Large storm swell Tuesday; good windows from Wednesday onwards

Ben Matson picture
Ben Matson (thermalben)

Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 20th April)

Best Days: Tues: unusual waves at novelty locations. Wed: large combo of easing SE windswell and new SE groundswell, and a possible wind shift to the S/SW then SW (and subsequently improving conditions). Thurs: Solid but steadily easing SE tending S'ly swell with better conditions. Sat: small E/NE groundswell with offshore winds. Sun: strong building S'ly swell with offshore winds. 

Recap: Small leftover swells all weekend with a rapid increase in short range S’ly windswell late Sunday behind a southerly change. Pretty uninspiring all round. Steadily building SE swell all day today with strengthening S/SE winds (Wattamolla just recorded a gust of 65kt - 120km/hr - which is hurricane strength!).

This week (Apr 21 - 24)

No surprises to see a total washout today. Whilst Sunday’s size estimations were pretty close (with the building S’ly windswell), it was undersized this morning and the upwards trend today has been slow. But this is certainly not unusual for these kinds of close-proximity, dynamic weather systems. 

The broader synoptic outlook is a little complex as the atmospheric models have a couple of solutions possible for the next few days. Most models have an ECL deepening in the vicinity of Seal Rocks through Tuesday, of which gale to storm force S/SE winds along its southern flank will create very large seas and swells for most regions (biggest in the Hunter, with slightly smaller surf and easing winds as you track south). 

Side note: When is an east coast low not an East Coast Low? Read Craig Brokensha's article here.

I’m not sure if it’s worth putting a size estimation on things as there’ll be little surfing opportunities at most locations, but we’re probably looking at 10-12ft surf across the exposed Hunter coast, 8-10ft+ in Sydney, and then 6-8ft+ south from the Illawarra (smaller in the Far South). Winds will be strongest in the Hunter (40kts+) but will ease slowly with increasing southerly latitude. Expect a S/SE flow for the most part but it should tending southerly throughout the day. 

Tuesday’s fetch will weaken throughout the afternoon and overnight, so this swell source will abate into Wednesday. However, the GFS solution has a secondary low pressure centre in the central Tasman Sea that’s expected to intensify and retrograde back to the coast. This enhancement on top of a very active sea state should generate a strong secondary push of better quality groundswell that’s expected to push across most beaches on Wednesday - probably not early morning, more likely during the middle of the day.

Now, I’m taking a punt in calling this secondary swell because it’s going to be little hard to decipher from the residual noise leftover from Tuesday (I think the new pulse should be worthy of 6-8ft+, and this could be the residual size range left over early Wednesday). And, the models are not in close agreement with the synoptic evolution from Wednesday onwards either (I’m leaning with GFS as it’s been pretty good on this system so far).

But what gets me slightly excited about Wednesday’s surf prospects is that winds are expected to veer S/SW throughout the day, maybe even SW in some areas, as the primary low (near Seal Rocks on Tuesday) moves offshore and broadens into a more typical ‘Tasman Low’ structure. 

So, boiling this all down and we’re probably looking at 6-8ft+ surf at exposed spots through Wednesday, with a noticeable kick in definition through the middle of the day and into the afternoon. Keep an eye on local wind observations as this directional shift could really start to favour quite a few breaks, and would lead to a steady improvement right across the region. 

As per normal I’ll update observations and other information in the comments below through Tuesday and early Wednesday.

For the rest of the week, it’s a little hard to be totally confident as the model guidance is a little mixed, but we’re looking at strong but steadily abating wave heights from Thursday onwards (from the SE, tending S’ly) and rapidly easing SW winds on Thursday tending W’ly on Friday

We may also see some moderate E/NE swell from a broad infeed into the Tasman trough associated with the ECL, but this currently looks like it’ll be best aligned towards the South Coast and Tasmania’s East Coast (maybe some 3ft sets through late Thurs/Fri if we’re lucky). I’ll have a closer look at this on Wednesday.

This weekend (Apr 25 - 26)

We’ve got a couple of swell sources for the weekend.

Our southerly swell will be all but gone by this time, however Saturday should see a combination of easing E/NE swell (feeding into the central Tasman trough) plus a small long range E/NE swell from a developing tropical system north-east of New Zealand over the coming days. Set waves should be somewhere in the 2-3ft range - albeit quite inconsistent - and it’ll be nice and clean with freshening W’ly winds. This swell should continue through Sunday.

