Large, windy surf ahead, XL on the weekend

Craig Brokensha picture
Craig Brokensha (Craig)

Western Australia Surf Forecast by Craig Brokensha (issued Monday July 24th)

Best Days: Selected spots tomorrow, Perth and Mandurah Thursday and Friday mornings, Monday everywhere next week

Features of the Forecast (tl;dr)

  • Large, reinforcing W/SW groundswell for tomorrow with strong N/NE tending N/NW winds in the South West (N/NE all day in metro regions)
  • Small N'ly windswell for tomorrow, fading Wed
  • Large, average mix of swells Wed with strong S/SW tending SW winds
  • Easing mix of average swells Thu with lingering S/SW winds (S/SE-SE early Perth and Mandurah)
  • Smaller Fri with strong NW winds (NE early Perth and Mandurah)
  • Oversized mix of swells building Sat with an XL swell for Sun
  • Strong but easing SW winds Sat, strong W'ly Sun
  • Easing surf Mon with variable tending locally offshore winds

Recap

Variable winds and a large, easing swell on Saturday provided improving waves across the South West, best yesterday with clean conditions and a little less size to 4-6ft.

Perth and Mandurah offered great waves with clean conditions and 3ft surf on Saturday, back to 2-3ft yesterday (smaller Perth).

A large new W/SW groundswell arrived later yesterday and was offering strong 8ft+ sets across the South West this morning with early clean conditions, 3ft across Mandurah and 2-3ft in Perth. Winds are now strengthening from the N'th limiting options.

This week and weekend (Jul 25 - 30)

Tomorrow looks generally average unless you can find some northerly protection with a strong, early N/NE breeze due to swing N/NW in the South West, while holding from the N/NE all day to the north.

A large mix of reinforcing W/SW groundswell from the backside of the complex low linked to today's swell along with N'ly windswell will create less than ideal surf. Try beachy options in metro locations.

The weather system linked to the strengthening northerly winds now looks to be just a trough, bringing no considerable increase in size on Wednesday, with it due to move east bringing strong S/SW winds that will shift SW through the day.

Thursday will remain average in the South West with lingering S/SW winds (S/SE-SE early in Perth and Mandurah) but with easing sets 2-3ft sets.

Friday looks smaller and with light, early NE winds across Perth and Mandurah, shifting NW and strengthening. In the South West winds will remain onshore all day from the NW.

Now, this strengthening NW breeze will be linked to a significant Southern Ocean frontal progression firing up to our south-west of us on Thursday.

An initial, tight low will generate a severe-gale to storm-force fetch of W/SW winds, followed by a front quickly piggy backing up on the back, generating an additional fetch of W/SW gales.

Following this, a third front will generate a fetch of gale to severe-gale SW winds, producing an extra-large pulse of swell for Sunday.

Back to the initial low/front, and this should produce an oversized SW groundswell for Saturday, building to 12-15ft in the South West, 3-5ft across Mandurah and 3-4ft in Perth but with strong but easing SW winds.

Sunday will see strong W'ly winds kick back in with the swell kicking to a larger 15ft+, 4-5ft and 4ft respectively.

At this stage, the best window for the South West looks to be next Monday when winds ease in between fronts and go light offshore. We'll have a closer look at this on Wednesday but we'll be seeing, easing 12ft surf, with 4ft waves in Mandurah and 3ft to possibly 4ft across Perth.

Comments

hayesb01's picture
hayesb01's picture
hayesb01 Wednesday, 26 Jul 2023 at 8:25am

Is this the worst winter we have had I awhile, every swell has come with weather and only little windows of sea sick offshores.. Then the none of the weather has been big enough to break up the beaches to form any banks. It feels like it's been slim pickings

Craig's picture
Craig's picture
Craig Wednesday, 26 Jul 2023 at 8:45am

Yeah it's been relentless eh, not ideal at all!

Vitchman's picture
Vitchman's picture
Vitchman Thursday, 27 Jul 2023 at 9:19am

craig, what needs to change to push the systems further south out of our wind window?

Craig's picture
Craig's picture
Craig Thursday, 27 Jul 2023 at 9:49am

Unfortunately I don't have the answer to this Vitchman, Wish I did.

thermalben's picture
thermalben's picture
thermalben Thursday, 27 Jul 2023 at 11:15am

Well, a positive SAM would help - but what's the driver of that? We're unsure.

Craig's picture
Craig's picture
Craig Thursday, 27 Jul 2023 at 11:26am

It's gone + that's the problem, where SAM impacts is very random across Indian Ocean/ Australian region.

