South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Wednesday 30th June)

SE Qld Forecast Summary (tl;dr)

• Extended period of trade swells, building from Thurs
• Strong, sizeable peak late Sun/Mon
• Easing from Tues but holding through until next weekend
• Tricky winds late Thurs/early Fri and maybe Sat, otherwise favourable 

Northern NSW Forecast Summary (tl;dr)

• Long period S/SE swell across south facing beaches south of Byron on Thurs
• Extended period of trade swells, building from Thurs
• Large peak in size late Sun/Mon
• Easing from Tues but holding through until next weekend
• Tricky winds late Thurs/early Fri and maybe Sat, otherwise favourable 

Recap

Conditions were mixed on Tuesday with moderate to fresh SW tending S/SE winds in some parts, even E/SE breezes across the Northern Rivers. A solid south swell produced 4-5ft sets at south swell magnets south of Byron but was much smaller elsewhere, especially SE Qld. However, trade swells built through the day and have reached 3-4ft this afternoon (smaller south from Ballina), with variable winds creating pockets of fun, if slightly lumpy surf at many regions. The Sunshine Coast is the outlier, and has seen a little more strength in the regional synoptic onshore flow, with ordinary conditions away from sheltered spots. A new long period S/SE groundswell (tp up to 19 seconds!) is pushing up the Southern NSW coast and should reach Northern NSW overnight. 

Byron Bay picking up some fun waves Wednesday morning

Late Wednesday lines at Snapper

This week (July 1 - 2)

Our incoming S/SE groundswell should plateau across Northern NSW on Thursday.

Because of the source of the swell - south of New Zealand on Monday - this afternoon’s size across Southern NSW provides a useful proxy for Northern NSW, so expect set waves between 3ft and 5ft at locations with good southerly exposure. 

However, the good news is that there’s a building E/NE trade swell in the water and this will compensate for those locations not picking up the S/SE swell. In fact, the trade swell will be a similar size throughout SE Qld on Thursday (3-5ft most open beaches and outer points), pushing a smidge higher on Friday - though I’m still not sold on the prospect of solid 6ft sets. Maybe the odd bomb set at a couple of exposed locations, but certainly not a broad representation of regional surf heights. 

As for conditions, we’ve got a broad high straddling New Zealand, and it’s expected to create a few issues for us as it butts up against a coastal trough of low pressure. 

The position of the trough is paramount as to how surface conditions will play out, as it'll be moving slowly west to east, pushing offshore into the weekend. The general feeling is that over the next two days, we’ll probably be under the effects of N/NE breezes, though the riskiest time will be Thursday afternoon overnight into Friday morning, and the riskiest location (for adverse conditions) will be south from Byron to about Coffs Harbour. 

Either side of this - i.e. Thursday morning and Friday afternoon - we stand a better chance for periods of light variable winds, and thus cleaner conditions, though potentially wobbly. And SE Qld coasts will probably see a little less strength in the wind overall, compared to its southern brethren. 

Of course, low pressure troughs are notoriously difficult to have confidence in and it’s likely there’ll be a broad range of conditions across the region (compared to trade swell size, which should remain relatively uniform). However, early Thursday and Friday afternoon are worth your attention. And we might get lucky at other times too. 

This weekend (July 3 - 4)

The weekend looks really good.

The coastal trough should create light variable winds across most regions on Saturday, though northerlies remain a risk (particularly SE Qld and Far Northern NSW).

A developing low pressure system within the trough line (by Saturday, sitting well off the coast) will slide to the south, and bring about a southerly wind change across the region on Sunday, initially the Mid North Coast before dawn, then Northern NSW by mid-morning and SE Qld by lunchtime. 

A stationary ridge across the Northern Tasman Sea should maintain punchy 4-5ft+ surf across most coasts on Saturday, however the developing low along the trough line will strengthen the head of the easterly fetch (feeding into the trough), and bring about a bigger pulse of E/NE swell for Sunday and Monday. 

This is expected to reach a peak in and around the 6-8ft+, probably concentrated across Northern NSW (especially the Mid North Coast) with a little less size into SE Qld, specifically the Sunshine Coast. But only a bit… wave heights will be very solid, everywhere.

I really need a few more days to firm up the wind outlook, as confidence is pretty high in the surf department. Regardless, Sunday’s shaping up to be only suitable for sheltered spots and points; Saturday looks tricky as wave heights will probably be at the upper end of the size threshold for the open beaches. 

Either way.. good times!

Next week (July 5 onwards)

Monday’s peak in E/NE swell (source below) will be biggest across the Mid North Coast (6-8ft+), with smaller but still-strong 5-6ft+ surf at exposed beaches in SE Qld. Size will trend down slowly through the day.

Even better, Sunday’s fresh southerly flow will quickly abate as the low (within the trough line) moves quickly to the south. So, expect light winds all ‘round.

Despite the easing trend, the ridge across the Northern Tasman Sea - stretching out into the South Pacific - will remain active until next Wednesday or Thursday. That’s the same fetch already in place, which means it’ll remain a swell generating machine for more than a week. And thus, will pump out swell into next weekend (albeit smaller in size). 

Ball park size range for most open coasts is 5-6ft+ early Tuesday, 4-5ft Wednesday, 3-4ft Thursday and then holding 2-3ft+ from Friday into Saturday. 

At the same time, we'll see southerly swells build across the region early next week, initially from the fetch related to Sunday's change, and then from several small low pressure centres embedded at the bottom of the trough line. However this will mainly favour Northern NSW and not SE Qld. 

Conditions look pretty good all week with no major strength expected in the wind throughout Northern NSW. We may see a brief period of S’ly winds in SE Qld around Tuesday as a weak ridge sets up through the Coral Sea but this will be great for the points anyway. 

All in all, a pretty fantastic run of surf coming up for the region.

See you Friday!