Saturday has the best conditions, tricky winds otherwise

Ben Matson picture
Ben Matson (thermalben)

Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Friday 1st April)

Best Days: No great days overall, but Sat should have small clean south swell at swell magnets. Somewhat wind affected surf for the most part every other day. Good potential for the long term though.

Recap: Building short range S’ly swell on Thursday reaching 4ft at south facing beaches. Easing S’ly swell from today with sets still around 3ft at south facing beaches. 


Still some sets at Bondi this afternoon

This weekend (Saturday 2nd - Sunday 3rd):

*Minor caveat for today’s notes: I’m jumping in fresh as Guy is away today, and having not looked at Sydney charts for some time, my confidence isn’t as high as it should ordinarily be.

In short: Saturday is your best day for waves. Overnight northerly winds will swing north-west in the morning, then westerly through the day as a front approaches from the south-west. Strong southerly winds associated with the change are expected across the Far South Coast later Saturday and should reach Sydney overnight, persisting throughout much of Sunday as the direction swings more to the south-east., thanks to the change stalling as it moves up the coast. 

So Sunday looks very ordinary on the surface, but Saturday should be nice and clean - perhaps a little early northerly wobble but it’ll clean up as the day wears on.

As for surf, the current S’ly swell is expected to fade into Saturday however a new long range southerly swell is forecast to push up the coast later today and provide very inconsistent waves to south facing beaches. This is the same swell that graced the Victorian coast today, providing excellent waves at Bells Beach for the Rip Curl Pro.

However, I am a little skeptical that this swell will produce much size for Southern NSW -  the source of the swell was a considerable distance from the mainland, and its alignment wasn’t especially favourable for the Tasman Sea (specifically, the East Coast) either.

On the other hand, we have seen a number of southerly groundswells produce bigger waves than expected in recent weeks, from similarly located weather systems. So it’d be foolish to write off this weekend’s prospects of some decent energy out of the south. 

Model guidance really doesn’t like Saturday’s groundswell at all - it’s barely registering anything, well under half a metre from the south at 11-12 seconds (where as the Cape Sorell buoy off Tasmania’s West Coast pick up the leading edge at 18.5 seconds late yesterday). Our surf model consequently has almost no size from the south, however I think we’ll see more than this - I’m going to split the difference from Wednesday’s forecast notes and expect very inconsistent 1-2ft+ waves at the region’s more reliable south facing beaches (especially Newcastle, which may be a shade bigger). However beaches not open to the south will be much, much smaller. 

As for Sunday, we’ll have a combination of S’ly groundswell (including a minor new pulse of similar long range energy as per Saturday, though a tad smaller) plus a building S’ly windswell, the latter of which should reach 3ft at south facing beaches thorough the afternoon. If your only option to surf is on Sunday, then perhaps leave it until the afternoon as the onshore airstream may ease a touch by then. But on the balance it’s looking pretty bumpy and messy.

Next week (Monday 4th onward)

No major swells expected for next week though there is plenty of potential on the cards. 

Sunday’s onshore airstream will ease rapidly into Monday, providing small bumpy waves at open beaches in and around the 1-2ft range as winds linger for the east, tending north-east later.

We should also see a couple of pulses of southerly swell - yet another distant long period energy (same swells as we’re expecting for the Rip Curl Pro this weekend), but also some refracted S’ly swell from the parent low to Sunday’s change, as it passes south of Tasmania on Saturday night. This should kick up occasion 2-3ft sets at south facing beaches but for the most part, this swell will bypass the majority of Southern NSW - aim for your most reliable south swell magnet. Most other beaches will be quite a bit smaller.

An approaching front will freshen northerly winds from Tuesday into Wednesday, generating some local short period NE windswell that may possibly reach a peak Wednesday around the 2ft+ mark at exposed NE facing beaches, whilst Monday's south swell eases.

A southerly change trailing the front should kick up 3ft+ of southerly swell for Thursday but there’s a reasonable chance exposed locations will be wind affected. 

Looking to our north, and we have some interesting tropical developments out near Fiji however this broad system - whilst it looks impressive as individual synoptic snapshots - is expected to migrate eastwards, which significantly affects its swell potential. So don’t get too excited right now.

Otherwise, it looks like we’ll be heading into a classic autumn period of back-to-back Southern Ocean fronts across the Tasmanian region, delivering multiple southerly groundswells through the latter part of next week, the weekend and the first half of the following week. I’m expecting that one of two of these swells could become quite sizeable at south facing beaches. But Guy will have more on that next week.

