thermalben

Coupla (small) windows of opportunity

South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Monday 23rd November)

Best Days: Tues: possible window of OK conditions and peaky N'ly windswells across a handful of SE Qld and Far Northern NSW beaches (keep your expectations low). Thurs/Fri: small SE swell with light morning winds. Biggest in Northern NSW. 

Recap: Small E’ly swells across SE Qld and Northern NSW over the weekend were clean through the mornings with light winds, but the afternoons saw freshening northerlies. Surf size was smaller south from Yamba. Today has seen the northerly really pick up in strength and generate a local N’ly windswell across some exposed spots, though conditions are terrible.

Small on the Sunny Coast this morning

This week (Nov 24 - 27)

A complex trough is moving up the NSW coast this evening. However, the short term outlook is not clear for Tuesday morning, as it appears that a short-lived southerly wind change (into Coffs before midnight) will precede the main trough, which is expected into Coffs early/mid-morning, reaching the border around lunchtime.



As such, there’s likely to be a window of light winds ahead of the main change - though model guidance maintains the northerly flow across much of SE Qld through the early morning.

At first glance, this would appear to be a negative, but it’s actually a positive - we’re already seeing 2ft+ of local N’ly windswell right now (across the Southern Gold Coast, at least) and it should maintain this size, if not build a smidge more into Tuesday morning. 

This means once the wind becomes light (or the southerly pushes through) there could be some interesting N’ly peaks running sideways down the beaches. Max surf size will probably be somewhere in the 2ft to maybe 2-3ft range at a handful of north-facing swell magnets on the southern Gold and Tweed Coasts, with smaller surf everywhere else (Sunny Coast, and south from Byron). So, keep your eyes peeled and pounce if everything lines up. It's a low confidence event (and only a windswell anyway!), but could be OK.

In fact, the S’ly tending SE change is expected to stall upon reaching the Gold Coast Tuesday, and may not even make it north of Moreton Island until Wednesday. 

Anyway, a new Tasman Low will form to the east of Sydney over the coming days, in association with this southerly change. However the models have slightly downgraded this low in a few ways (size, strength) and also sped up its eastern transition, so I am going to marginally downgrade its size potential from several of its sources. 

The fetch trailing the southerly change will generate a brief flush of short range south swell for south swell magnets in Northern NSW on Tuesday afternoon, but accompanying fresh southerly winds will create bumpy conditions at those beaches picking up the most size late in the day (3ft+). Protected southern corners will be much smaller though cleaner and we probably won’t see much size north of the border on Tuesday.

Tuesday’s south swell will ease quickly into Wednesday (with abating S/SE winds south from Ballina), and despite a new ridge building into the Coral Sea, it doesn’t look strong enough to generate any meaningful swell for SE Qld. So, expect small surf across the outer points under a moderate to fresh S/SE breeze. 

Late Wednesday afternoon will see the arrival of a small new SE swell from the southern flank of the Tasman Low (see below). This should rebuild exposed beaches in Northern NSW back up into the 2-3ft range, though SE Qld probably won’t see much of an influence into Thursday.

Open beaches should maintain 3ft sets across Northern NSW on Thursday though it’ll be smaller throughout SE Qld, with 2ft sets at exposed beaches and smaller waves again along the points, though the wavelength will have drawn out by then so surf quality should be a little better. 

This swell should persist into Friday morning before gradually easing, and early light winds will freshen from the NE (Mid North Coast), E (Northern Rivers) and E/SE (SE Qld). 

So, in summary there’ll be small beaches on offer Thursday and Friday mornings across most coasts, and sometime Tuesday should offer a window of peaky N’ly swells across SE Qld and Far Northern NSW beaches. 

This weekend (Nov 28 - 29)

We have another weekend of small surf, and freshening northerly breezes. Though SE Qld should be spared the poor winds until Sunday.

As it is, there won’t be much surf anyway. Our small SE swell for the end of this week will be gone, and most of our usual swell windows look dormant. 

