Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Wed 7th Sep)

Forecast Summary (tl;dr)

• Longer period SSE pulse Thurs, with freshening N to NE winds
• NE windswell likely Thurs PM, holding  Fri AM with winds improving through the day as swell drops
• Very small this weekend
• S to SE swell likely Tues/Wed next week with front/low forming in Tasman, low confidence on specifics, check back Fri
• Unstable Tasman Sea, troughy La Niña pattern continues, stay tuned for updates

Recap

Plenty of size since Mondays notes, as swell pulses from a Tasman low continue to make landfall. Yesterday saw chunky 4-6ft surf, more from the  SSE with some long period S swell in the mix (compared to Mondays more E-ESE pulse) clean under W’ly winds. Today has seen a reinforcing pulse of SE swell which is maintaining surf in the 4-5ft range, with some bigger sets on the Hunter. Conditions are clean early under a W to NW flow, with NE winds kicking up through the a’noon. All in all, another handy run of swell. 

Bluewater, plenty of energy and a La Nina signature in the background

This week (Sep7-9)

The Tasman low is out of the swell window and a large high is now moving over Tasmania to take up position in the Tasman Sea at a southerly latitude typical of the high pressure belt under the La Niña phase of the ENSO cycle. The high will move E with a N’ly flow rapidly developing as pressure gradients get tightened by an approaching front, complex low and trough line.  That will dominate the rest of the week and weekend with the low moving out into the Tasman in conjunction with a series  of cold fronts early next week.

In the short run and NE winds will really strengthen through tomorrow, so get in early for cleanest conditions, where a NW flow will be brief. A last pulse of long period SSE swell generated by a flare-up of he polar low as it passed well to the south of the South Island is expected to generate some inconsistent sets to 4ft, bigger 4-5ft on the Hunter, making S facing beaches well worthy of investigation. Expect increasing amounts of NE windswell to 3-4ft to develop through the a’noon as a proximate fetch of NE strong breezes to high winds quickly whips up short period sidewinders.

This should be the dominant swell source Fri morning , with just a smattering of leftover SSE swell with sets to 3ft, easing during the day. Early N’ly winds will tend NW through the day as the frontal/trough system approaches, opening up a window of fun surf on the beaches. 

This weekend (Sep10-11)

Still looking very quiet this weekend, surf wise. The frontal system and low will drive a mostly W’ly flow across the NSW Coastline for the majority of the weekend so conditions are expected to be clean.

Expect a small blend of leftovers swells from the NE and SSE, biggest Sat morning with some 2ft sets and easing back through the day into the 1ft range. Fun for learners and kids.

Similar size range Sun, with weak E/NE swell from a residual patch of NE-E/NE winds in the Northern Tasman supplying some 1-1.5ft surf with light winds, mostly offshore. Should be a pleasant day for some splash and giggle.

Next week (Sep 12 onwards)

Still a fair amount of model divergence happening which suggests more tweaks to the forecast for next week on Friday.

EC continues the stalled low, with a resultant W’ly flow maintaining through Tues, before a weak low forms in the troughy remnants of the weekends instability. That would suggest small surf Mon, with a small pulse of S swell Tues from a passing front, before a couple of days of small SE swell as the low sits off southern NSW.

GFS is much more bullish, with a major front bringing a stiff S’y change Mon PM, and a chunky S swell for Tues/Wed in the 4-5ft range with S to SE winds. 

Looks like another round of NE winds towards the end of next week, with another mid-latitude low and trough approaching from the W. This period of instability and enhanced troughiness reduces confidence in even medium range forecasts, due to models struggling to resolve the extra dynamism in the atmosphere. 

Without any major swells on the radar for early next week, we’ll pencil in a S quadrant swell for Tues/Wed and see how it’s shaping up when we come back Friday.

Seeya then.