Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Fri 7th Oct)

Forecast Summary (tl;dr)

• Tricky weekend wind outlook as trough/low deepens off coast- NW winds likely Sat AM- possibly tending S’ly from Illawarra south
• Winds tending SW through Sun as low deepens but check local wind obs as winds vary across region
• Small mix of swells Sat
• Chunky NE swell Sun with spike in S swell likely through the a’noon
• Plenty of S swell Mon AM, slowly easing through the day and into Tues AM
• Plenty of E/NE tradewind swell developing through Mon-Wed next week with light winds
• Stronger E’ly swell on the radar from Wed-Fri next week from large E’ly fetch in South Pacific, check back Fri for updates
• Slow easing E swell into next weekend

Recap

Messy surf in the 4ft range made landfall yesterday- mostly E-E/NE with some stray S’ly groundswell in the mix. Onshore winds blew most of the day. Conditions have improved a notch today under lighter N’ly breezes although they are far from groomed. NE swell is dominant this morning in the 3-4ft range with some continuing stray longer period S’ly energy low down in the mix. Dynamic weekend ahead as a surface trough/low forms close to Sydney. Details below.

Unruly but plenty of E/NE energy in the water

This weekend (Oct 8-9)

Whoa, still a very tricky wind outlook for the weekend as a trough emerges around the Sydney region and forms a small but robust low later Sat into Sun (see below). The exact position of the trough line is still subject to model variance so we’ll have to factor in a high error margin and minute by minute wind shifts.

A north-west flow looks likely for most of the region Sat morning with areas from the Illawarra southwards likely to see S’ly quarter winds develop around lunch-time. These winds should stay more N’ly north of the Harbour. If the trough line creeps north during the day expect S’ly quarter winds to develop north of the Harbour, up to the trough line, which is likely to stay S of the Hunter. In short, keep tabs on your local wind obs and be prepared for wind shifts.

Surf-wise we’re looking at a 3-4ft blend of E/NE-NE windswell and  the last of the longer period SSE swell. Surf quality dependent on local winds. 

A low is expected to form in the trough line overnight Sat and leading weather models do suggest that will lead to fresh SW-S winds by sunrise Sun morning. GFS has a later evolution of the low, with an area of NW-N winds north from the Central Coast before winds tend W then fresh SW-S. Again, keep tabs on local wind obs. Factor in small changes in timing and position of the developing low will create material differences in winds, often in close proximities.

Complex outlook for surf on Sunday. A NE infeed into the developing low is likely to spike NE windswell Sun morning with size to 4-5ft. As the low winds up and forms gales in close proximity to the coast a fast rising S swell is on the cards for Sun a’noon. Confidence is still quite low so close to the event but surf in the 5-6ft range is on the cards at S exposed breaks.

Phew. It’s a very dynamic, coastal outlook.

Next week (Oct 10 onwards)

The low is expected to move away quickly later Sun, leaving plenty of S swell through Mon morning, likely in the 3-5ft range at S exposed breaks. Mixed in with that will be smaller 2-3ft E/NE swell, which marks the early stages of an extended swell event from the Coral Sea/South Pacific. A weak high pressure ridge should see light land breezes tending to light E’ly breezes during the day.

Light breezes are expected to continue through the first half of next week under the influence of a weak high pressure ridge and troughy coastal environment. They should be more SE-ESE Tues with a tendency to clock more E/NE-NE through Wed a’noon. 

We’ll see a slow and steady building trend in E/NE swell through this period. Up into the 3-4ft range Tues, where it will mix with easing but still strong S swell which should hold some 3-5ft sets Tues AM. By Wed we should see size from the E/NE into the 3-5ft range. Along this increasing trend swell period should inch up so expect a muscling up in power as well as size.

This muscling up continues into Thurs and Fri with size to 5-6ft.  N’ly winds increase Thurs with the approach of a trough/front.

Through Friday the arrival of the front is likely to see winds swing NW-W, which could not be better timed with a solid E/NE swell in the water. No doubt we will see some revision on timing next week but factor in the potential for good/great surf towards the end of next week.

Longer term and it looks like we will see a slow winding down of E swell into and through next weekend under light winds. We’ll be looking at another potential fetch developing off the North Island later next week, possibly a source of E swell. At this early stage it doesn’t look as exciting as the upcoming swell generator. 

Check back Mon for the latest and have a great weekend!