The only thing to keep an eye out for is a possible small south swell both days. A decent frontal system pushing under Tasmania this Wed/Thurs will generate a small south swell for Sunday, however model guidance actually shows a nice swell front pushing up into the lower Tasman Sea on Friday, glancing Northern NSW on Saturday morning - but this will originate from a stronger but poorly shadowed fetch to the south-west of Tasmania over the coming days (an earlier incarnation of the same system, see below). 

It’s a super flukey event, and I’m reluctant to put much faith in the chances of anything occuring, as it’s quite likely that most beaches will completely dip out - but there is certainly a chance that one or two reliable south swell magnets (probably just the Mid North Coast) could pick up stray 2-3ft sets from this source. I’ll take a closer look on Monday.

Sunday’s south swell looks even smaller, and equally flukey, and the wind will be hammering by then most likely.

Next week (Nov 30 onwards)

The models are still suggesting a series of strong fronts through the lower Tasman Sea throughout next week, resulting in a couple of decent south swells for Northern NSW. More on this in Wednesday’s update.

Comments

Rockethut's picture
Rockethut's picture
Rockethut commented Monday, 23 Nov 2020 at 6:52pm

That's disappointing.
I was looking forward to something along these lines from last week's update.

"Later next week is showing broad troughy signs for the Coral Sea and there is good easterly swell potential for next weekend and the following week. "

thermalben's picture
thermalben's picture
thermalben commented Tuesday, 24 Nov 2020 at 7:33am

Yeah, it is disappointing (though, not totally unexpected given the time of the year).

But to be fair, the same update also noted "a strong, active frontal sequence through the Tasman Sea during the following week, suggesting a sustained run of decent southerly groundswell for Northern NSW".

Right now, this pattern is still holding (reasonably) true. However, it the frontal sequence had been scrapped by the models and the troughy pattern had held in, I don't think there'd have been any disappointment from anyone!

I suppose it's a classic example how forecast accuracy (model, or human) is in the eye of the beholder. A thousand accurate forecasts for small swells and northerly winds is meaningless, but a single inaccurate forecast for a greatly-desired east swell is catastrophic.

And that's why I love forecasting!

rj-davey's picture
rj-davey's picture
rj-davey commented Wednesday, 25 Nov 2020 at 9:55am

so true...thanks for playing the mugs game Ben

donweather's picture
donweather's picture
donweather commented Monday, 23 Nov 2020 at 7:48pm

Spring is here!!

SDW's picture
SDW's picture
SDW commented Monday, 23 Nov 2020 at 10:54pm

My guess is it won’t be until about Christmas that anything noteworthy rolls through. At least for those of us north of the border.

_Bodhi_'s picture
_Bodhi_'s picture
_Bodhi_ commented Tuesday, 24 Nov 2020 at 6:57am

Yep, well I hope everyone has other sporting activities to keep them fit while we wait for the next proper swell, “come-on La Niña deliver more/some goods”

thermalben's picture
thermalben's picture
thermalben commented Tuesday, 24 Nov 2020 at 7:15am

Lumpy but totally workable N'ly windswell options on the southern Goldy this morning.



​​​​​​​

thermalben's picture
thermalben's picture
thermalben commented Tuesday, 24 Nov 2020 at 7:24am

Models picked up the short-lived overnight S'ly change well too, though the whole pattern is running a few hours ahead of schedule.

Last night's temporary S'ly change reached Coffs at 7:30pm (gusting 23kts at 9pm), but was then light and variable by 11pm, and winds remained calm until the main trough passed through at 4:20am (now gusting 20kts+ from the south).

We saw the same trend across Yamba - an hour of gusty southerlies from 10-11pm (gusting 37kt!), then light variable winds for a period of around six hours before the southerly resumed after 5:30am. Evans Head also picked up 37kt S'ly gusts as the initial change pushed through at 10:44pm, but it's been under 10kts since midnight, only resuming from the south at strength after 6:30am.

The S'ly change has recently pushed into Byron and should be at the border within the next few hours. 

Meanwhile, winds are light N'ly at Cooly, light NW at the Seaway, and light N/NW on the Sunny Coast.

