Small southerly swells, then a punchy NE windswell

Ben Matson picture
Ben Matson (thermalben)

Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 26th September)

Best DaysTues/Wed: small pulsey S'ly swells with good winds. Thurs: punchy NE windswell, initially poor with N/NE gales but there's an outside chance for a late window of NW winds. Fri: small easing NE swell with offshore winds.    

Recap: Plenty of good waves across the region on Saturday with a strong easing south swell and a smaller reinforcing E’ly swell, both originating from different parts of a Tasman Low. Conditions were clean with mainly light offshore winds. Size then eased into Sunday frm both sources. Today we’ve seen another strong south swell fill into the coast offering 3-4ft sets at south facing beaches. Early light offshore winds have swung into a light to moderate afternoon sea breeze. 

Bondi this afternoon via our surfcam; still some size on offer though onshores are creating bumpy conditions

This week (Tuesday 27th - Friday 30th)

Today’s south swell will ease overnight and further into Tuesday, and conditions are looking clean with mainly offshore winds; veering NW in the morning ahead of a late SW change as a small front crosses the coast. South facing beaches should manage early 2-3ft sets though it'll probably become a little smaller during the day

Although the system that generated today’s swell has tracked rapidly into the eastern Tasman Sea, out of our swell window, it’s left a small closed low at the tail end of the fetch, just east of Tasmania. This will produce a small south swell overnight Tuesday and into Wednesday.

Tuesday’s late SW change will also display a trailing S/SW fetch parallel to the Southern NSW coast and it will also kick up another small new south swell for Wednesday.

The combination of these two sources should generate 2-3ft+ sets at south facing beaches for Wednesday morning (a little bigger in the Hunter, but smaller at beaches not open to the south), and conditions are looking pretty good with early light to moderate W/SW winds ahead of a freshening NE sea breeze into the afternoon.

Wednesday's south swell will then slowly ease through Thursday however we have much more significant developments across inland NSW, thanks to an approaching deep mid-latitude low pressure system that’s expected to slam the SA and Vic coasts later Wednesday and Thursday, renewing flooding rains across many regions too.

Strengthening N/NE winds along the NSW coast on Thursday look like they’ll reach gale force strength by the afternoon, which should produce large surf at NE facing beaches by late in the day, especially south of Wollongong. However due to the northerly fetch alignment, there’ll be a wide range in size across the coast, with the smallest surf likely to be across the Hunter region (2ft+). 

South from here we’ll see 3ft+ surf across the Central Coast mid-late afternoon, up to 4ft+ across NE facing beaches in Sydney, and from Wollongong to the Far South Coast we could see anywhere between 4-6ft as the swell reaches a peak late in the day (keep in mind that the upper end of this size range will occur towards dark, so it’ll be smaller across all coasts through the morning and early afternoon).

However Thursday's surface conditions are likely to be heavily wind affected by the N/NE gales. We are looking at a very late NW change but it’ll probably occur in the early evening, too late to be of any benefit to surfers. I’ll take a closer look at this on Wednesday to see if the models have sped up the change - conditions will improve very quickly once it the wind swings, so even a 3-4pm arrival would bear at least a couple of hours of clean punchy surf. 

The other unfortunate aspect of the timing of this wind change is that the swell source will cease around the same time, and with eleven hours of darkness we’ll lose a lot of size before sunrise Friday. So, expect the last day of the working week to see rapidly facing NE swell from Thursday - maybe some early 2ft sets across Sydney’s NE facing beaches (smaller to the north, but a little bigger to the south) but easing steadily during the day

Strong NW winds are expected to keep conditions clean, if somewhat blustery at all open beaches on Friday

This weekend (Oct 1 - Oct 2)

A strong blocking high east of New Zealand and the lack of a supporting ridge south of the Tasman Sea is expected to focus the approaching mid-latitude low pressure system towards the south-east, so the strongest winds around the low will be out of the western quadrant.

This means we’re unlikely to see a typical strong return southerly swell over the weekend as the broader system moves into the Tasman Sea. As such, Saturday currently looks like it could be tiny to flat across many coasts. 

However, westerly gales exiting eastern Bass Strait on Saturday may generate a small, acute south swell on Sunday. At this stage I have only low confidence on the chances of any surf from this source, as the fetch is modelled to be straight west in orientation (and ideally we need a touch of south, preferably W/SW or SW). 

But, this is the only possible source of new swell for the weekend - if it doesn’t eventuate we’ll be looking at potentially two flat days in a row. Yikes!

Next week (Oct 3 onwards)

There’s nothing major lining up for the longer term at this stage. 

It appears possible that a succession of fronts will traverse the lower Tasman Sea mid-week, which could lead to a building south swell mid-late next week, but this is still a long time away so let’s wait and see how the model updates perform later this week. 


geoffrey's picture
geoffrey's picture
geoffrey Tuesday, 27 Sep 2016 at 4:40pm

Gday guy, we still on track for that south swell in the morning for south facing beaches? Cheers mate

thermalben's picture
thermalben's picture
thermalben Tuesday, 27 Sep 2016 at 4:46pm

Yep should be.. synoptic still looking OK. Won't be epic but there's gonna be some fun peaky waves at south facing beaches.

geoffrey's picture
geoffrey's picture
geoffrey Tuesday, 27 Sep 2016 at 8:22pm

Thanks a lot mate

Craig's picture
Craig's picture
Craig Wednesday, 28 Sep 2016 at 8:43am

Solid waves over 3ft across Bondi.