Sydney Hunter Illawarra Surf Forecast by Ben Matson (issued Mon Dec 18)

Features of the Forecast (tl;dr)

• Small NE swell for Tues PM, prob light winds too
• Messy S/SE swell Wed/Thurs with accompanying S'ly winds
• Easing S/SE swell Fri with improving conditions as winds ease and swing SW, plus a building E/NE swell
• Great weekend of waves with generally light winds, and a peak in E/NE swell plus some easing S/SE swell Sat
• Lotta potential for next week too

Recap

The weekend saw very little surf, with minor southerly swells both days and moderate onshore winds making a mess of things on Sunday morning. Today has seen better surf with an uptick in E'ly swell slightly bigger than expected (preaky 2-3ft sets), and favourable conditions with light winds. The surf is a little on the slow side though.

Fun small peaks at Maroubra today

This week (Dec 19 - 22)

(thanks belly for the title!)

Lots of synoptic activity on the cards this week but ultimately just a few small windows of opportunity until the weekend when we'll see the dynamics change. 

A trough will push up the Southern NSW coast on Tuesday, reaching the Far South Coast after lunch and the Illawarra late afternoon (and thus the Sydney region after dark).

Freshening N/NE winds feeding into the trough will probably remain light to moderate across the coastal margin, and may even become variable for periods of times - however they will be quite strong well off the Mid North Coast and this will build NE swells across our region through the day. 

However the fetch alignment isn't quite as good as what was anticipated in Friday's model runs so I am going to peg back my expectations (both size and timing). We'll see surf size build into the afternoon (small leftover E'ly swell early morning), with the late afternoon likely to reach 2ft at most open beaches, perhaps a few 2-3ft sets at NE swell magnets (I'm less confident on this swell showing well south of the Illawarra, due to the short fetch length and timing). 

So, aim for a late surf at the open beaches and you should do OK.

Fresh southerly winds will then envelop the coast on Wednesday, building low quality surf at exposed beaches, possibly some 3-4ft sets into the afternoon, but it won't be anything to get excited about. The NE swell will be gone by this time. Southern ends will be small and average, I reckon.

During this time, the coastal trough will remain anchored in a position off the Mid North Coast, and it may evolve into a small Tasman Low by Thursday, which will only enhance wind strengths on its western flank, aimed into Southern NSW. Unfortunately, its close proximity means surf quality won't be great under the dominant southerly flow, though Thursday's extra size - maybe somewhere between 4ft to 6ft at south facing beaches - means we should start to see worthwhile options at protected southern ends. 

The low will disipate into Friday and retreat to the south, which means easing local winds and wave heights to finish the working week. We should start to see pockets of favourable SW winds through the dat too, though exposed stretches will remain wobbly.

But.. that won't be the only swell in the water.

Throughout the week, whilst this complex trough meanders along the NSW coast, an E'ly dip is expected to form near New Caledonia (Tues/Wed), at the head of a broadening ridge currently building trade swells for the East Coast.

This E'ly dip will then travel southwards, building E/NE swells that are expected to arrive on Friday (2-3ft) towards a peak on Saturday (3-4ft). 

As such, Friday has plenty of potential with a mix of easing S/SE and building E/NE swell along with an abating southerly breeze that should back to the SW in some regions.

This weekend (23 - 24)

We've got a great weelend of surf ahead.

The small Tasman Low should be well and truly gone by Saturday, allowing light variable winds to prevail both days under a weak synoptic gradient.

The aforementioned E/NE swell should build to a peak in size on Saturday with 3-4ft sets at most beaches, before slowly easing through Sunday.

Saturday should also see some leftover S/SE swell from the latter stages of the SE fetch around the bottom of the Tasman Low (on Friday) though we'll see the most size from this on the Far South Coast (3-4ft), with 2-3ft surf north from the Illawarra.

All in all, a very nice way to kick off the summer holidays!

Next week (Dec 25 onwards)

Coastal troughs will dominate next week too, meaning we'll have a wide range of local swell sources kicking up a variety of surf conditions. There's nothig we can pin down specifricaly at this stage, but either way it's looking very positive for the last week of 2023.

See you Wednesday!