The SAM is driven by the Amundsen Sea Low.

thermalben's picture
thermalben's picture
thermalben Thursday, 27 Jul 2023 at 11:30am

Shit! I should have checked. I just assumed persistent frontal passages = negative SAM.

southernraw's picture
southernraw's picture
southernraw Thursday, 27 Jul 2023 at 11:45am

I'll take a positive SAM over a negative Nelly any day of the week.
Hey any info i could get on historical swell data for WA and if possible the whole Southern half of oz?(free if possible). Need specific dates, preferably within the last 15 years.
Was down at the whale stranding yesterday and have been thinking of some possible causes.
Cheers fellas.

thermalben's picture
thermalben's picture
thermalben Thursday, 27 Jul 2023 at 11:45am

Not available at the moment, but will be later this year.

southernraw's picture
southernraw's picture
southernraw Thursday, 27 Jul 2023 at 12:03pm

Ahh bugger. But that's great to hear looking forward.
cheers Ben

basesix's picture
basesix's picture
basesix Thursday, 27 Jul 2023 at 12:26pm

is that what you're working on research-wise SR?
I've wondered if it's group natural-selection.. (so much of what led whales to evolve into what they have become was to escape cold-blooded predators). If a pod is being pegged by a gang of predators, would it be a species-wide evolutionary behavior to take their particular pod out of the deep-water food chain? Or same, if a disease is taking hold of a particular pod.

But who knows.. it could just be ennui.. Imagine if a despondent Inuit drifted themselves out to sea on a little ice floe, and a gang of local dolphins kept pushing them back onto land, hoping they'd give it another go.

southernraw's picture
southernraw's picture
southernraw Thursday, 27 Jul 2023 at 12:29pm

yeah it is Basesix.
More questions than answers at moment, and everyone has a theory but nothing is backed by actual evidence, which makes everything pure speculation.
Would be good to be able to start a bit of a process of elimination of certain factors to see what we're left with, hence in need of some hard data.
Yeah sure, might wanna leave the little inuit but i'm sure he'd appreciate the gestures of kindness and nurturing on his last moments.

basesix's picture
basesix's picture
basesix Thursday, 27 Jul 2023 at 12:36pm

I think the little inuit might ; )
great idea re process, hope you get hold of some helpful records.

southernraw's picture
southernraw's picture
southernraw Thursday, 27 Jul 2023 at 1:03pm

Cheers mate!

uncle_leroy's picture
uncle_leroy's picture
uncle_leroy Thursday, 27 Jul 2023 at 10:00pm

What’s your theory related to swell SouthernRaw?
Of the hundreds of Km’s of coastline, interesting they chose a sheltered bay to beach.

southernraw's picture
southernraw's picture
southernraw Thursday, 27 Jul 2023 at 10:28pm

Hey U.L. Yep and not only a sheltered bay, but they chose the most prime picnic and accessibility spot to set up a coordinated rescue mission. It was literally right in front of the grassy reserve. Tailor made for a whale rescue almost. Barbecue sizzling, tv crews parked on the grass, toilet block at hand. Couldn't have pinpointed a more appropriate spot along this whole southern coast, especially for the disposal of the dead ones by truck.
Re. the swell theory, i'll do some research and discuss it further down the track but it's basically based around the fact they're largely a deep ocean species that don't spend much time in nearshore water. Whatever drove them in was possibly something that threw their inherent mapping system out.
Like i said, process of elimination of factors. For all i know there could be seismic blasting happening out there and that drove them in. Could just be one of the mysteries of the universe we're not meant to know but gonna have a dig anyway. Was a horrible scene down there yesterday that i'll never forget. Felt pretty helpless down there so feel obliged to at least try to understand.

Jamyardy's picture
Jamyardy's picture
Jamyardy Friday, 28 Jul 2023 at 9:15am

Good efforts there SR.

UWA put a buoy down Albany (Torbay) in 2018, and then a few more around, and more recently a few between the capes (the later are in sheltered bays, so not much use to surfers). They also have a couple of drifters SE of Africa. Free current data and history is available for download https://wawaves.org/

The WA DOT Bremer Bay buoy can give you info for the last 3 days (so too with Esperance and Cape Naturaliste), and the SA and TAS buoys also the last 3 days. Albany buoy went missing a few months ago. Whole southern half of oz ! Pt Nepean buoy in Vicco appears to only provide last 24hrs, and the NSW buoys go back about a week with publicly available history.
Some ports have their own buoys, but not sure how far history goes or how valuable that info would be as they are usually in protected harbours.
All the best.

southernraw's picture
southernraw's picture
southernraw Friday, 28 Jul 2023 at 4:32pm

Thanks so much Jamyardy!! That's some priceless info and definitely helps.
Yeah that poor Albany buoy had a hard life hey. Hopefully they get another one out there soon.
Cheers and all the best.