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

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Best Days: Tues AM: chance for an early window of leftover S'ly swell and temporarily lighter N'ly winds. Thurs: early light winds and a fun mix of S'ly and E/NE swell. Fri: early light winds and a fun E/NE swell (and some small leftover S'ly swell). Xmas Eve/Xmas Day: fun E/NE swell, aim for an early surf whilst winds are lighter.

Recap: A fun mix of NE and S swells on Saturday were accompanied by offshore winds, creating clean conditions for much of the day. Gusty S’ly winds filled in on Sunday, building a solid short range swell across the coast. This swell initially eased early this morning, supplemented by a secondary S’ly groundswell boosting wave heights to 3-4ft at south facing beaches through the middle of the day, and winds were light and variable this morning before moderate NE winds kicked in this afternoon.

This week (Dec 20th - 23rd)

There are no major swells on the way for the forecast period, so we’re relying on pre-existing swell energy and a couple of sources of small new swell.

First up - model guidance is holding today’s new S’ly swell in at 3-4ft for Tuesday morning. This was discussed as a possible anomaly in Friday’s notes (though at the time the model had less size for the same period, consequently resulting in a smaller projected surf size), with the new energy originating from the backside of the parent low that intensified well SE of Tasmania over the weekend. 

Reviewing the weekend’s satellite data shows that the primary fetch was aimed well away from our region, so I’m inclined to hold steady with my expectation for inconsistent 2-3ft sets at south facing beaches (bigger in the Hunter), which is a little smaller than our computer generated forecast is suggesting. However it’s a little unnerving to go against the model guidance during an extended swell event, when it’s been pretty much spot on over the last few days. 

Winds will be up from the N/NE throughout Tuesday anyway so you’ll have to aim for the morning session for the most size and best conditions; there’s a chance for a few localised regions of lighter N/NW winds but in general it’s expected to become quite fresh and gusty. Northern corners wil be your best friend.

We should also see a building NE windswell throughout the day, from 1-2ft up to 2-3ft at NE facing beaches and likely some bigger sets across the South Coast owing to the longer fetch length.

Also on Tuesday we’ll start to see the first few signs of a new E/NE groundswell from a tropical depression that’s occupied the Fijian region for quite some time now. Surf size will only be small to begin with, but the system is extremely slow moving and will remain in our swell window for a couple of days. In fact it’s expected to reach maturity around Wednesday or Thursday, which means we’ll probably see a peak in size around Saturday or Sunday - though it won’t be terribly large (occasional 3ft sets at exposed beaches). Prior to then expect an extremely slow upwards trend from Tuesday thru’ Friday.

A shallow S’ly change on Wednesday won’t deliver much in the way of new swell - and moderate southerly winds will confine the only clean options to southern ends - but the parent low/front to the south will kick up a better S’ly groundswell for Thursday with 3ft sets at south facing beaches, and bigger waves in the Hunter. The front responsible for the swell won’t be very well aligned but it’ll focus a decent fetch through the Southern Tasman Sea and should consequently deliver a good spread of fresh energy. Winds should be light and variable with sea breezes. 

Thursday’s south swell will then ease into Friday, with the E/NE swell becoming the dominant energy under an early light airstream ahead of a freshening nor’easter.

This weekend (Dec 24th - 25th)

The weekend - and indeed Xmas - forecast looks pretty uniform at the moment. The aforementioned E/NE groundswell should reach a broad plateau with inconsistent 3ft sets at most beaches both days. 

Conditions won’t be great, thanks to a Tasman high directing NE winds across the region both days too. We may see early periods of lighter N’ly winds but on the whole conditions will be cleanest at protected northern ends. There should be a small signal of short range NE swell in the mix too.

Next week (Dec 26th onwards)

Early indications are for a slowly easing E/NE groundswell and a continuation of NE winds and associated short range NE windswell on Monday. Our south swell window is expected to remain inactive for a little while but (at least in my opinion) I prefer to see the synoptics lighting up towards the east and north-east anyway.

So, pretty much a bog standard run of summer swell and winds ahead!

See you Wednesday.