Tiny weekend; strong south swell next week

Ben Matson picture
Ben Matson (thermalben)

Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Friday 24th July)

Best Days: No great days. Tiny waves for the weekend and most of Monday, and a large S'ly swell due Tuesday will be wind affected in general. Wednesday is probably the pick with better conditions and a solid easing S'ly groundswell.

Recap: A minor combo of NE and E/NE swells have provided small waves to the Southern NSW coast over the last two days, with generally clean conditions thanks to light winds.

This weekend (July 25 - 26)

If the swell models are to be believed, we’re looking at a small drop in swell height and a small increase in swell period into Saturday.

Essentially, all of our swell windows are devoid of any major activity so we’re having to look towards fluky swell sources for the weekend. And it doesn’t look promising. 

Right now a large Tasman high is drifting east across New Zealand, and a favourably aligned, if only moderate E/NE fetch is aimed into our swell window. Unfortunately, most of the winds are under 20kts but in the absence of anything else, its presence can’t be discounted. It is however weakening so its influence as a swell source is limited.

This fetch should supply a continuation of small inconsistent E/NE swell through Saturday morning, ahead of an easing trend into the afternoon and further into Sunday. Early Saturday should see the biggest waves (1-2ft at exposed beaches, tiny elsewhere), with smaller surf prevailing throughout the afternoon. Sunday will be lucky to see an occasional 1ft wave at the swell magnets, most beaches will be flat.

In Wednesday’s notes I discussed the chance for a minor south swell arriving late Saturday. However, the latest model data has nudged the fetch alignment extending east of Bass Strait slightly north of west, so this has completely ruled this out as being a swell source for Southern NSW. 

As for the weekend’s conditions, it’ll be clean just about everywhere with freshening nor’westers on Saturday tending W’ly on Sunday.  But if you can’t surf Saturday morning I really wouldn’t bother planning any water time.

Next week (July 27 - 28)

A deep low pressure system will pass east of Tasmania on Sunday afternoon, setting up south-westerly gales within our south swell window on Monday morning, that’ll generate a strong southerly groundswell for the entire NSW Coast. 

The models have pulled back the timing of this system a little, so much so that we may not see an appreciable increase until very late on Monday (the South Coast should see a solid kick early-mid afternoon though).

So, Monday will probably remain very small for much of the day across the Sydney/Newcastle region, with some minor sideband energy from the initial W/SW flow off the northern flank of the low (a foot or maybe two at south facing beaches) filling in through the middle of the day. We should see a bigger kick at south facing beaches in the few hours before COB - perhaps 3ft or maybe 4ft right on dark - but I think the proper phase of this swell will start to arrive overnight. 

Tuesday will not only see the largest surf from this system, but it’ll also see an early W/SW flow tending gusty S/SW early in the day thanks to the passage of a strong secondary front through the lower Tasman Sea. Interestingly, our surf model has pulled back its size estimation from this source to 3-5ft (south facing beaches) however I still think we’ll see solid 4-6ft sets at exposed south facing spots at some point on Tuesday, with a few bigger bombs in the Hunter. This is down a little on Wednesday's estimates, due to the models pushing the low east and not north-east through our swell window in their latest updates. Expect smaller surf at beaches not open to the south.

Regardless, you’ll have to find some shelter from the wind for much of Tuesday, apart for the early session across some regions such as the Northern Beaches.

By Wednesday morning the south swell should still be holding strong similar to Tuesday, and winds are expected to tend lighter W/SW as the pressure gradient relaxes. A slow easing trend is expected throughout the day.

The second half of next week looks like we’ll see light winds and slowly easing swell from the southern quadrant. There are no other major swell sources on the cards for the long term, but let’s check back Monday to see what’s popping up on the radar.


thermalben's picture
thermalben's picture
thermalben Monday, 27 Jul 2015 at 6:40am

Looks like the punt on the "minor sideband energy from the initial W/SW flow off the northern flank of the low" came off this morning - albeit a few hours ahead of schedule - how's these short period southerly lines off the Bondi surfcam this morning. 1-2ft but spaced very closely together. Doesn't seem to be showing up south of Sydney though, which isn't altogether unsurprising given the W/SW fetch source, and the likely axis of refraction.

thermalben's picture
thermalben's picture
thermalben Monday, 27 Jul 2015 at 6:41am

And.. 50-60kts exiting eastern Bass Strait. Impressive!

thermalben's picture
thermalben's picture
thermalben Monday, 27 Jul 2015 at 6:45am

Even more impressive is this 50-60kt fetch aimed fair and square into the southern Tasmanian coast. Will be interesting to see how big it gets across the South Arm today (this pass was late yesterday afternoon, so the resulting surf should have hit during the early hours of this morning).

This fetch is right on the periphery of Southern NSW's acute south swell window too. Depending on how the latest ASCAT/Windsat returns come back this morning, I may have to increase the forecast for tomorrow :)

chad schomberg's picture
chad schomberg's picture
chad schomberg Monday, 27 Jul 2015 at 3:22pm

Fuck yeah