South-east Queensland and Northern NSW Surf Forecast by Steve Shearer (issued Wed Sep8)

SE Qld Forecast Summary (tl;dr)

• E swell slowly easing and becoming more inconsistent through Thurs/Fri, few small leftover Sat
• Long period refracted S swell Thurs
• Small S swell favouring NENSW later Sat/Sun but N'ly winds a problem
• More S swell next week, favouring NENSW,  stay tuned for details
• Possible E swell event later next week, check Friday for revisions

Northern NSW Forecast Summary (tl;dr)

• E swell slowly easing and becoming more inconsistent through Thurs/Fri, few small leftover Sat
• Longer period S swell  Thursday, easing Fri with increasing N'ly winds
• Small S swell favouring NENSW later Sat/Sun but N'ly winds a problem
• More S swell next week, stay tuned for details
• Possible E swell event later next week, check Friday for revisions

Recap

Strong cocktail of swells since Mon’s notes has impacted the region with exposure to S swell being the main differentiator in size between regions north and south of the border. Separating out the swell trains has been controversial but pulses of E’ly swell from the South Pacific source have over-achieved at Points and Bays with dominant, more proximate S swell very much over-shadowing the more inconsistent E swell pulses at most locations south of the Border. 

Yesterday was flat out pumping at most spots north of the border with excellent quality 3-4ft E swell augmented by strong S swell which added another 3ft to the mix. South of the border strong S swell was in the 6ft+ range with winds tending S’kly and freshening through the day surfing was mostly confined to protected spots.

Size has eased today from both sources with NENSW still seeing S swell in the 4-5ft range and inconsistent 3-4ft sets from the E with S’ly winds easing. Size in SEQLD was significantly down on yesterday with mostly 3ft surf, bigger at swell magnets where S swell kept wave heights topped up at 3-4ft. 

A very good run of surf for Spring.

This week (Sep 8-10)

Not much change expected from Mon’s f/cast notes apart from the timing on the expected long period S pulse over the next 24hrs. ASCAT (satellite windspeed) passes showed plenty of storm force winds associated with the deep low as it transited the Tasman overnight and into this morning. Compared to model runs on Mon the system has travelled a bit faster than forecast and this will reduce the duration of the swell.  Longer period and mid period S swell is expected to arrive overnight and provide some sets in the 4-6ft range at S facing beaches in NENSW, smaller 2-3ft in SEQLD. 

Light offshore breezes are expected in the morning before N’ly winds kick up later in the a’noon so you’ll want to get in early, or at least by lunch-time.

Remarkably, mid period energy from the E, caused by a persistent long E’ly tradewind fetch in the South Pacific, will still be chugging away in the background with both size and consistency slowly easing back. Expect some 2-3ft sets to continue but they’ll become few and far between through the day. If you’ve missed out, tomorrow is well worth downing tools for as the last real day of the swell.

There’ll be enough residual energy in the water Fri morning for a fun surf at exposed breaks- especially in NENSW - with a mix of S swell trains in the 2-3ft range and some stray E leftovers in the 2ft range. You’ll have to head to swell magnets or exposed northern ends in SEQLD to get a wave. Conditions will be best early with NW winds, expected to freshen from the north during the day before a shallow trough stalls somewhere on the Central or Mid North Coast, disrupting the northerly flow and with winds likely to become variable later in the day. Keep an eye on wind obs Fri a’noon but unless you have a good backbench handy it’ll be affected by the N’ly winds earlier in the day. 

This weekend (Sep 11-12)

The cold front transiting the Tasman through Friday weakens as it does so, but the fetch is strong enough to bring a small boost in surf from the South through Sat PM. High pressure quickly moves into the Tasman during Sat, and this the more seasonal variety:  transitory and located at sub-tropical latitudes. That means a more seasonal N’ly flow through Sat, with another cold front passing on Sun seeing pre-frontal N’ly winds freshening during the PM hours.

Expect small S swell Sat in the 2ft range at S exposed beaches in NENSW, building a notch during the a’noon. Expect 1-2ft in SEQLD S swell magnets, with early NW winds tending more N too NE during the a’noon. A much more typical Spring outlook than the one we’ve had so far in September. Keep expectations low, any small S swell is likely to be ripped to shreds by the N’ly winds. 

This swell eases back through Sun with leftovers in the 2-3ft range early, dropping back into the sub 2ft range and with freshening N’ly winds we’re likely a much more Spring-looking ocean than we have so far this September. Good time for ding fixing or diving.

Next week (Sep 13) and beyond

Models are still in major divergence for next week so it’s likely we’ll need some serious revision on Friday. We can block out the pattern now and revisit on Friday with hopefully more details.  We can book a late S’ly change in on Monday, courtesy of a frontal progression and low passing through the Lower Tasman on Sunday. This low is complex and multi-centred and major models are offering up very different resolutions as to the specifics and consequent surf potential. 

EC has a more deep southern fetch which would suggest a stronger S swell later Tuesday, but pushes a more proximate frontal fetch up the NSW coast Mon, driving a local, short range S swell increase late Mon, more likely early Tuesday.

GFS has a more disconnected system, with the low migrating into the Central Tasman as a weak low offering a small S swell pulse Tuesday. 

Both scenarios see winds tend to the SW then S late Mon with S’ly winds extending up the NSW coast during Tues.

The GFS scenario then offers a couple of days of small SE swell mid/late next week as the low loafs around near the South Island.

EC has a more dynamic scenario with a coastal trough of low pressure forming a surface low off the NSW North Coast on Wed 15/9 which then drifts East into the Tasman generating a major E through ESE swell for the region. 

We’ll just flag this scenario for now, it seems a bit of an outlier but with instability still high in the Tasman Sea we can’t discount it completely.

Check back Friday for a fresh look at it.