Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Friday 12th January)

Best Days: Sat: peaky mix of NE and SE swells, good winds through mid-late morning. Mon/Tues: plenty of building south swell, periods of OK winds early morning. Wed: large S/SE tending SE swell building into the a'noon. Developing NE winds may spoil conditions. Thurs: generally good winds, large though steadily easing SE swell. 

Recap: Thursday saw very little surf across the Sydney coast, however a building SE swell has produced 2-3ft waves across south facing beaches today (after a small start at dawn), with slightly larger waves across the Hunter. Winds were light and variable early but are now freshening from the NE.  

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This weekend (Jan 13th - 14th)

We’ve got some nice waves on offer for Saturday.

I’m actually expecting today’s building SE swell to reach a peak overnight or perhaps early Saturday morning, thanks to a slightly better development than modelled through Wed/Thurs. We’re probably looking at inconsistent 2-3ft sets at south facing beaches, however the Hunter region should see a little more size as the fetch was better aimed towards Northern NSW.

At the same time, we’ll also see a peaky NE swell generated by overnight NE winds that are just starting to perk up now. Most NE facing beaches should see 2-3ft sets, though this source will be smaller at south facing beaches and across the Northern Hunter. 

Conditions are looking pretty good for the most part. An approaching S’ly change is due into the Sydney region mid-afternoon (earlier on the South Coast) and prior to it’s arrival we’ll see the overnight NE flow tend N’ly just before dawn, then slowly NW, W and SW through the middle of the day, whilst gradually freshening. 

As such, conditions may be a little wobbly early on but should improve rapidly. Mid-late morning is probably the best time to surf; a drop in NE swell is expected into the afternoon, especially once the S’ly change hits. 

The initial fetch trailing the S’ly change won’t be very strong, but a small new low pressure cell will form off the South Coast, and drive S/SW tending S’ly gales across the region from Sunday morning. 

This will in turn generate windy, relatively low quality S’ly swells throughout the day - south facing beaches will see plenty of size (4-5ft+ by the afternoon) but it’ll be very choppy. Beaches not facing due south will be much smaller but the option in these winds, save a brief period of early SW winds around dawn.

So, aim for Saturday over Sunday as it’ll offer a fun mix of peaky swells with a decent length of favourable winds. 

Next week (Jan 15th onwards)

Next week’s looking very complex. As discussed on Wednesday, we have a deep Tasman Low expected to develop though the specifics have moved around a little.

In fact, we’re looking at around five or six individual swell sources all related to the same broader parent system. As such it’s hard to pin down the precise trends as we’ll see many overlapping swell trains throughout the course of the week.

Also, it needs to be pointed out that we’ve seen some major fluctuations in model guidance over the last few days (indeed, since Monday). Yesterday alone saw a significant upgrade with our models calling 10-12ft surf at south facing beaches for Tues/Wed, however they halved overnight and are now estimating 5-6ft surf. This highlights how volatile the forecast period is and the difficulty in pinning down specifics at an early stage.

So, let’s take a look to see how things appear at the moment. 

Right now Monday is likely to see a drop from Sunday afternoon’s peak in windswell, perhaps down to 3-4ft at south facing beaches. We’ll already have a curveball in the mix by this time too from an unrelated system, in the form of a long period S’ly swell generated by a poorly positioned, SE-tracking Southern Ocean S/SW of Tasmania today (heading towards the Ice Shelf). Our model is picking up 0.4m @ 14 seconds from this source late afternoon (which wouldn’t come in higher than the above estimate) but I have a feeling it’ll be bigger than this with larger periods - probably still just up to the current threshold. But worth flagging anyway in case swell periods exceed that of the model guidance, then we’ll know where it came from.

Winds look workable though not great on Monday, mainly moderate S/SW but we should see a few regions display early SW or even W/SW winds early morning.

From Saturday onwards, a sharp trough will remain near-stationary across the central/eastern Tasman Sea, with intermittent southertly fetches across the western Tasman generating various short range swells for Sunday and Monday (as mentioned above). However a strong Southern Ocean front will enter the lower Tasman Sea on Monday afternoon, and considerably strengthen the overall flow, leading to a strong S’ly swell on Tuesday with 5-6ft+ sets at south facing beaches and smaller surf elsewhere.

Winds will become quite fresh from the south throughout the day, possibly SW for a brief period early morning at a handful of beaches (less than Monday morning). 

As this front pushes north-east, a deep Tasman Low will form along the trough line in the central/southern Tasman Sea. This system looks incredible on paper with a broad fetch of 40-50kt+ winds, however they’ll be aligned generally away from our swell window, so the energy we see at the coast will be smaller and less consistent than that of a coastline directly in the firing line. 

Wednesday will probably see a drop in size from the south throughout the morning, before this new S/SE energy pushes through from about lunchtime onwards (give or take). I’m going to increase the size expectations from Monday's notes, somewhere in the 6ft to maybe 6-8ft range at south facing beaches by late in the day with early light winds tending moderate to fresh NE into the afternoon. 

So, let’s hope the swell kicks in early as surface conditions will decrease after lunch with only a few rideable options across Southern NSW. 

This swell will ease steadily throughout Thursday, though early morning should still be a comparable size to late Wednesday. Winds should be generally OK, light out of the NW in the morning, though it’ll be a little flukey at times under a coastal troughy pattern. As such, Thursday morning is currently the pick of the forecast period for me.

Looking further ahead and a series of transitory mid-latitude cut-off lows south of Tasmania will provide more S’ly swell into the longer term period (next weekend and early in the following week), though nothing along the lines of what’s expected mid-next week. 

Have a great weekend, see you Monday!