between the sets. 

An approaching front will swing overnight N’ly winds (strongest in the south) around to the NW so most open beaches should have a few clean waves on offer. However, wave heights will be very small at most beaches. 

This weekend (August 1 - 2)

The weekend looks tiny. Most regions are looking at residual energy from the south, with SE Qld likely to maintain small levels of trade swell in the 1-2ft range, occasionally bigger on the Sunshine Coast.

As per last weekend the source of this trade swell is distant, disjointed and not particularly strong so the surf won’t be very powerful and it’ll also be quite lully at times. But conditions should be clean on Saturday with light winds, ahead of a freshening northerly throughout Sunday

The only other swell source is a small refracted south swell from about mid-Sunday onwards, and probably only for the Mid North Coast (south of about Coffs). This swell will originate from a strong front exiting eastern Bass Strait on Saturday and may produce a few 2-3ft sets at reliable south swell magnets in the south late Sunday at best. I wouldn’t get your hopes up for anything worthwhile at this stage though.

Next week (August 3 onwards)

We’ve still got an incredible progression of deep low pressure systems lining up to smack the SE corner of the country this weekend and early next week. However, the initial series of lows look like they’ll remain just west of our swell window, which means we may not see an appreciable amount of size until later in the week, once the storm track finally clears to the east of Tasmania. 

At this stage Monday is expected to start off small, with a combo of persistent trade swell in SE Qld, some small short period south swell across exposed Northern NSW beaches, plus some small, long period refracted energy from the deep Southern Ocean.

Tuesday and most of Wednesday looks like they’ll be occupied by a building south swell originating from SW gales extending off the Southern NSW coast. Ordinarily, spreading south swells from these sources are flukey and unreliable however as we saw a few weeks ago, they can sometimes deliver the goods.

Right now the strength and direction of this SW fetch looks pretty good so I wouldn’t rule out the potential for some large surf for exposed south swell magnets in Northern NSW (say, 6ft+) at the height of the event, and possibly even some fun small peelers across open beaches across SE Qld (2ft, maybe 3ft). But, we need a few more days to have confidence in this scenario - these figures are certainly at the upper end of the posisble size range. 

The final low pressure system in this progression looks to round the Tasmanian corner late Tuesday and into Wednesday (see chart below) and should kick up a very large south swell for Thursday and Friday, possibly in the 6-8ft range at south facing beaches in Northern NSW, maybe even larger at offshore reefs (due to the associated large swell periods).

This swell should also produce small clean waves into SE Qld, although probably a fraction of the size in Northern NSW due to the swell direction (2-3ft seems a reasonable call at this stage, bigger at south swell magnets).

Most of this period will be accompanied by gusty SW winds, so conditions are likely to be quite challenging at exposed spots in Northern NSW - but it’ll be ideal for semi-exposed points. In any case, let’s reassess things on Friday with the availability of updated model guidance as there’s been a little to-ing and fro-ing in the models over the last few days, and we’re likely to see this pattern continue for the next few days until the specifics are firmed up.


Cylinders85's picture
Cylinders85's picture
Cylinders85 Thursday, 30 Jul 2015 at 10:26am

Any one feel the earth quake ?

Sprout's picture
Sprout's picture
Sprout Thursday, 30 Jul 2015 at 4:27pm

Yeah about a 10 second rumble/shake, thought they were being a bit rough getting the Dicky out, then heard it was an earthquake.

thermalben's picture
thermalben's picture
thermalben Friday, 31 Jul 2015 at 2:32pm

Just drove along the Tweed, there's some fun little waves on offer though it's hard to be confident if it's the long period south swell, or a small increase trade swell (looks more like the south swell to me). Set waves are 2ft+ and providing some really fun options under a light variable breeze.