thermalben

Peripheral vision all week

Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 12th October)

Best Days: Wed/Thurs: early light winds and a small mix of flukey south swells, plus some minor E/NE swell. Fri: light AM winds and a small peaky mix of swells, mainly E/NE. Sat/Sun: fun, small/mod S'ly groundswell, though inconsistent. Tricky winds. 

Recap: E/NE swells eased quickly through the weekend, with occasional 1-2ft sets on Saturday morning becoming smaller into the afternoon. A small pulse of S’ly swell glanced the region during the day and persisted into Sunday morning, though it didn’t crack much more than 2ft+ across the Hunter. Light winds and sea breezes were on display both days. Today has seen small residual swells from the south and east, still maintaining occasional 2ft sets across the Hunter though it’s smaller elsewhere. Winds have been mainly light to moderate from the S/SE.

Fun small Monday arvo sets in Newy

This week (Oct 13 - 16)

Small surf is still expected to be the dominant feature all week.

A generally slack pressure pattern across the Tasman Sea will maintain variable winds throughout Southern NSW each day; Thursday looks to be at the risk of the most strength in the breeze (and even then it won’t be especially strong). A weak front will clip the South Coast later Tuesday but the associated S'ly change will peter out across Sydney overnight and into the early hours of Wednesday morning. 

We’ve actually got quite a few swell sources, but they’re either weak or located on the periphery of our swell window, so there won’t be much size on offer at most beaches. 

First up, a ridge north and north-east of New Zealand will maintain minor E/NE swells across our region all week.

Secondly, a small ridge developing in the northern Tasman Sea today is aimed into SE Qld but we’ll see a small spread of E/NE swell across Southern NSW as the week progresses.

Thirdly, a modest front tracking under Tasmania today will generate a small south swell for Wed/Thurs, and an associated ridge pushing into the lower Tasman Sea tomorrow will generate a minor mid-week SE swell, perhaps offering 2ft to maybe 2-3ft sets into Thursday as well (about the same size as the underlying S’ly swell). 

The fourth swell source is the most interesting but the most flukey of them all. A series of powerful Southern Ocean lows under the continent over the last few days have generated long period groundswells, the leading edge of which is nosing into Victorian waters as we speak. This first swell is too west to efficiently bend around Tasmania, but the second swell - due into Victorian waters tomorrow - is slightly better positioned within our acute south swell window, and may just glance Southern NSW coasts later Wednesday and into Thursday.

With two pre-existing southerly and south-easterly swells in the water, it’s not worth worrying too much about specifics, as wave heights from this source will probably be about the same size (though a heck of a lot less consistent) - and as always with long period S’ly swells, the Hunter may pick up a few stray bigger sets. Nevertheless, any long-lined energy you see through this time frame will be likely attributable to this source. 

Funnily enough, our surf model is predicting Friday will see the largest waves of the working week (not true!), though the reality is by this time the three S/SE quadrant swells will be on the way back down and we’ll be relying on residual E/NE energy to keep the open beaches active.

So, keep your expectations low all week. Aim for Wednesday and Thursday mornings at your favourite south facing beach if you’re keen for a paddle. 

This weekend (Oct 17 - 18)

Another similar frontal passage to the one passing below Tasmania today is expected to occur on Thursday (see below), but at most lower latitudes. This should give rise to a similar S’ly and SE swell combo for Saturday and Sunday as we're expecting Wed/Thurs. 

I actually like the look of this system a lot better (stronger front, slight E/NE projection through a good part of our far south swell window) so although being extremely inconsistent thanks to the large travel distance, we stand a better chance of picking up 2-3ft sets at south facing beaches, maybe pushing 3-4ft+ in the Hunter.

Late Sunday may also herald the arrival of a very small long period E/NE swell from a tropical low developing south of Tahiti at the moment. It's an enormous distance from the mainland and the fetch length isn't amazing, but we may pick up a couple of feet of slow surf. 

Local winds look OK all weekend under the influence of a local trough - there is a northerly risk on Saturday, which may switch to the south later Sunday as the trough pushes off the coast, but there should be variable patches between. 

I’ll firm up the details a little better on Wednesday.

Next week (Oct 19 onwards)

An interesting tropical depression is standing out in the weekend’s synoptics near Fiji. At this stage it’s got enough potential to be considered an E/NE groundswell source for the early to middle part of next week. I’ll have a closer look on Wednesday (note: this is in addition to the earlier E/NE swell mentioned above, which should hold through Sunday afternoon into Monday).

Otherwise, lingering instability through the Tasman Sea next week certainly holds promise for a more locally based swell generating system, though it’s too early for specifics.

See you Wednesday!

Comments

brownie48's picture
brownie48's picture
brownie48 commented Monday, 12 Oct 2020 at 4:19pm

Wednesday looks like full on southerly onshores ?

Any chance of south swell for Tuesday, I cant see anything but always hopeful and it looks like its easterly only?

thermalben's picture
thermalben's picture
thermalben commented Monday, 12 Oct 2020 at 4:27pm

Just clarified the S'ly change for the South Coast later Tues; I think it'll abate quickly into Wed AM across Hunter/Sydney/Illawarra coasts. 

belly's picture
belly's picture
belly commented Wednesday, 14 Oct 2020 at 8:53am

2ft down south with the odd bigger one. Mostly short range south swell but seemed the odd straighter one as well.