Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 21st January)

Best Days: Most days should have a mix of fun small swells. Tues for a S'ly swell, Wed for a NE windswell, Thurs/Fri for a mix of S'ly and E/SE swell, Sat for a NE windswell and Sun for an unusual long period S/SE groundswell. Winds are tricky but there'll be windows, mainly early mornings.

Recap: Saturday delivered early light winds and peaky NE windswells around 2-3ft. Southerly windswells built into the afternoon behind a mid-late morning change, and persisted around 2ft+ across most south facing beaches into Sunday as a secondary southerly groundswell pushed through. Isolated reports of larger 3ft+ waves have come through (on Sunday), though buoy data doesn’t suggest anything notable (these were certainly the exception rather than the rule). Winds were light and variable for much of the day so conditions were clean. Wave heights eased back to 1-2ft out of the south this morning - though slightly bigger across the Hunter - and winds have again remained light in most regions, except Newcastle which saw a brief period of moderate southerlies around dawn as a band of rain showers passed over the region. 

Fun afternoon peaky S'ly swell in Newcastle. Not bad considering the tiny surf in Sydney!

This week (Jan 22 - 25)

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The Tasman Sea won’t see a great deal of synoptic activity throughout the forecast period, so most of our swell sources will originate from more distant, flukey swell windows. 

The most prominent energy is a small, long period S’ly swell currently pushing up through the Tasmanian region, generated by a powerful front late last week and over the weekend. 

It was poorly aligned within our swell window, so the glancing energy will only favour south swell magnets, providing inconsistent 2-3ft sets through Tuesday and early Wednesday. We may see bigger sets nudging 3-4ft across the Hunter region at times. However beaches not open to the south will be much smaller, and wave heights will trend down through Wednesday so make the most of Tuesday for the most size. 

Fortunately, conditions will be clean with light variable winds Tuesday morning, ahead of a fresh NE sea breeze into the afternoon. 

A shallow southerly change will push slowly up the coast on Wednesday, arriving mid-late morning across the Illawarra coast but possibly not until early-mid afternoon north of Sydney. Prior to its arrival we’ll see freshening N/NE winds (outside chance for isolated patches of variable conditions).

Wednesday will also see some some peaky NE windswell in the water courtesy of Tuesday afternoon’s late freshening trend, with low quality sets just up to 2ft+ mark. 

The rest of the week will see a couple of tricky swell sources contribute waves to our region.

Wednesday’s shallow change will peter out into a broad trough, likely leaving us with light variable winds and sea breezes (though moderate to fresh E’ly winds are possible south from the Illawarra). E’ly winds along the southern flank of the trough should supply a peaky short range swell to the South Coast but it’ll be smaller north from the Illawarra. Let’s peg possible 2ft+ sets at open beaches if we’re lucky.

A more favourably aligned front will push into the southern Tasman overnight Tuesday and into Wednesday, underneath the developing trough, generating a brief flush of S’ly swell up to 2-3ft at south swell magnets on Thursday. This swell will ease through Friday.

And lastly, the parent Southern Ocean low to the fronts that generated Tuesday’s swells is lingering well south-east of New Zealand at the moment, and two interesting fetches will generate small long period S/SE swell for Southern NSW later this week and into the weekend. The main fetch is poorly aligned, but stationary - so we’ll see a minor spread back into the coast around Friday, though I doubt we'll see much more than an inconsistent 2ft set at south facing beaches. The second swell will arrive over the weekend and is detailed below.

Friday’s winds will pick up from the NE throughout the day (building local NE windswells into the afternoon), but they’ll be lighter earlier with a window of cleaner conditions.

As such, Thursday looks like the best window for the second half of the weekend. 

This weekend (Jan 26 - 27)

We’ve got some interesting swell ahead for the weekend, but ultimately you’ll need to exercise some caution if you're planning any highway miles.

Strengthening NE winds Friday night should kick up 2-3ft peaky NE swell for Saturday. A shallow trough will push up the coast, resulting in the development of light winds across most regions throughout the morning (delayed in the Hunter), but the source fetch may linger off the Mid North Coast so we’re likely to see short range NE energy persist into Sunday. 

Whilst this is going on, a small long period S/SE swell will be advancing along the coast, generated by a small secondary polar low strengthening well south of New Zealand from Tuesday through Wednesday. The models are throwing up some interesting numbers for this event - estimating a leading edge of 0.4m at 15.8 seconds out of the S/SE (in Sydney) around midnight Saturday, building to 0.8m by 6pm Sunday as the swell period eases to 13.8 seconds. Obviously, we’ll see an arrival much earlier across the South Coast, possibly around lunchtime. 

These numbers would suggest solid 4ft surf across exposed south facing beaches (on Sunday) but I’m a little cautious given the distant swell source, and the erratic nature of any fetch sitting close to (if not on top of) the ice shelf. The models also usually undercall swells from this region, which further reduces my confidence. 

I do like the sustained nature of this system, so I think we’ll see good surf prospects from it, if somewhat inconsistent at times - and with redeveloping northerly winds you’ll have to hunt down an appropriate south swell magnets offering protection. I’ll peg wave heights up around the 3ft mark at this stage - with long breaks between waves - and wait to see how our mid-week satellite data comes back.

Next week (Jan 28 onwards)

The Southern Ocean storm track doesn’t look great for our region next week, and the Tasman Sea will remain devoid of activity. 

However we are looking at resurgence of activity across the top end (Far Northern Qld) next week, in the form of a tropical low or cyclone. Whilst this doesn’t point to a specific swell event, it does suggest we’ll see an infeed of tropical moisture towards southern regions, which is one of several required ingredients for the development of any significant kind of weather system in the Tasman Sea. 

In short: the end of January and early February are shaping up to be a little more on the dynamic side for swell prospects, compared to the last few weeks.

More on this in Wednesday’s update.