Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 7th September)

Best Days: Plenty of surf for the entire forecast period (smallest early Tues) but with tricky winds.

Recap: Small surf played out all weekend and into today, with a mix of S’ly and NE swells providing slow 1-2ft sets. Winds were light through the mornings ahead of moderate afternoon sea breezes. 

This week (Sep 8 - 11)

Small surf will prevail for the short term, though it won’t become totally flat. 

A series of peripheral sources - a poorly aligned ridge through the Coral Sea (generating background E/NE swell) and a firm ridge against the coast (generating local N/NE windswell) will keep the open beaches active with peaky 1-2ft sets building to 2ft+ late Tuesday. Bigger sets in the 3ft+ range are likely on the South Coast from the NE, due to a longer fetch length.

Size will ease from the NE on Wednesday as the fetch retreats to the north overnight. 

Some minor S’ly swell may glance south facing beaches over the coming days, sourced from distant frontal Southern Ocean frontal activity, but I’m not expecting much size here. 

N’ly winds will freshen throughout Tuesday and become quite gusty into the afternoon, ahead of a S’ly change pushing up the Southern NSW coast on Wednesday morning, reaching Sydney before dawn and Newcastle shortly after.

A robust fetch trailing the change will generate short range S’ly swells to 3ft+ at south facing beaches by the afternoon, though no major quality is likely under the accompanying southerly breeze.

The rest of the week looks interestingly complex.

Wednesday’s change will be reinforced by a ridge across the eastern states, maintaining moderate to fresh S/SE winds across most regions on Thursday, easing Friday. So, local conditions won’t be great but the associated fetch will be quite broad, and there’s a suggestion we could see a small trough form in the western Tasman Sea into Friday (though this isn’t clear yet).

The upshot is that we’ll see persistent S/SE swells in the 3ft+ range on Thursday, with a possible bump to 4-5ft on Friday depending on how/when this trough develops. Even if it doesn’t, some of the other atmospheric solutions strengthen the synoptic flow through the north-eastern quarter of the Tasman Sea and this will result in building SE swells across Southern NSW anyway, just smaller in size. 

At the same time, we’ve also got some inbound E/NE swell from an unrelated trough developing north of New Zealand this evening (see below). It’s not aimed very well within our swell window but should generate 3ft+ of new swell through Thursday afternoon and Friday. 

Now, local winds certainly don’t look great, and Friday is your best chance for a reasonable easing in strength and some OK waves at protected southern ends. I’ll fine tune the details on Wednesday.

This weekend (Sep 12 - 13)

Confidence is currently low on this weekend’s surface conditions, due to the divergent model guidance.  

However, there won’t be any shortage of swell. The remnants of our mid-week S’ly change will merge with tropical moisture in the north to form a decent swell generating system in one of our eastern swell windows, and wave heights could reach 4-5ft+, most likely on Saturday, before easing Sunday.

However, it’s too early to be sure as to the local winds, so let’s make another assessment over the coming days with the availability of more data. But, I’m quietly confident there’ll be plenty of solid surf around and we should see at least one decent window of opportunity to capitalise on.

Next week (Sep 14 onwards)

Lingering instability from the lower Coral Sea through the Tasman Sea is expected to see our eastern swell window very active into the lower term period. As such, I’m expecting an extended run of surf out of the E/NE through next week. More on this in Wednesday’s update.