Plenty of swell, but dodgy winds galore

Ben Matson picture
Ben Matson (thermalben)

Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 19th January)

Best Days: No great days due to average local winds. But there'll be rideable surf for the entire period. Good E/NE groundswell over the weekend with possibly a few pockets of good winds.

Recap: Nothing amazing over the weekend. Small, easing south swell Saturday with tiny conditions early Sunday ahead of a small new south swell mid-late afternoon that was unfortunately accompanied by a fresh onshore breeze.

This week (Jan 20-24)

Nothing great is likely in the surf department over the next few days

If you were to pass a casual glance across the surfcams, you’d never know that there’s actually a decent south swell in the water right now with 3ft sets at Bondi. 

This swell originated from a strong frontal progression below Tasmania over the weekend. And it’s not over yet - we’re actually expecting a peak in size early Tuesday with 3ft to almost 4ft sets at south facing beaches (bigger in the Hunter) but smaller waves elsewhere.

Unfortunately, today’s S/SE winds are due to swing E’ly then NE over the next few days as a large Tasman high slides eastwards and an inland trough over the eastern states pushes against the high. So surface conditions will be rather bumpy and choppy.

In fact, this pattern is expected to remain slow moving for a few days - we’re looking at NE winds right through into the weekend. They’ll slacken off a little around Thursday or Friday in response to a weakening of the inland trough, but will still remain from this direction.

As for other swell sources, a broad ridge across the central/northern Tasman Sea will generate some small mid-range energy all week (same direction as the prevailing local winds). Nothing too large but enough to supplement the south swell, which will fade quickly from Wednesday. NE facing beaches should see (bumpy) 2-3ft sets on Wednesday with smaller surf expected through Thursday, along with a minor improvement on the surface as the wind eases a touch.

There are more interesting developments afoot though: over the next few days a broad Tropical Low in the Coral Sea is expected to track southwards, intensifying as it passes south of New Caledonia. In fact this system is expected to track into an excellent part of our swell window and will evatually produce a nice round of E/NE swell for the southern NSW coast.

Prior to its arrival, for the most part Thursday will see small peaky NE swell perhaps to 2ft+ at NE swell magnets. On Friday though, the first signs of new energy from this system should start to appear and should start to nudge the 3ft range through the afternoon (I’ll have a better idea of the timing on Wednesday), which should sit nicely with the pre-exiting NE windswell of 2ft+.

This weekend (Jan 25-26)

E/NE swell from the Coral Sea low should hold steady across much of the weekend. 

But unfortunately, despite this low tracking into one of my favourite swell windows for Southern NSW, there are a couple of downsides to this event.

Firstly, core wind speeds around the intensifying low won’t reach any great strength. So, this will keep a lid on swell periods and eventual surf size. Secondly, it looks like we’ll see persistent NE winds through much of the weekend, with the next southerly change not likely until Sunday afternoon (at the earliest). So, conditions may not be great (you’ll have to work around small pockets of lighter winds).

Also in the water on Saturday will be a continuing level of NE windswell in the water. At this stage, we’re likely to see (inconsistent) 3ft+ of quality E/NE groundswell and a smaller level of NE windswell. Expect average conditions with moderate to fresh NE winds (may be brief windows of lighter winds if we're lucky).

The gusty southerly change due later Sunday will also throw a few curveballs into the mix. We should see a continuation of E/NE groundswell (inconsistent 3ft+ sets at NE facing beaches) through Sunday morning, although an easing trend is likely during the day. And at this stage the early session should also have some small NE windswell in the mix, but the southerly change will dictate surf conditions - it’s plausible that winds will veer NW ahead of it (or at least variable) but we really need a few more days to tie down the particulars. However, I’m mildly optimistic that Sunday morning will offer something worthwhile.

Obviously, a local S’ly windswell in the wake of the change is also a possibility but again, a few more model runs will shed a stronger light on the timing of this.

Next week (Jan 27 onwards)

Monday looks to be dominated with whatever eventuates form Sunday’s late S’ly change. Which is most probably, a short range southerly swell and gusty but easing winds from the southern quadrant.

Otherwise, there’s nothing major on the synoptic charts for the long term although the Northern Tasman will remain active all weekend with a modest but somewhat stationary NE fetch, being the head of a broader trade flow across the South-western Pacific (north and north-east of New Zealand).

This suggests - as a minimum - some small persistent E/NE swell across open beaches for there foreseeable future. And hopefully the eventual breeding ground for a much bigger swell generating system too! Check back on Wednesday for more details.


Ralph's picture
Ralph's picture
Ralph Tuesday, 20 Jan 2015 at 9:22am

Gidday Ben. Do you anticipate that the size of the groundswell will be fairly uniform north and south of Sydney or do you expect that it will be stronger further north and weaker down south??

thermalben's picture
thermalben's picture
thermalben Wednesday, 21 Jan 2015 at 3:17pm

Sorry for the delayed reply, didn't see this comment. Should be fairly uniform up and down the coast. Good news too is that the models have strengthen both the local fetch and the Coral Sea low so we should see a little more size than noted in Monday's forecast.

Sheepdog's picture
Sheepdog's picture
Sheepdog Tuesday, 20 Jan 2015 at 9:50am

Flying up to Sydney tomorrow for 2 days, and of course it looks like shite.... Won't take the board... Just hit the restaurants.... At least it wont be cold....

geoffrey's picture
geoffrey's picture
geoffrey Wednesday, 21 Jan 2015 at 3:51pm

was solid 4 foot this arvo and really not any wind up until around an hour ago.

stunet's picture
stunet's picture
stunet Wednesday, 21 Jan 2015 at 3:58pm

Good surf on the Coal Coast around midday. Wind has come up a tad now. 3 to 4 foot sets where I surfed.

thermalben's picture
thermalben's picture
thermalben Wednesday, 21 Jan 2015 at 4:00pm

Yeah winds were surprisingly light all morning in most areas. I've detailed this in the updated notes here.