More interestingly, Cape Moreton is currently gusting 32kts N/NW. Such a huge difference in wind strength across such a small longitudinal distance. 

AndyM's picture
AndyM's picture
AndyM commented Tuesday, 24 Nov 2020 at 8:29am

Had a look at the Bureau site this morning, was gusting 21 knots from the north at 2330 last night then 20 minutes later it was gusting 26 knots from the south.
Always fascinates me how suddenly and comprehensively winds can change - it's not like there was any gradual easing of the northerlies ahead of the change.

Island Bay's picture
Island Bay's picture
Island Bay commented Wednesday, 25 Nov 2020 at 9:57am

Andy, here's a little video from a mate of ours, showcasing the northerly and southerly gales of Wellington. It's a nutty place.

The last bit is a particularly vicious southerly that hit in March 2010.

Oh, and there's a quick glimpse of a local bombie.

https://vimeo.com/28807251

spidermonkey's picture
spidermonkey's picture
spidermonkey commented Wednesday, 25 Nov 2020 at 10:20am

Epic!

thermalben's picture
thermalben's picture
thermalben commented Wednesday, 25 Nov 2020 at 11:32am

Whoa! offshores @ 55s.

Island Bay's picture
Island Bay's picture
Island Bay commented Wednesday, 25 Nov 2020 at 11:59am

Quite common to have northerlies (offshore) gusting 60-70kts on that stretch of coast. And we have had both northerlies and southerlies gusting 100kts.

AndyM's picture
AndyM's picture
AndyM commented Wednesday, 25 Nov 2020 at 12:43pm

And how's that at 4.00??!!

It's like the arrival of Satan.

Craig's picture
Craig's picture
Craig commented Wednesday, 25 Nov 2020 at 12:51pm

That's crazy!

Island Bay's picture
Island Bay's picture
Island Bay commented Wednesday, 25 Nov 2020 at 1:54pm

Satan may or may not have been spotted at a local watering hole that evening.

It's good entertainment, aye. But don't forget we have to live this shit!

AndyM's picture
AndyM's picture
AndyM commented Wednesday, 25 Nov 2020 at 12:38pm

Thanks IB, great footage.
Pretty serious weather, and to think here on the east coast of Oz if we see a gust over 35 knots it's a big deal and makes the news.
60-70 knots is common?? That's the leading edge of an approaching low?
Jeez.
Maybe we need that here, might blow away some of the man buns if you know what I mean.

Island Bay's picture
Island Bay's picture
Island Bay commented Wednesday, 25 Nov 2020 at 1:59pm

Those big offshore gusts at 00:55 are actually under a big high. No shit.

Imaging a big blob of warm air moving across the Tasman from Aus, and a front approaching the South Island. The NW winds pile stable air (warmer aloft) onto the west coast, and it can't make it over the Alps, so it all streams though Cook Strait, is reluctantly lifted over the local hills, then comes roaring down off the steep coastal hills of Wellington South Coast.

thermalben's picture
thermalben's picture
thermalben commented Tuesday, 24 Nov 2020 at 8:59am

No wind on the Tweed at the moment. Slow windswells in the 1-2ft range at most beaches, borderline surfable. One or two spots looking OK with a little more size. Not sure if it'll hold for long once the southerly kicks in.

Rockethut's picture
Rockethut's picture
Rockethut commented Tuesday, 24 Nov 2020 at 9:28am

TOS was 0.5ft this morning, cold and dirty! Absolute rubbish at its best.
Seems like southern goldie was better this morning...

thermalben's picture
thermalben's picture
thermalben commented Tuesday, 24 Nov 2020 at 12:35pm

Looking fun across the Superbank.




thermalben's picture
thermalben's picture
thermalben commented Tuesday, 24 Nov 2020 at 3:50pm

Still.. just.. breaking... almost goneski.

Blowin's picture
Blowin's picture
Blowin commented Tuesday, 24 Nov 2020 at 3:55pm

Thanks Huey .

