South East Queensland and Northern New South Wales Surf Forecast by Ben Matson (issued Wednesday 16th December)

Best Days: Thurs onwards: building E'ly swells with fun waves across most coasts; though Thurs/Fri will see tricky winds at times for the open beaches. Biggest and best waves due late Sun/Mon/Tues with light morning winds. 

Recap: Tiny lacklustre surf over the last few days, coming in just under size expectations, and exacerbated by a very low period and subsequently weak energy. 

This week (Thursday 17th - Friday 18th December)

Major revisions are required for the impending easterly swell this week, which is a bummer.

I had been following model updates since last Friday when there were positive signs of development in our eastern swell window, culminating in Monday’s model runs which strengthened the outlook in favour of a significant swell event building Thursday and Friday, easing slowly from Saturday. 

Unfortunately, whilst the broader synoptic pattern remains intact (large slow moving Tasman high), we’re now no longer expecting a coastal trough to form, which was expected to squeeze the pressure gradient even further and generate a couple of days of large waves on top of an otherwise moderate trade swell event.

Additionally, the ridge is expected to shift a little further north meaning the predominant trade flow will be aimed more up into the Coral Sea (to begin with). Therefore, not only will wave heights be considerably smaller than Monday’s notes alluded to, the biggest waves will be confined to the Sunshine Coast, with smaller surf as you track southwards along the East Coast.

SE Qld: We’re looking at building E’ly swells all day Thursday, reaching a peak on Friday with 2-3ft sets on the Gold Coast and 3ft+ sets across the Sunshine Coast. It’s essentially a fairly bog standard summer trade swell pattern, and freshening SE tending E/SE winds will limit the best waves to the outer points and other locations not too heavily sheltered from the swell direction. But there'll be fun peaky waves on offer.

Some locations may see early periods of light SW winds (i.e. southern Gold Coast) but for the most part expect bumpy surf across the open beaches. Thursday morning is likely to start a little slow but there should be plenty of energy pushing through into the afternoon.

Northern NSW: We have the same inbound trend as per the SE Qld coast but with a little less size as you head southwards. The Far North Coast is looking at a similar size as per the Gold Coast (2-3ft surf from the border down to about Ballina). Expect smaller waves south of here although winds will be more favourable - early light variable flow with freshening NE sea breezes in the afternoon.

The wind regime north of Yamba is likely to be more influenced from the ridge across the Tasman Sea; that is, mainly moderate to fresh SE to maybe E/SE winds but with brief, localised periods of light SW winds early mornings (mainly north of Byron).

This weekend (Saturday 19th - Sunday 20th December)

No major changes expected to Friday's swell regime into the weekend. If anything, we may see a very small easing trend as the ridge reorientates itself across the Northern Tasman Sea - leading to a slightly bigger east swell early next week - but there’ll still be fun trade swell all weekend, best suited to the SE Qld coast.

Synoptic winds don’t look like they’ll be very strong either, so all regions can expect early light offshore and moderate sea breezes throughout the daytime.

Wave heights should hold somewhere between 2ft and 3ft between Ballina and the Gold Coast, with smaller surf south to the Mid North Coast but larger surf (3ft+) across the Sunshine Coast beaches. Model guidance has a minor dip in size later Saturday and early Sunday ahead of a rebuilding trend Sunday afternoon but at this stage it’s too hard to be confident in any specifics (though don’t be surprised if the late session Sunday punches above forecast expectations). Let’s refine this in Friday’s notes. 

Next week (December 21st onwards)

The easterly fetch south of New Caledonia looks like it’ll be better aligned for a decent renewal of east swell on Monday. What’s also tipping this in favour of being a really good swell event is the stationary nature of the fetch - this is sometimes even better than a deeper, stronger low pressure system with stronger core winds, because stationary systems are given more time to build up a “fully developed sea state” which results in a much more consistent swell event, with a broader coverage of size and energy. And, these swells tend to be slow burners; that is they ease much more slowly than swells originating from independent low pressure systems that have tracked across or through the swell window. 

At this stage the fetch is expected to weaken slowly through the first half of next week, though it’ll remain active within the swell window until at least Wednesday. So, we should see waves all week however Monday and Tuesday look like they’ll see the most size.

We're looking at a peak on Monday, holding into Tuesday with 3-4ft sets across the Gold Coast and 4ft+ surf across the Sunshine Coast. As per the weekend's swell, we’ll see easing size south of about Ballina or Yamba however the good news is that - apart from the Mid North Coast - synoptic winds are expected to remain light, so we’re looking at great conditions in the mornings, with afternoon sea breezes unlikely to cause too many issues after lunch. 

The Mid North Coast is at risk of fresh NE winds late Sunday and Monday, but an advancing trough on Monday may disrupt this flow, leading to light variable winds and sea breeze Tuesday and Wednesday (albeit on the backside of this east swell).

Otherwise, the only other sources of swell into the long term is a fresh southerly pulse due later Tuesday or Wednesday (across south facing beaches in Northern NSW), originating from a powerful Southern Ocean low expected to develop south of Tasmania on Sunday evening. This could provide anywhere between 3ft and possibly 5ft surf to exposed south swell magnets south of the border, with some smaller followup S/SE swell later in the week from a later incarnation of the same system, near New Zealand. Let's reevaluate this in more detail on Friday. 

I'll also be keeping an eye on the aforementioned trough advancing northwards along the Southern NSW coast on Monday. Model guidance isn’t particularly encouraging right now but there is a chance this stalled system could lead to the development of a more significant system just off the east coast mid-late next week. I’ll have more on the chances of this in Friday’s updated forecast.