Also for Sunday, we’re looking at another strong front crossing the SE corner of the country that looks like it’s going to extend SW gales out of eastern Bass Strait early in the day.

We’re ultimately looking at a couple of days of strong southerly swell from the broader system, the first of which should start to build through Sunday - but with winds maintaining a W/SW direction -  so conditions should remain nice and clean on the surface. Early estimates are for 4-5ft at south facing beaches by Sunday afternoon but I’ll have a better idea on this in Wednesday’s update.   

Next week (Apr 27 onwards)

More strong south swell for Monday onwards but with winds probably veering more southerly at times (early sou’westers likely though). This will be our primary focus through the first half of next week and could get quite sizey at times, somewhere north of 6ft at south facing beaches on Monday and Tuesday, with a probably easing trend Wednesday onwards. Let’s see how the model updates pan out over the remainder of the week.

Comments

Tim Bonython's picture
Tim Bonython's picture
Tim Bonython Monday, 20 Apr 2015 at 9:01pm

Tell that low system. 'Thx for coming.' Only good for farmers & the dams.

erikb's picture
erikb's picture
erikb Monday, 20 Apr 2015 at 10:00pm

Is there an easy way to look up old swell data? specifically 3rd of september 2014 (if my camera has the right date set on it) Trying to work out this novelty spot...

thermalben's picture
thermalben's picture
thermalben Tuesday, 21 Apr 2015 at 5:41am

Last night was the windiest night I can remember in a long time. And we've been without electricity since about midnight. Feel like it's going to be a long, slow cleanup process here today (if that's possible.. It's still howling).

Radar imagery shows the low is very intense and located near Nelson Bay. To that end, Newcastle Nobbys picked up a wind gust of 75kts (135 km/hr) at 5am! Wouldn't be surprised if my (large) forecast surf ends up being undersized either. Not that there'll be any options with hurricane force winds...

Now, where did I put those bloody candles?

mick-free's picture
mick-free's picture
mick-free Tuesday, 21 Apr 2015 at 6:47am

Was a crazy flight into Sydney last night. Pilots sure earned their cash. We just lost the sign off the factory. Fully got blown off the building this morning. Been there 35 years. Going to be some serious cleaning up.

Maybe some waves in the harbour??

ACB__'s picture
ACB__'s picture
ACB__ Tuesday, 21 Apr 2015 at 12:09pm

Maybe ;)

erikb's picture
erikb's picture
erikb Tuesday, 21 Apr 2015 at 2:15pm

I was just there, shame aquabumps had to spoil it for everyone...

Craig's picture
Craig's picture
Craig Tuesday, 21 Apr 2015 at 2:37pm

He was at Shark Beach..

ACB__'s picture
ACB__'s picture
ACB__ Tuesday, 21 Apr 2015 at 2:43pm

yeah he was further in.

This was ruined by social media. #instagram

erikb's picture
erikb's picture
erikb Tuesday, 21 Apr 2015 at 2:56pm

Ok my bad then, kinda, everyone in the carpark still thought the shots were from there so just as hurtful haha! #Sheep

ACB__'s picture
ACB__'s picture
ACB__ Tuesday, 21 Apr 2015 at 2:59pm

Yeah I think aqua was on the southern side of the harbor.

Craig's picture
Craig's picture
Craig Tuesday, 21 Apr 2015 at 3:01pm

These spots are hardly secret, and they're the only real option for the whole Sydney population today, so always going to be busy.

stunet's picture
stunet's picture
stunet Tuesday, 21 Apr 2015 at 8:18am

Broken Bay/Hawkesbury. Be a slippery old walk with fat leeches eager to strip your ankles of blood, and then you'll arrive to be greeted by a kayaker in a freestyle rig only too happy share each wave with you.

But you'll get waves.

Craig's picture
Craig's picture
Craig Tuesday, 21 Apr 2015 at 8:55am

Hahaha, classic! I remember that morning well!

Craziest night of wind I can recall and it's stepped up a notch again. Swell is huge!

Love this shit!

oiley's picture
oiley's picture
oiley Tuesday, 21 Apr 2015 at 9:16am

unusual waves at novelty locations.. LOL... does lake illawarra count?

