Strong south swells - several of 'em - on the way

Ben Matson picture
Ben Matson (thermalben)

Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Wednesday 6th August)

Best Days: Thurs/Fri AM: fun leftover south swell with good winds in the morning. Very late Fri/Sat: excellent, large long period S'ly tending S/SE swell with good winds. Sun: easing S/SE swell with good winds. Tues/Wed: another strong S'ly swell.

Recap: The last two days have played out pretty much as expected. Tuesday morning saw small residual swell in the 2ft range ahead of a late afternoon arrival of new south swell that cracked the 3ft mark at exposed south facing beaches. Most exposed spots held in around this size this morning, however a slightly larger, longer period (Tp 19sec at the Sydney buoy) south swell filled in after lunch, with south facing beaches in Sydney seeing solid 3-4ft sets this afternoon, and the Hunter region picking up to 4-5ft (slightly bigger than forecast). 

This week (Aug 7-8)

This afternoon’s strong south swell is expected to peak overnight, and ease slowly through Thursday. However, a small reinforcing pulse of secondary southerly swell should maintain good waves across south facing beaches throughout the day. I’m not overly confident in the source of Thursday’s swell - there’s been so many unique swell sources from such a wide region of our south swell window in recent days - but all of the available data is pointing towards a fun day of waves at exposed beaches. 

Also, based on this afternoon’s performance I’m going to nudge up Monday’s estimates a little for Thursday, and expect 2-3ft sets at Sydney's south facing beaches for much of the day, with smaller waves elsewhere. The Hunter should see another foot or more on top of this (ie anywhere between 3ft and maybe 5ft). Conditions should be clean early with moderate W/SW winds however they will swing southerly throughout the day as a weak front crosses the southern part of the state. So, the early bird will catch the worm.

Friday is a complex day for surf. We’ll see gradually easing residual energy from Thursday for the most part, mainly an inconsistent 2-3ft across Sydney's south facing beaches and much smaller elsewhere (but bigger in the Hunter, as per usual). Winds are expected to be light and variable - offshore early, trending light to moderate onshore during the afternoon - however the key feature for us to be on the lookout for is the arrival of a solid long period southerly groundswell late in the day.

This new swell is expected to push across the South Coast by lunchtime, and is due into Sydney after 3pm, so I’m concerned that a slight delay on its arrival - of the order of an hour or two - could result in Sydney/Newcastle surfers seeing no appreciable increase in size before the sun goes down.

That being said, we are expecting some really strong energy to fill into the coast, and gut feel is that we'll see at least a couple of hours of action before dusk. The low/front generating this swell is tracking SW of Tasmania as we speak, and will push into the southern, then south-eastern Tasman Sea into Thursday morning. Core wind speeds are expected to reach 40-50kts and it’ll be working on an active sea state generated by strong pre-frontal activity.

This is expected to result in the development of a solid S’ly groundswell that should reach 5-6ft at Sydney’s south facing beaches (with smaller 3-4ft surf elsewhere), and possibly 6ft to maybe 8ft in the Hunter - but the key question is whether we’ll see this new swell arrive before sundown. I’ll update the comments (below) on Friday with observations from further south so that we can start to pin point its arrival into the afternoon. But as a general rule the Bondi surfcam will show this new swell best. 

This weekend (Aug 9-10)

Friday’s late arrival of southerly swell is expected to peak overnight or early Saturday morning. We’re looking at a slow easing trend throughout the day however there won’t be any shortage of size - early morning should hold 5-6ft at exposed south facing beaches from Sydney to the South Coast, reaching 6-8ft in Newcastle for a few hours before the easing trend sets in. However, beaches not open to the south will be smaller. Light NW winds are expected to keep conditions nice and clean for much of the day.

Saturday afternoon’s easing trend will then continue into Sunday, and similarly light offshore winds should maintain excellent conditions for the most part. Again, south facing beaches and the Hunter region will continue to see the upper end of the size range but there should be good surf just about everywhere. Certainly a great weekend for a road trip north or south. 

Longer term (Aug 11 onwards)

Another strong front/low combo is expected to track through the Southern Ocean and up into the lower Tasman Sea over the weekend, bringing a strong southerly groundswell to the region sometime around Tuesday, holding through Wednesday. More on this in Friday’s updated notes. 


blindboy's picture
blindboy's picture
blindboy Wednesday, 6 Aug 2014 at 6:04pm

Some solid sets on the northern beaches this afternoon. At least one 6ft on an outer reef wide open to the south. Semi-consistent in the 4ft range but the quality of the waves I saw didn't do the swell justice.

donweather's picture
donweather's picture
donweather Friday, 8 Aug 2014 at 12:53pm

This long period south swell still on track? Some of the other models have downgraded it somewhat?

matdjhughes's picture
matdjhughes's picture
matdjhughes Friday, 8 Aug 2014 at 4:05pm

Any joy on the weekend forecast yet?

thermalben's picture
thermalben's picture
thermalben Friday, 8 Aug 2014 at 4:08pm

Still writing it now.. will be up around 5pm.