Great weekend across Southern NSW; not much next week

Ben Matson picture
Ben Matson (thermalben)

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

Best Days: Sat/Sun: light winds and a fun, slowly easing SE swell with mainly light winds. 

Recap: Easing swells padded out Thursday morning though a new S/SE swell built into the afternoon originating from a Tasman Low, with exposed south facing beaches seeing occasional 3ft+ sets. There were also some reports of new long period S’ly swell glancing the coast during the day, though no buoys anywhere on the East Coast (NSW or Qld) detected this energy yesterday so it was likely a very faint forerunner signal.  Winds were S/SW so conditions weren’t great, but they did back off into the afternoon. The swell from the Tasman Low has levelled out this morning in the 3-4ft range, and the secondary southerly groundswell also reached the Eden buoy overnight (see the jump in peak swell periods to 15 seconds, below). This should continue to glance the Sydney region throughout the day though the S/SE swell will remain dominant. Winds are light W’ly across the region, though some locations are seeing moderate S'ly winds develop mid-morning. 

This weekend (Mar 25th - 26th)

The models have ever so slightly delayed the backside phase of the Tasman Low for today, which means it’ll remain active for a little longer than anticipated in Wednesday’s notes, and will therefore provide good quality surf for more of the weekend. 

Because of the low’s latitude and the alignment of the fetch, we’ll see the most size aimed into the Sydney and Hunter regions, with wave heights tapering off slightly south from the Illawarra to the Far South Coast. South facing beaches from Sydney northwards should pick up 3-4ft sets for much of Saturday. Expect smaller surf elsewhere. 

The long period S’ly groundswell due today will also ease into the weekend so expect the S/SE swell to remain as the dominant energy.

Surf size will then continue to abate through Sunday, with 2-3ft+ sets at south facing beaches north of Sydney early morning, easing to 2ft throughout the day. Again, surf size will be smaller elsewhere.

A weak troughy pattern over the weekend will maintain generally light variable winds. Now, “variable” implies any direction - so it’s possible we may see some form of onshore at times (biggest risk is a moderate N/NE breeze on Saturday afternoon) but for the most part conditions should be very good, especially in the mornings.

Next week (Mar 27th onwards)

Still nothing amazing expected next week. The weekend’s swells will bottom out into Monday, and winds will freshen from the NE though no major surf is expected for this source. 

A shallow S’ly change will push across the coast on Tuesday, again without sufficient strength behind it to generate any new swell. We may see some small NE swell from Monday’s freshening breeze but the South Coast is more likely to see a workable size range, with Sydney expected to remain pretty small in the 1.5ft range tops. However, there is a chance we may see this upgraded over the weekend.

As mentioned on Wednesday, the Tasman Low's track over the weekend pushes it near New Zealand and the models are suggesting a very small but tight E'ly fetch will develop along its southern flank. However as feared, they’ve downgraded this in the latest runs so I’m not expecting much energy from this source through the middle of the week. I’ll take a closer look on Monday but for now it’s not shaping up to deliver much size. 

Otherwise, we are looking at small flukey swell sources for the long term. The Southern Ocean storm track will be aimed away from our swell window and the only possible systems of note are a small stalled trough in the lee of Tuesday’s southerly change (low to moderate local swell potential right now), and some indications of developing tropical activity south of Fiji during the middle of the week - though without any substance at the present time.

A tropical cyclone is also expected to impact Northern Qld early next week but this is nowhere near our swell window (or even SE Qld’s for that matter) so don’t expect to see any swell from this region either. 

Have a great weekend! See you Monday. 

Comments

geoffrey's picture
geoffrey's picture
geoffrey Friday, 24 Mar 2017 at 8:39am

Friday morning report hey Ben... bucks weekend? Bender? Vegas?

thermalben's picture
thermalben's picture
thermalben Friday, 24 Mar 2017 at 9:06am

Hah! Not quite. Gotta hit the road this afternoon so wanted to get things out of the way nice and early.

geoffrey's picture
geoffrey's picture
geoffrey Friday, 24 Mar 2017 at 4:32pm

all good mate im just hassling you. pumping day of waves@!!

thermalben's picture
thermalben's picture
thermalben Friday, 24 Mar 2017 at 10:34am

Here's a great example why I usually prepare the Forecaster Notes towards the end of the day.

I'm now receiving some reports of bigger surf this morning across Southern NSW, with sets in the 4-5ft range.

Right now, I'm not sure (yet) whether this will have any effect on the weekend surf forecast - generally speaking, forecasters will use analysis conditions (i.e. current surf reports, surfcam vision, and buoy data) to validate the model output.

In this case, our Northern Beaches data point - see below - had 3ft out of the S/SE all day today, with slightly bigger waves at 6am around 3-4ft.

The model then maintains similar periods through Saturday but with a very gradual easing of swell heights. With local winds expected to be be light - therefore reducing the possibility of local windswell contamination in the buoy data (or forecast output) - we can be reasonably confident that these figures are mainly representative of regional groundswell.

So right now I'm reluctant to upgrade the weekend forecast (i.e from 3-4ft to 3-5ft Saturday, and from 2-3ft+ to 3-4ft Sunday). But, had I not committed to writing these notes early in the day, I would have been able to monitor conditions throughout the day and assess whether these reports were a local anomaly, or if they were indeed representative of the wave model undercalling this swell event (or, swell events.. remember there's also a flukey long period S'ly swell in the mix).

Ahh, ain't it fun being a forecaster?

alexsmith1's picture
alexsmith1's picture
alexsmith1 Friday, 24 Mar 2017 at 12:32pm

Ben, not sure where your source came from however a reliable south swell reef on the NB was seeing 4 maybe 5ft waves every 10-15 or so minutes.

thermalben's picture
thermalben's picture
thermalben Friday, 24 Mar 2017 at 3:56pm

Thanks mate.. appreciate the feedback!

thermalben's picture
thermalben's picture
thermalben Saturday, 25 Mar 2017 at 11:25am

Nice SE lines across the Manly stretch.

thermalben's picture
thermalben's picture
thermalben Saturday, 25 Mar 2017 at 11:34am

Not many takers at the Island (standup on an inside bowl).

thermalben's picture
thermalben's picture
thermalben Sunday, 26 Mar 2017 at 6:46am

Smaller today but jeez there are some nice lines pushing through Maroubra this AM.



thermalben's picture
thermalben's picture
thermalben Sunday, 26 Mar 2017 at 8:03am

Good size range indicator at Maroubra.

Westofthelake's picture
Westofthelake's picture
Westofthelake Sunday, 26 Mar 2017 at 6:42pm

Got to the beach at 7am this morning (south of Caves) and between then and 9 it was pretty consistent with sets coming in at 4-5 feet. On a side note it is good to see a cyclone in the coral sea but sadly it is nowhere near our window, and even worse is that it's going to hit landfall with a vengence.