You’ve got to know when to hold ‘em
Know when to fold ‘em
Know when to surf and.....know when to paint the house

Appreciate the opportunity to get shit done.

dawnperiscope's picture
dawnperiscope's picture
dawnperiscope commented Tuesday, 24 Nov 2020 at 9:56pm

Hey Ben
There’s a long period SE swell (small) that’s been showing up in the models for the weekend and is showing as the dominant swell. For the last few days I’ve been trying to figure out where it originated but can’t work it out.
I’m not even surfing this weekend but it’s got me perplexed!

Ride on

thermalben's picture
thermalben's picture
thermalben commented Wednesday, 25 Nov 2020 at 6:55am

Which coast are you referring to? Just so I can check.

But, I'm glad you brought it up as there's a tiny distant pulse that had slipped under my radar. 

First off, Saturday has small easing mid period SE swell from what's expected to show Thurs/Fri. You can see it in the table below (Gold Coast), in red. 

But! Also on Saturday morning, a longer period (14.5 second forerunners) E/SE swell makes landfall, becoming the dominant swell into Sunday and peaking that afternoon around 0.6m at 12 seconds (I presume this is the one you're referring to? See green, below). This is the one I missed.

Usually, weekend swell sources will usually appear on our current spread of charts from about Tuesday or Wednesday onwards. I scanned the current WAMS and couldn't see anything at all (given the swell direction and period, likely north and east of New Zealand). So, further investigation was required.

In this case, the longer swell periods indicate a decent sized storm with very strong winds, so anything generated earlier than Tues/Wed means it must have originated much further away than our usual swell source regions.

So, I went back through the hindcast charts, and lo and behold - sitting right on the edge of our expansive South Pacific maps - was this impressive sub-tropical low, last Saturday. The low is well SE of Tahiti, with the main fetch around 7,300km from Australia. 

The irony here is that Craig wrote an article in 2014 Off the charts: The mystery of mysto swells, where he explained the inherent limitations of the BOM's spatially small synoptic charts, and detailed how much better our charts are, because they extend much further into the South Pacific.

But in this instance, not only did I not spot the potential swell source during my Mon/Wed/Fri notes (which should have been visible for at least four or five days leading up to last Saturday), but it was almost off the edge of our own charts!

Truth be told, storms this far from last have to be enormous to generate any meaningful surf for Australia. And, with the synoptics showing potential activity from much more local sources around the same time frame, there wasn't a great deal of point in detailing the specifics of far-flung low pressure systems - because ultimately their energy won't be visible anyway - only if there's a complete absence of swell sources by the time they make landfall (which, ironically may happen this Sunday, though the local N'ly flow will probably ruin conditions anyway).

Another fun fact - the bulk fetch on the chart above is E/SE (on the western half of the low's southern flank). But at this position, relative to our swell window, best exposure to the storm would actually require an E/NE fetch, which would be pointed straight at us across the Great Circle paths.

So, thanks DP - it's been fun tracing this hidden swell source. Just a shame it probably won't amount to much at the coast!

gunther's picture
gunther's picture
gunther commented Wednesday, 25 Nov 2020 at 8:16am

Great circle paths trip me out!

dawnperiscope's picture
dawnperiscope's picture
dawnperiscope commented Wednesday, 25 Nov 2020 at 2:33pm

Fascinating! Thanks for such a comprehensive analysis.
I first saw it on, he hem, seabreeze, on sunday as it showed up in the 7 day forecast as the dominant swell. It was (and still is out of interest) showing as SE in direction on that site so I was hunting around on the charts and didn't even think to look beyond NZ. I figured there was something afoot with the models (or that cook strait was predicted to widen in the next 7 days!)
I can now head off down to Sydney with the family for the weekend and my FOMO can rest easy.
Thanks again Ben.

Ride on

Rockethut's picture
Rockethut's picture
Rockethut commented Wednesday, 25 Nov 2020 at 8:18am

I'm holding thumbs the models are correct. It would be great to have a long period east swell resulting in 2-3ft surf over the next 4 days for SEQ.

freeride76's picture
freeride76's picture
freeride76 commented Wednesday, 25 Nov 2020 at 8:21am

that ain't gunna happen.

