It came (or, is coming) from the south!
South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Monday 19th August)
Best Days: Tues/Wed: pulsey south swells in Northern NSW (very small in SE Qld) with generally good winds. Could be a small sneaky E/SE swell in the mix across SE Qld though. Thurs/Fri: very large S'ly swell across Northern NSW, even some decent size in SE Qld by Fri, with fresh W/SW winds tending gusty S'ly some time late Thurs - holding into Fri across all coasts. Sat: large though easing from the south in Northern NSW (much smaller in SE Qld), with light winds tending N'ly later.
Recap: Small southerly swells persisted across Northern NSW all weekend, either side of 2ft at beaches with good southerly exposure, though SE Qld remained tiny. Winds were generally out of the northern quadrant, however many locations saw NW winds through the mornings. Today has seen wave heights ease right back though there was a small signal of NE windswell across the lower Mid North Coast this morning (Southern NSW picked this up much more efficiently). A S'ly change pushed up the coast during the day and we have started to see size build from the south.
This week (August 20 - 23)
An active frontal passage across the SE corner of the country will drive W/SW gales through our acute south swell window for the next few days.
We’re just starting to see the early signs of fresh southerly swell activity across Southern NSW, and this will translate to a slow building trend across the entire NSW coast through Tuesday and Wednesday ahead of step-ladder increases into Thursday and Friday.
Tuesday, Wednesday and early Thursday will all be under the influence of a moderate W/SW airstream across the Mid North Coast, in association with the fronts, all thanks to the axis of the Long Wave Trough being positioned over the mainland. Northern regions (SE Qld, Northern Rivers etc) will however see much lighter, more variable winds and afternoon sea breezes - in fact lingering moderate SW winds are likely early Tuesday morning.
As the LWT pushes east into the Tasman Sea later Thursday, we’ll see the wind direction veer more S’ly on its back flank, and this will in turn create a large short range secondary S’ly swell on top of the existing S’ly groundswells (see below).
This means relatively clean conditions across most coasts until sometime Thursday afternoon, when the southerly will kick in at strength across the Mid North Coast, extending through the the Far North Coast overnight and into SE Qld. The accompanying swell increase will be of great significance for exposed beaches south of the border.
As for size, Tuesday and early Wednesday should see wave heights fluctuate anywhere between 3ft and 5ft across most south facing beaches south of Byron, with smaller waves at beaches not directly exposed to the south. Keep in mind that there’ll be multiple pulses embedded in this pattern over the course of the two days so there’ll be both active and inactive periods of surf.
Across SE Qld, we won’t see much size at most beaches from this source - building to perhaps a slow 1-2ft across the Gold Coast outer points, however exposed northern ends and south facing beaches should push 3ft+ at times. Expect smaller surf across the Sunshine Coast.
As a side note, we’ll also see smaller SE and E/SE swell in the water over the coming days from a couple of seperate fetches that developed off New Zealand’s West Coast over the weekend. They'll be barely discernible in Northern NSW, but there was a third sneaky E/SE fetch off the northern end of New Zealand yesterday and today (see below) that has the potential to produce a few rogue 2-3ft sets across SE Qld beaches later tomorrow and into Wednesday. Don't bank on anything amazing though.
On Thursday, we’ll really start to see surf size increase through the day - initially across the Mid North Coast - before wave heights max out on Friday. South facing beaches south of Byron could reach 8-10ft at times (early Friday), and the outer SE Qld points will be your best option for a surf with sets around the 3-5ft mark under moderate to fresh SW tending S’ly breeze. Expect smaller surf at the more sheltered points. Winds will ease steadily into the afternoon too.
This weekend (August 24 - 25)
Saturday morning has a lot of potential, with a rapidly easing S’ly swell from 6ft+ across Northern NSW (3ft outer SE Qld points, also easing) however a small pre-frontal trough is forecast to develop across the region and we may see northerly winds into the afternoon. We should see light winds through the morning though. Let’s take closer look at that in Wednesday’s update.
Surf size will ease throughout Saturday and continue to trend down into Sunday, ahead of a possible small late pulse of S’ly swell from a minor front entering the lower Tasman Sea on Saturday. Either way we’ll be back to exposed beaches to finish the weekend, with very small conditions returning to SE Qld (exposed northern ends should see rideable waves though).
Next week (August 26 onwards)
Sunday’s small late new S’ly swell should persist into Monday across Northern NSW (3ft+ sets), before easing into Tuesday.
Long term model guidance is suggesting a series of small background S’ly groundswells for Northern NSW, originating from transient lows passing well to the south of Tasmania, though present indications are for minor energy in general.
No synoptic system of any significance is expected within the Tasman Sea at this point in time, though I’ll be keeping an eye on the weekend’s trough, which may linger off the SE Qld coast into the start of next week and could possible evolve into a swell generating system.
More on this in Wednesday’s update.