Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Wednesday 13th January)

Features of the Forecast (tl;dr)

• Small mix of swells Thurs/Fri, though wind affected at times on Thurs
• Fun S'ly swell for Sat (wind affected at first)
• Stronger S'ly groundswell building Sun, holding Mon
• Large S'ly swell building Tues, peaking Wed, easing slowly Thurs onwards

Recap: Small peaky NE swells built from 1-1.5ft on Tuesday morning to a more consistent 2ft this morning. Conditions have been clean early with light winds but the afternoons have seen freshening breezes from the NE. 

Small NE windswells this morning

This week (Jan 14 - 15)

A weak trough will push up the Southern NSW coast on Thursday, gradually swinging winds to the south. However, most Sydney, Hunter and Illawarra beaches will see freshening N/NE winds ahead of the change, with an arrival due into the South Coast just before lunch, the Illawarra mid-late afternoon and then Sydney in the early evening.

These local N/NE winds will slightly increase the size of the local N/NE windswell during the day, though 2-3ft sets will be rare across most open beaches into the afternoon, so in general expect smaller waves (though the South Coast should see a little more size, due to the longer fetch length).

There’ll be a small undercurrent of trade swell in the water too. Winds should be light early morning, north from Sydney. Keep your expectations low. 

As a side note, southerly winds will develop early Thursday off the Far South Coast so a building S’ly windswell is likely across locations south from the Illawarra into the afternoon, though this energy will be accompanied with breezey conditions.

In general, we’re only expecting a small trailing fetch behind the trough so no major size is expected on Friday, just a peaky mix of small S and residual E/NE and NE swells, with 2ft sets at exposed beaches. The good news is that the trough will weak so conditions will become clean with light variable winds ahead of an afternoon NE sea breeze. 

This weekend (Jan 16 - 17)

A vigorous front will push into the Tasman Sea overnight Friday, with temporary southerly gales developing parallel to the Southern NSW coast. 

However, winds will quickly ease thanks to a brief ridge filling behind, prior to a stronger front racing up into the lower Tasman Sea during the day. 

The first front will generate short lived southerly windswells, but the second front will have a broader, stronger fetch - though less favourable aligned within our swell window. And, this second front is not expected to impact Sydney, Hunter and Illawarra coasts to the same degree either, so conditions should be good for the second half of the weekend. 

Therefore, it’s looking like a weekend of two halves, with initially wind affected, building S’ly windswells on Saturday morning - improving into the afternoon as the wind throttles back quickly - with size reaching 3-4ft at south facing beaches. It’ll be much smaller at beaches not open to the south. We may also see an easing size trend through the afternoon. 

Sunday’s new S’ly groundswell will build slowly during the day, following an initial decrease (from Saturday) early morning around 2-3ft at south facing beaches, back up to 4-5ft by late afternoon. We’ll see bigger sets across the Hunter though it’ll be much smaller at beaches not open to the south.

Next week (Jan 18 onwards)

As mentioned on Monday, we’ve got a strong southerly swell cycle on the boil. The weekend will see the early (small) stages of this pattern but the real juice is lining up for the first half of next week. 

The only concern I have at this stage is that the storm track will be right on the periphery of the Tasmanian swell shadow. If it shifts a fraction to the west, we’ll see size projections halve (if not more). Conversely, a slight eastward shift may open up even larger size prospects.

For now, Monday is looking at steady size holding 4-5ft at south facing beaches (bigger in the Hunter, smaller elsewhere) following on from Sunday’s late building trend. Clean morning conditions will precede freshening NE breezes through the afternoon.

The main system from this sequence - an intensifying polar low, being slingshotted to the north around an amplifying node of the Long Wave Trough (see below) - is expected to generate a very large swell that’ll build throughout Tuesday and then peak on Wednesday, with 6-8ft+ sets at south facing beaches. Unfortunately, it does look like there will be quite a bit of southerly wind associated with this event - as is often the case with strong long wave patterns. But there won't be any shortage of size.

The long term trend beyond this maintains the slow moving nature of the LWT through the Tasman Sea, so any easing from Thursday through Friday will be gradual, rather than rapid. But, this is when the best surface conditions will occur as a high pressure system moves in from the west, creating clean conditions. 

So, a return to spring surf is ahead - hopefully your local is primed for solid, punchy, sizeable south swells. Because we’ve got quite a few days coming up that’ll tick that box nicely. 

See you Friday!