South-east Queensland and Northern NSW Surf Forecast by Steve Shearer (issued Wed 12th Apr)

Forecast Summary (tl;dr)

• S Swell persisting into Wed AM but easing; clean conditions with light winds. Expect much smaller surf north of the border.
• Moderate+ S/SE swell persisting across Northern NSW Thurs thru' Sat; only small in SE Qld but workable
• Sat the pick of the weekend
• Solid E/NE and S/SE swells building early next week as trough-block pattern establishes
• Keeping an eye on potential TC in Coral Sea off QLD coast, stay tuned for updates

Recap

Solid S swell energy favoured NENSW for size with sets to 4-6ft at S facing beaches under W’ly winds. A larger reinforcing pulse made it’s way up the coast yesterday a’noon with bigger 6-8ft sets at S exposed breaks but buoy data and observations showed it peaked overnight across most of the region. Today has seen easing swells with early 4-5ft surf now on the wane and SEQLD seeing more of the same 2ft surf with the odd 3footer as yesterday. Clean conditions early under a synoptic W’ly flow are now deteriorating under a NW-N flow. 

Smaller north of the border, but still some clean lines wrapping in

This week (Apr 12 - 14)

The broad, complex Tasman low which generated large S swells is now positioned on the other side of New Zealand with a lingering fetch of SSE-SE winds under the South Island. A much smaller, cut-off low NW  of Tasmania is linked via a trough line to TC Ilsa  off the Kimberly Coast and is expected to drift into the Tasman Sea tomorrow bringing a fresh S’ly flow to round off the week. A dynamic trough blocking pattern is then expected to unfold in the medium term. Details below. 

In the short run and variable winds through tomorrow up to lunch-time provide a window of clean-ish conditions before S’ly winds freshen through the a’noon as a trough deepens off the North Coast. Expect some N’ly scarring on the Points but beaches and S swell magnets should be clean. We should see swell direction come around a little more S/SSE tomorrow, offsetting the drop in wave period. Expect size in the 3-4ft range at NENSW S facing beaches, smaller 2ft at SEQLD S facing beaches. After lunch we’ll see a freshening S/SW flow with a little kick in size expected in NENSW, most of it coming from short range S swell of low quality.

Similar winds Fri with a S’ly flow expected through the day and only a brief window of lighter SW breezes for the early. The fetch below the South Island is expected to provide a rebuild in surf heights from the SSE, up into the 3-4ft range in NENSW, along with some short period local S swell with smaller 2ft surf north of the border at S facing beaches. 

This weekend (Apr 15 - 16)

Sat morning is looking pretty good with the North Coast low moving south and an approaching front bringing a morning W’ly breeze which should groom plenty of leftover SSE swell nicely. Expect 4ft sets early holding through the day in NENSW, smaller 2-3ft at SEQLD swell magnets. Light SW-W winds should tend to NE seabreezes in the a’noon.

Sunday looks like easing swells with 2-3ft surf at S swell magnets in NENSW, smaller sub 2ft surf in SEQLD, with the fetch out of Cook Strait being delayed in development by 12-24hrs compared to Mondays notes. Winds will clock around from NW through N and freshen  with a potential W’ly tilt across the MNC as the front passes into the Tasman. 

Next week (Apr 17 onwards)

As Ben highlighted in Mondays notes we have a very dynamic outlook into next week with a large ‘trough-block” pattern establishing through the Tasman Sea and possibly extending int the South Pacific swell window. There’s still substantial variability run to run and between models so we’ll be revising these estimates up or down on Fri.

For now, we should see a morning SW flow Mon before S’lies develop in the wake of the front, which is expected to quickly move away to the SW. SE-ESE swell from the late Cook Strait fetch supplies nice 2-3ft surf, with some local S swell also joining the mix later in the day.

Through this period we’ll see E’ly winds infeeding into the long trough line with good odds of a discreet low forming in the trough line between New Caledonia and the North Island. These winds are aimed directly at the East Coast over a broad area which should see widespread E’ly quadrant swell develop from Tues, along with SSE-SE swell from the winds through Tasman. GFS has backed down on windspeeds feeding into this broadscale trough/low pattern with wave models suggesting surf heights in the 4-5ft range from this source, likely pulsing around this level Tues-Fri.

Larger surf is still a possibility with EC model suggesting stronger windspeeds in the fetch and larger 5-6ft surf. 

So pencil in a few days of solid mixed E and SSE swell from Tues-Fri with winds looking mod S’ly although the presence of troughs makes winds look very fickle. We'll finesse all those details on Fri.

Complicating matters further GFS has been suggesting a Tropical cyclone forming in the Coral Sea early next week with a proposed S’wards movement, parallel to the coast. Latest GFS model runs look pretty terrifying if this coast hugging system comes into existence as modelled. 

Huge swells and destructive weather can’t be ruled out at this point. This is a long way off and thus subject to low confidence so check back in Fri and in the comments as we come to grips with this dynamic pattern.

Seeya then.