Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 9th September)

Best Days: Wed: rapidly improving conditions with a good, solid mix of S/SE and E/SE swells. Thurs: clean conditions, and a nice blend of easing E/SE swell and some new long period S'ly swell. Fri: smaller, easing S'ly swell with good morning winds. Sun: large S'ly swell easing with light winds. 

Recap: As expected, Friday afternoon’s punchy NE swell was almost completely gone by Saturday morning, and most of the day remained very small with offshore winds. New southerly swells built throughout Sunday, a little more slowly than expected and not quite reaching the predicted height. South facing beaches across the Sydney region pushed up to 4-5ft by the afternoon, with larger waves in the Hunter, but it was smaller at beaches not as open to the south. Today has seen a temporary drop in size this morning (3ft+ Sydney south facing, 3-5ft Hunter) but a new S’ly swell is building across the coast as winds swing strong S’ly.

Still some pockets on the Cenny Coast this arvo

This week (Sep 10 - 13)

Tuesday will see a continuation of this afternoon's imminent large windy waves.

A strong pressure gradient between a large Tasman low and a high over the Bight will maintain fresh to strong southerly winds, though they will ease back in strength. One or two regions may see pockets of morning SW winds but they’ll be the exception rather than the rule. 

The models are showing quite a bit of size for the next few days but I think it’s probably overcooking things thanks to a significant level of windswell contamination in the mix. Regardless, it won’t be small: south facing beaches should see 6-8ft surf and it’ll be bigger across the Hunter in the 8ft+ range. Beaches not completely exposed to the south will be much smaller; in any case your best options will be across sheltered southern corners. 

On Wednesday, local winds will ease considerably as the low moves further into the Tasman Sea, relaxing the pressure gradient across the coastal margin. We’ll see a mix of easing S/SE swells from the bottom of the fetch, plus some E/SE swell from a fetch developing west from Cook Strait today (the body of water separating New Zealand’s North and South Islands).

South facing beaches should see 4-6ft sets early morning, easing through the day. Conditions may be slightly lumpy to begin with but will be quickly improving. Note: the E/SE swell may be slightly delayed early morning.

By Thursday morning most of the S/SE swell will be on the way out but there’ll be some lingering 3-4ft+ sets out of the E/SE from the NZ fetch, however this will abate through the day. 

At the same time, the leading edge of a long period S’ly groundswell will make landfall, having been generated by an intense low well south of the continent today (see below).

This system is poorly aligned within our (acute) south swell window, but core winds are in the 50-55kt range and this will generate large swell periods near 18-19 seconds. They’ll bend into the Tasman Sea and push across Southern NSW during Thursday (morning across the South Coast, after lunch across the Sydney/Hunter coasts), however this swell will be extremely fickle, only favouring a small number of reliable south swell magnets with inconsistent 3-4ft+ sets. Offshore winds from the W/NW should keep most locations clean. 

This flukey south swell should persist into Friday morning but an easing trend will become quite apparent during the day (non-south swlel magnets will be pretty small by this time).

We may see a small late kick in short range S’ly swell from a modest front pushing through the lower Tasman Sea overnight Thursday, but no major size is expected. A gradual wind change to the south is also on the cards during the day, though probably without any great strength. 

This weekend (Sep 14 - 15)

There’s stacks of south swell in store for the weekend.

The front tracking under Tasmania late Thursday will kick up some reasonable south swell for Saturday (arriving late Friday, probably overnight) but an unrelated front - quite powerful - will push in on top of this swell, generating a more dominant short range event that should push south facing beaches into the 6-8ft range by the afternoon.

Fresh SW tending S’ly winds will accompany Saturday’s upwards trend, but Sunday looks to be the pick at this stage with light variable winds and steadily easing size from a similar size range. 

Next week (Sep 16 onwards)

This recent pattern of mid-latitude lows pushing through the Tasman Sea looks like they'll continue in some shape or form for the foreseeable future. It looks like next week will exhibit similar surf characteristics to this week, though I’ll have to leave it a few more days to fine tune the specifics. More on Wednesday!