Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Wed 21st Sep)

Forecast Summary (tl;dr)

• Chunky NE windswell building Wed, becoming sizey Thurs/Fri- strong NE winds Thurs, easing through Fri and tending N’ly\
• Leftover NE swell Sat AM, with a brief window of good winds before S’ly change
• Slight kick in short period S swell Sat PM, holding into Sun
• Small pulse in E/SE swell later Sun, holding into Mon, with light winds
• Monitoring a few small swell sources from mid next week- check back Fri for updates

Recap

A small S swell signal in the water yesterday provided some 2-3ft surf,  bigger 3ft on the Hunter, with clean conditions early before onshore winds kicked in. Small leftovers in the 2ft or less range today and a messy ocean as NE winds start to kick in, heralding the beginning of another NE swell/wind episode. Details below.

NE windswell just starting to build

This week (Sep 21-23)

A few tweaks to the upcoming NE swell event. The complex low and huge trough line (extending across most of Australia!) are still tracking across the interior as forecast, with a high in the Tasman generating a NE flow across the majority of the Eastern Seaboard. The pressure gradient is tightened as the low approaches with an increase in NE winds and swell expected through the end of the week. In contrast to last Fridays event, a small low exits the coast north of Coffs Harbour, which delays the offshore flow and maintains a N’ly wind across Central NSW. The return S’ly flow as another small low and front develop near Tasmania late Fri/Early Sat is expected to kick in early on the weekend. 

In the short run and NE windswell quickly builds overnight and into tomorrow. Expect size in the 4ft range, building into the 4-5ft range during the morning. Winds will be unruly. With the position of the inland low being further north than indicated on Mon there’ll plenty of E component in the NE. Possibly even E/NE at times. If you can deal with less than perfect surface conditions there’ll be heaps of chunky peaks with a left-hand bias at most open beaches.

Friday doesn’t look as appealing as it did at the start of the week, due to winds not being so favourable and size being downgraded a notch. The focus of the fetch is now located further north, so Central NSW will see smaller surf, still in the 4ft range. Nor-east winds will be persistent, although easing in strength during the day and possibly tending more N’ly through the a’noon.  In short, this Fri won’t be as mint as last Friday but there will still be plenty of waves on offer.

This weekend (Sep 24-25)

Just a brief window of offshore winds is expected Sat morning, and with leftover NE swell in the 3ft range on offer, thats the window to aim for. Otherwise, a trough line off the NSW Coast, linked to a low SE of Tasmania brings a rapid S’ly change up the NSW Coast. By early morning winds will shift SSW then S’ly, confining surfing to sheltered corners and bays. Through the a’noon, we’ll see some developing short range S swell, and a smidgin of long period S swell. With accompanying S’ly winds both of these swell sources will be of low utility.

Winds should quickly lay down through Sun as the Tasman Sea retreats into what seems to be it’s current residual state- a weak, troughy mess of ill formed low pressure areas. That should see a morning land breeze, with a S’ly component, before weak E’ly breezes kick in. Small S’ly swells in the 2-3ft range, ease back through the day. We’ll just flag that EC has a slightly stronger and more persistent flank of S winds around the weak low moving NE from near Tasmania on Sat/Sun. That may boost wave heights an extra foot or so Sun. We’re also expecting a small pulse of E/SE swell generated by a Cook Strait fetch Fri- that should add some 2-3ft energy through the a’noon (see below). We’ll review that on Fri. Pencil in a few fun beachies for Sun.

Next week (Sep 26 onwards)

Troughy pattern persists into next week. Monday sees a small blend of E/SE swell easing and small E/NE swell from a broad but poorly organised wind field in the South Pacific corridor NW of New Zealand. Expect some continuing clean 2ft surf with the odd 3footer.

A front pushing through Tues is expected to bring a S’ly change. Small background swells will likely be augmented by another round of short period S swell, with low quality and not exceeding 2-3ft. 

From Wed next week there are quite a few bits of the troughy Tasman we’ll be monitoring. A low may form off the NSW South Coast, generating S swell for Thurs/Fri, although no great size is expected at this stage. 

Another broad low pressure area is expected to linger around the top of the North Island, with a weak, but well aimed fetch of E/SE winds. That should hold a small signal of E’ly component swell late next week, in the 2ft range.

SE winds through the lower Tasman should also supply some small SE swell into the mix late next week. 

Another mid-latitude low may push through interior NSW late next week, bringing instability with no major surf potential at this stage.

As mentioned before, all these troughy systems will need constant revision as weather models struggle to resolve them. Check back in Fri and we’ll update all the potential scenarios next week and take a last look at the weekend.