ACB__'s picture
ACB__'s picture
ACB__ Tuesday, 21 Apr 2015 at 10:05am

Bondi Beach skate park looking more like a snowboarder's playground. (Twitter - @busybeachnet)

Sand encroaching on Bondi's promenade after an overnight battering. (Instagram - Mark Yeats)

erikb's picture
erikb's picture
erikb Tuesday, 21 Apr 2015 at 10:11am

Wow! The last time the skatepark was that full of sand was when that ECL took out the Pacha Bulker. 2007 or whatever it was...

ACB__'s picture
ACB__'s picture
ACB__ Tuesday, 21 Apr 2015 at 10:16am

smaller scale wash up of a little boat on the central coast.

Craig's picture
Craig's picture
Craig Tuesday, 21 Apr 2015 at 10:58am

And some photos of the harbour, waves breaking everywhere, even a mysto bommie out between Middle Head and Dobroyd.

Craig's picture
Craig's picture
Craig Tuesday, 21 Apr 2015 at 12:10pm

I think satellite observations are under-cooking this ECL a little.

With land observations between 50 and 60kts, while ASCAT is only showing 45kts. (Norah Head average wind speeds have been around 50kts for the last 6 hours).

mick-free's picture
mick-free's picture
mick-free Tuesday, 21 Apr 2015 at 2:14pm

Media aren't under-cooking. The click-bait reads 1:31pm East coast cyclone smashes Sydney.

Day of the year at Balmoral

Craig's picture
Craig's picture
Craig Tuesday, 21 Apr 2015 at 5:22pm

Sydney maxing at 13.5m Max Wave Heights.. Oh and Peak Periods of 14.8s, but looks even larger on the spectra.

chad schomberg's picture
chad schomberg's picture
chad schomberg Tuesday, 21 Apr 2015 at 6:26pm

Just had 8 to 10 foot beachy tubes scary as fuck just on dark with 40 knots sw mid north coast. Ski assist was the only way

wellymon's picture
wellymon's picture
wellymon Tuesday, 21 Apr 2015 at 7:07pm

Isn't the weather such a beautiful phenomenon...
Did any one model forecasted this event;) Don, Ben, Craig ,Southey......?
I Love it this stuff.......

mick-free's picture
mick-free's picture
mick-free Tuesday, 21 Apr 2015 at 7:33pm

Where abouts Chad? - Port mac had light winds all day.

I think they did but the models didn't have it lingering again tomorrow Welly. Be on the boat with Dave if I was up there haha. get some kegs for us. We all drowning in Sydney.

dfinnecy's picture
dfinnecy's picture
dfinnecy Tuesday, 21 Apr 2015 at 8:03pm

P mac did indeed have light winds all day. Eerie to look at the surf here and know it is a different scene south.

Albertinelli's picture
Albertinelli's picture
Albertinelli Tuesday, 21 Apr 2015 at 7:56pm

My mate bob works on Sydney Ferries. Had a few great rides on Sydney Harbour today :)
Good to see lots of rain living at Camden for the last 14 years. Moved from the Northern Beaches don't regret it. Surf the south coast a lot no crowds. BIG SURF!
Because of the LOW VERY MESSY! Sit back ride my Horse wait for Thursday or Friday and hit the water with hopefully favourable winds. Monday looks OK for points facing NE Early next week Ben??

wellymon's picture
wellymon's picture
wellymon Wednesday, 22 Apr 2015 at 2:52pm

.
Yeeeewww

chad schomberg's picture
chad schomberg's picture
chad schomberg Tuesday, 21 Apr 2015 at 8:53pm

Mick- Free, Between Nelsons and Forster. Now dead calm.

mick-free's picture
mick-free's picture
mick-free Wednesday, 22 Apr 2015 at 6:56am

peak just nudged the 8m overnight with a 15m wave recorded whaaat!

Welly reminds of the flight of the concords - your a legend Dave

Wow Mid North Coast and Lennox today

stunet's picture
stunet's picture
stunet Wednesday, 22 Apr 2015 at 7:43am

Just 'surfed' the point break near me Mick. Pay good attention to the quote marks.

mick-free's picture
mick-free's picture
mick-free Wednesday, 22 Apr 2015 at 2:03pm

Banks have been murdered, just checked Narrabeen sand was looking so good last week....now up to the car park. Cleaning up by the minute though so will be a good sess tonight.

thermalben's picture
thermalben's picture
thermalben Wednesday, 22 Apr 2015 at 2:50pm

Still sets breaking at Phantoms off Shark Island.