Comments

thermalben's picture
thermalben's picture
thermalben Friday, 1 Apr 2016 at 5:44pm

Late arvo party wave (useful for size reference, anyway).

black-duck's picture
black-duck's picture
black-duck Friday, 1 Apr 2016 at 11:52pm

Hey Ben. I would guess a lot of guys that look at this site do their own thumb nail predictions for surf, with a cross check with Swellnet or other sites for verification or validation with other charts. I have noticed of late how the Swellnet puta model forecast has been way out of whack with the forecast notes. Like way out. Generally big under calls of late on the puta models in comparison to reality. Winds have been out as well, which is understandable. Talking south coast only here. Wouldn't dare venture into the north coast frenzy that generates pages of hyped forecast analysis. For mine, the sth coast stuff has reached a point where i rarely look at the Swellnet forecast charts anymore due to their inaccuracy, as the detailed forecast notes are more often than not way more on the ball. It's a thing and I'm sure your own hind casts would tell the same story? I understand the complexity and difficulty of puta modelling but have been surprised at the models of late and their interpretation of what seem to be some fairly obvious synoptic patterns that the forecast notes from Guy, or others, prove otherwise. Also occasionally delighted at the forecast notes predictions of reasonable swell that i don't see on the charts that lead to fruition.
What's happening with the models?

thermalben's picture
thermalben's picture
thermalben Saturday, 2 Apr 2016 at 7:43am

Yeah, it's very strange. Unfortunately, we have no real way of altering the initial model data (WaveWatch III, which we run in-house) so the only way to rectify these problems is to speak directly with NOAA and ask them to investigate (which we've done a couple of times over the last ten years). It's unlikely that a solution can be found in the near future.

For what it's worth, all other surf forecast websites using model data for their forecasts are seeing similar problems, so we know it's the WW3 model causing this, and nothing at our end. Magic Seaweed has 1-2ft surf at Bondi (remember, that's face feet too - so knee high) with their model data just 1.7ft @ 7 seconds. Surfline also have 1-2ft for Bondi (again, face feet, so knee high). So this is exactly the same as our 1ft forecast. 

So in short, when the WW3 model is bang on, our forecasts are spot on (as we're confident we have nailed our swell-to-surf conversions) but as soon as WW3 has a problem, the whole house falls down.

Chris Buykx's picture
Chris Buykx's picture
Chris Buykx Sunday, 3 Apr 2016 at 7:52am

Saturday we were enjoying solid 3'+ long period sets (around 16 sec) groomed to perfection under nice offshores. For the last 2 weeks the models have way undervalued these long period, long range swells. As Guy has pointed out a few times in the notes, some of these swells are coming around the corner from way out on the edge of our swell window. Yesterdays was from behind Tassie, last weeks was from behind North island. Perhaps the models are not properly resolving the ability of these ground swells to wrap on to the East coast.
Regardless, how good has this summer been? We have had almost non stop groundswells in 12-16 second range since December. Has hardly been any NE windswell days.

Craig's picture
Craig's picture
Craig Sunday, 3 Apr 2016 at 8:47am

Best start to the year I've seen. Surfed effectively every day and not below 2ft!

Dried up a little now.

stunet's picture
stunet's picture
stunet Monday, 4 Apr 2016 at 10:31am

RE the NE winds:

Last summer - i.e 2014/15 - I recall there being less NE winds than usual. I don't have any records, it's purely anecdotal, but I recall a scarcity of sea breezes. I made a mental note at the time.

When I was younger I remember reading that Sydney gets approx. 22 days a month NE wind during summer. That felt about right. Yet last year, and even more so this year, that number is way down. Going on my gut, during the summer just gone I'd say the NE days would be about half that.

Wonder if anyone is paying attention to this in a formal way?

geoffrey's picture
geoffrey's picture
geoffrey Sunday, 3 Apr 2016 at 3:30pm

Hey ben, reckon there will be a light offshore or light onshore flow down south between Ulladulla and Nowra tomorrow? The models I check are split 50 50 between the two.

geoffrey's picture
geoffrey's picture
geoffrey Sunday, 3 Apr 2016 at 3:31pm

Tomorrow morning to be precise

Chris Buykx's picture
Chris Buykx's picture
Chris Buykx Monday, 4 Apr 2016 at 11:48am

The constant long period swell has also done interesting things to the banks, unlike what we have seen in summers past. Usually low energy windswells and bigger tides create a "Low Tide terrace" sandbank - which are usually short sharp and featureless.
This summer we have a higher energy "Rhythmic Bar and Beach" set up at my local. The rips have been in almost permanent location and the banks have varied, but been typically really quick and hollow.
We had a comp on Saturday and one of the Hazza's (think it was Sean) got soo barrelled on the low tide it was seriously looking like the super bank!
Might have to write a Coastal Creationism on how beaches respond to increasing and decreasing wave energy!