Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Fri 24th Dec)

Forecast Summary (tl;dr)

• Small blend of surf on XMas Day morning with a SSE groundswell filling in during the day, mostly light winds tending NE and freshening, possible slack winds due to a'noon storms
• Inconsistent SSE groundswell Boxing Day favouring S facing beaches with a gusty S'ly change likely in the morning, early window of lighter NW winds more likely on the Hunter
• Increasing short range SE swell likely Mon PM, peaking Tues, slowly easing Wed
• Longer period S swell likely Mon, holding Tues morning before easing
• Easing surf later next week, with NE windswell likely developing Fri
• Still tracking tropical developments, very dynamic/changeable set-up, check back Mon for latest revisions

Recap

More of the same small surf has filled out the week, with yesterday seeing mostly 2ft waves through the region, quality being degraded by an E’ly flow. A window of light NW winds this morning , more prominent on the Hunter, saw some clean 2-3ft surf, predominantly from the S quadrant. Smaller 2ft or less through the rest of the f/cast region. A trough induced S’ly change ruined most surf in the South of the region, with winds over 20 knots. Further north windspeeds were lighter, allowing a few more options for a rideable wave. All in all, there’s been a small, rideable wave every day this week if you weren’t too fussy.

Hight tide swallowed up most of the small swell on offer

This weekend (Dec 25 - 26)

No great change to the Xmas F/cast. The day starts out with light winds, more likely NW or even W/NW on the Illawarra, more N’ly north of Syd on the Hunter. Expect a small blend of surf in the 2ft range early, with S/SE groundswell filling in through the morning. This will be Lully and inconsistent swell and likely with significant variations between surf spots dependent on S’ly swell exposure and ability to make the most of the longer period by bathymetric focussing. Most spots will see 2ft waves with a few select magnets and reefs seeing some bigger 3ft or even 3ft+ sets. Expect winds to freshen from the N and swing NE during the day. A trough line we mentioned on Wed is now expected to remain well south of Jervis Bay with minimal impact on local winds in the f/cast region. Nonetheless we can’t rule out an a’noon thunderstorm which gives a chance of a late arvo glass off.

Boxing Day sees the trough move north, bringing a S’ly change in the early morning. Looks like there will be a window of lighter NW winds on the Hunter early morning but you’ll need to get your skates on to get a go out before the Sly kicks in. Leftover sets from the S/SE in the 2-3ft range at S exposed beaches will be severely wind affected as the S’ly gets up in excess of 20 knots. Once that happens surf will be confined to much smaller heights at sheltered locations. A small amount of short period S’ly windswell will be whipped up through the a’noon for the super keen, unlikely to exceed 2-3ft.

Next week (Dec 27 onwards)

As discussed on Wed, we see a major pattern change next week after the troughy doldrums pattern this week. A strong front with severe gales passing well to the south of Tasmania sets up some S’ly groundswell early next week and a strong high pressure ridge surges up the East Coast, becoming stronger as it moves north from the Mid North Coast. 

That means we will start the week with fresh S to SSE winds Mon as the ridge becomes established. There’ll be some long period S swell in the water, likely in the 3ft range, bigger 3-4ft on the Hunter, mixed in with plenty of short period S/SE windswell building to 3-4ft generated by proximate strong winds developing off the NSW South to Central Coast. Thats going to make it challenging to find a quality wave through Mon, you’ll have to sacrifice most of the size to find anything clean.

The high pressure surge up the coast sees the focus of the strongest winds move north out of the Central NSW region through Tuesday. That will leave a lingering moderate S/SE to SE flow, possibly lighter SW inshore early, more likely north of the Harbour. A mix of short period SE swell and longer period S swell will peak in the 3-4ft range at exposed breaks, bigger 3-5ft on the Hunter, and will likely still be severely wind affected and ratty. Again, it’s likely surfable options will be smaller due to the need to get out of the wind. 

Despite our bullish outlook on Wed, surf should decrease throughout the region from next Wed onwards. The trough/low expected to form off the Mid North Coast is no longer being modelled, which means a diminishing high pressure ridge, with winds tending NE through Thurs and Fri.

Expect smaller surf to become entrenched through Wed as the proximate SE/ESE fetch moves northward. Size in the 2-3ft range will likely ease back down to 2ft during the day. Light winds offer the cleanest conditions of the week.

Going into the end of 2021, Thurs is likely to be a low point, with residual surf from the E in the 2ft range, possibly tending to NE windswell later in the day as NE winds start to kick up.

Fri has better odds for NE windswell as the fetch lengthens along the NSW Central Coast, although it looks to favour the South Coast at this stage. Lets pencil in 2-3ft surf and see how the fetch shapes up on Mon.

Longer term and our tropics are firing up, although it seems a case of endless false alarms in the last few weeks.

Models have been interested in the start of the Northern Australian Monsoon (NAM) as the year ends, suggesting a tropical low tracking across the Northern Territory into the Gulf of Carpenteria and then across Cape York Peninsula into the Coral Sea towards the end of next week.  Major models significantly diverge on the fate and surf potential of the tropical low once it enters the sphere of the Coral Sea. 

EC maintains the low inland through the QLD interior, with a limited fetch infeeding into the system, tracking down the QLD coast and possibly stalling on the SEQLD coast as the system washes out. 

That scenario has very limited surf potential for Central NSW. 

GFS stalls the low off the North QLD coast, with another separate low possibly undergoing cyclogenesis west of Vanuatu. The cradling high sees a long fetch of E/SE winds form across the Coral Sea, with potential for E/NE swell to eventually develop through radial spread, as well as more direct swell if any cyclone moves south.

With so much model divergence we will just have to wait and see how it pans out before making any calls into the New Year. We will monitor development closely over the weekend and report back in on Mon and see how it’s shaping up.

Check back then for a full update and in the mean-time have a great Christmas.

Seeya Mon.