Rockethut's picture
Rockethut's picture
Rockethut commented Wednesday, 25 Nov 2020 at 10:13am

I'll accept 2ft with sporadic intermittent 3ft sets even at 20min wait time.

thermalben's picture
thermalben's picture
thermalben commented Wednesday, 25 Nov 2020 at 11:27am

Unfortunately, your request is denied. 

Rockethut's picture
Rockethut's picture
Rockethut commented Wednesday, 25 Nov 2020 at 10:31am

Actually I think the models suggesting the upcoming east swell is nothing more than that of the existing tazman low generating the below mentioned south swell. The models are relating this into a SE flow for SEQ.

"Open beaches should maintain 3ft sets across Northern NSW on Thursday though it’ll be smaller throughout SE Qld, with 2ft sets at exposed beaches and smaller waves again along the points, though the wavelength will have drawn out by then so surf quality should be a little better. "

thermalben's picture
thermalben's picture
thermalben commented Wednesday, 25 Nov 2020 at 11:29am

As per my detailed comment above, there are two individual swells.

The first - mid period energy from the SE - is from the Tasman Low (and was mentioned in my FC notes as per the sentence you quoted).

The second - longer period energy from the E/SE - is from the distant South Pacific sub tropical low, and wasn't mentioned in Monday's notes.

Rockethut's picture
Rockethut's picture
Rockethut commented Wednesday, 25 Nov 2020 at 12:27pm

Yip and these I reckon are what the graphs are possibly exaggerating on as compared to in that far distant east swell you spoke about in these notes.

Redmond Clement's picture
Redmond Clement's picture
Redmond Clement commented Wednesday, 25 Nov 2020 at 11:56am

Enlightening stuff. Love your optimism Rockethut.

Rockethut's picture
Rockethut's picture
Rockethut commented Wednesday, 25 Nov 2020 at 12:32pm

I feel like a heroin addict on day 4 of their cleanse! I need to surf

freeride76's picture
freeride76's picture
freeride76 commented Wednesday, 25 Nov 2020 at 2:33pm

what are you doing, it's fun as shitt today.

AndyM's picture
AndyM's picture
AndyM commented Wednesday, 25 Nov 2020 at 3:00pm

Some great waves today, I has some 3 foot point break waves by myself with no-one around, as in, not a single person.

There're benefits to people being fixated with marquee breaks.

freeride76's picture
freeride76's picture
freeride76 commented Wednesday, 25 Nov 2020 at 3:25pm

not even that many surfing the marquee breaks.

just a day that punched above it's weight.

surfiebum's picture
surfiebum's picture
surfiebum commented Wednesday, 25 Nov 2020 at 4:53pm

Meanwhile on the sunny coast.... *cries*

Rockethut's picture
Rockethut's picture
Rockethut commented Wednesday, 25 Nov 2020 at 5:39pm

Where was worth surfing today?
Asking for a friend...

I'm on the Gold Coast and here was shit.

Solitude's picture
Solitude's picture
Solitude commented Wednesday, 25 Nov 2020 at 7:44pm

Rock - yeah was thinking the same mate. Select spots around Leba I’d say

freeride76's picture
freeride76's picture
freeride76 commented Wednesday, 25 Nov 2020 at 7:55pm

2 fun sessions and a tailor off the rocks.

not a bad day for late Nov.

was 3-4ft for about an hour on the first hour of the incoming tide push.

pretty much all gone by late arvo.

Blowin's picture
Blowin's picture
Blowin commented Wednesday, 25 Nov 2020 at 8:10pm

Ha ! You blew it !

You shoulda been at Kempsey Bunnings . It was firing.

AndyM's picture
AndyM's picture
AndyM commented Wednesday, 25 Nov 2020 at 8:16pm

Now you’re just being a skite.
Yeah it’s a good life.
In other news, my new kayak just turned up, a Nymboida mission is definitely on the cards.

In the meantime, I’m gonna sit in front of this fire, watch the last of the colour fade from the sky and drink this frosty beer.