Solid E/SE, then moderate S'ly swells for the short term

Ben Matson picture
Ben Matson (thermalben)

Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Wednesday 9th June)

Best Days: Thurs: solid E/SE groundswell with gusty offshore winds. Fri: combo of easing E/SE swell and building S'ly swell, with fresh offshore winds. Sat: Clean with a small, easing combo of swells. Sun: strong S'ly swell with mainly good winds (dicey in the Hunter).

Recap: Clean, easing S/SE swell Tuesday with early 3ft sets at south facing beaches, smaller through the middle of the day and into the afternoon. Continual easing trend today with winds tending more N’ly.

This week (July 10-11)

The forecast models have danced around a little over the last few days with this impending E/SE groundswell - upgrading slightly from Monday to Tuesday, then downgrading again overnight (note: our servers didn’t finish the 18Z model run - which is a rare occurrence - so the forecast graphs are currently showing 12Z data. The next update - 00Z - should be through around 4:30-5pm).

Nevertheless, satellite obs on Tuesday confirmed what the models were predicting - a broad swathe of 40-50kt winds off the west coast of New Zealand’s North Island, aimed squarely at the NSW South Coast. The leading edge of this swell is due to reach the coast this evening and by Thursday morning should be close to fifth gear in the surf zone.

I’m going to hold steady with my size predictions, that is for 5-6ft sets across exposed beaches of the Sydney, Hunter and Illawarra regions, reaching 6-8ft on the South Coast. However, just a reminder about these kinds of events: you may recall a couple of similar east swells earlier this year, which produced great results at most locations but dipped out across a couple of locales (I’m looking in your general direction, Central Coast). 

The reasons for such size fluctuations across seemingly similar coastlines are most likely due to local bathymetrical effects. Therefore, the take home point for tomorrow is: check all of the morning surf reports between Newcastle and Wollongong to get a gauge how this swell is performing across the coast, and monitor the MHL buoy data for the overall trend (if your local doesn’t seem to be picking up the swell, check further along the coast).

For surfcam visuals, the Manly cam will be your best tool to assess the surf in real time. Don’t check a single location and make your assumptions from there - these groundswells can produce funky changes at individual reefs/beaches with just incremental changes in the swell direction.

Thursday’s swell is expected to reach a peak before lunchtime, and will trend downwards throughout the afternoon - not by a great deal - however it may become a little less consistent. Winds will be moderate to fresh offshore (W/NW) through the morning and will probably ratchet up quite a bit into the afternoon so keep this mind if you’re planning on surfing a deep water location, as there’ll be a lot of wind up the face.

Wave heights will ease more steadily into Friday (very inconsistent 3ft+ open beaches at dawn, bigger on the South Coast) however we’ll also see a building south swell during the day, originating from a strong frontal passage through Bass Strait. This flukey source of south swell - which as I’ve discussed before, often produces very little size south of about Ulladulla, due to the ‘axis of refraction’ about the SE corner of the country - has been ramped up a smidge in the latest model runs and also brought forward in time, which means we should see nearly a whole day of solid south swell at exposed south facing beaches in Sydney and the Hunter.

By early Friday afternoon (if not before), sets should be pushing 3-4ft at these locations - possibly some bigger bombs in the Hunter - however everywhere else will be relying on the (fading) E/SE swell and will consiequently be quite smaller. Conditions will be clean and less blustery than Thursday with moderate W’ly tending W/SW winds. 

All in all, a couple of great days of waves for southern NSW.

This weekend (July 12-13)

Thursday’s east swell will become very small by Saturday (just a foot or two of inconsistent leftovers), so our focus will hold from the south for the weekend. Friday’s south swell will also be on the way out (maybe some early 2ft+ sets at exposed south facing beaches in Sydney, a little bigger in the Hunter) and a dropping trend is likely during the day.

However a new front tracking through the lower Tasman Sea early Saturday morning should bring a late afternoon increase in fresh southerly swell to the South Coast, and possibly the Sydney/Hunter regions if we’re lucky. Winds will be fresh W/NW for the most part, tending gusty SW on the South Coast in the afternoon.

Sunday is much more likely to see an appreciable increase in new S’ly swell from this source, with south facing beach likely to reach 3-5ft, bigger in the Hunter. Some coasts will however be at risk of a fresh S/SW wind during the day (mainly north of Sydney) but most other locations should revert back to a moderate W/SW breeze, tending SW during the day. So all up, there’ll be waves all weekend but Sunday should see the most size.

Next week (July 14 onwards)

Nothing significant on the long range charts at this stage. Most model guidance maintains a healthy southerly flow into the lower Tasman Sea over the weekend which should keep south facing beaches flush with fun, mid-period south swell through Monday and Tuesday.

There’s a few wild speculations in the model runs towards the end of the week and next weekend however they’re all quite divergent and not really worth discussing at length for a few days yet. Let’s check in on Friday to see how everyone did with the east swell.. hope you score! 

Comments

thermalben's picture
thermalben's picture
thermalben Wednesday, 9 Jul 2014 at 4:40pm

Latest model data has arrived and, as expected, re-upgraded tomorrow to 4-6ft (see Cronulla forecast graph below).

mitchvg's picture
mitchvg's picture
mitchvg Wednesday, 9 Jul 2014 at 4:58pm

Do you think the period will snick up to 13s+ Ben?

thermalben's picture
thermalben's picture
thermalben Wednesday, 9 Jul 2014 at 5:12pm

Should be more in the 14-15 second range for Tp I think (that is, the leading edge of the swell overnight.. it'll settle in around 12-13 seconds for tomorrow.. Tsig should reach 11 or maybe 12 seconds.

mitchvg's picture
mitchvg's picture
mitchvg Wednesday, 9 Jul 2014 at 7:45pm

Ok cheers, better check before suiting up then.

thermalben's picture
thermalben's picture
thermalben Thursday, 10 Jul 2014 at 5:29am

Ooooh baby! Swell kicked in around midnight, and winds are only light.

donweather's picture
donweather's picture
donweather Thursday, 10 Jul 2014 at 7:04am

Some impressive wave buoy readings even north of the border pre dawn too. Shame about the N'ly scarring.

stunet's picture
stunet's picture
stunet Thursday, 10 Jul 2014 at 7:42am

Couple of very solid 6' sets on the Coal Coast at first light. Winds only barely ruffling the surface too - pretty much non-existent, though started pufing when I left.

Great looking swell.

oiley's picture
oiley's picture
oiley Thursday, 10 Jul 2014 at 9:02am

huge sets rolling in along the sea wall rd.. losing shape a bit though, reckon it will be better when it starts to ease back a bit

thermalben's picture
thermalben's picture
thermalben Thursday, 10 Jul 2014 at 3:34pm

MHL buoy still holding in there nicely as we hit the mid-afternoon mark. Swell seems to have backed off a touch but apparently Cape Solander still has occasional 6ft sets.