From west to east, the stage is set

Craig Brokensha (Craig)
Swellnet Analysis

As the run of fun surf continues across the East Coast, keen weather watchers may have noticed some juicier developments in next week's forecast.

Apart from a couple of larger southerly swells, since May we've mostly seen small to moderate-sized events from the south and east, along with favourable winds. Next week's swell, however, looks to be more significant.

When looking at these scenarios on the long-term charts, we usually have to take them with a grain of salt, yet in this case there's reason to be more confident as the pre-cursor to the event is already moving across Australia.

More observant weather watchers may have picked up the initial source of this activity. That being, a strong mid-latitude low that formed just west of the Margaret River region last weekend.

Strong mid-latitude low pushing across Western Australia yesterday (the pre-cursor)

The low brought strong to gale-force onshore winds, decent rainfall totals, and a stormy swell to SW WA yesterday, and it's currently clearing slowly to the east in a weakened form. The remnants of said low are now sitting just west of the Bight and it's the developments through today that will likely provide the catalyst for the weather system in the Tasman Sea next week.

A couple of shots of cold, polar air will be advected from the Southern Ocean, up and into the backside of the weaker low today and tomorrow. The cold air will then be transported slowly east-northeast across South Australia, Victoria, and then New South Wales later this week and through the weekend.

This upper cold pool will likely become separated and cut-off from the general zonal flow of cold air, meandering across New South Wales before finally moving offshore early next week.

At the surface level, the remnants of the aforementioned low at the beginning of the article will also drift east and move off the southern NSW coast as a trough. With an infeed of moist north-easterly winds from the Coral Sea and upper cold pool to feed off, the likelihood of a significant low pressure system is very high.

The only real questions are, where will it form and how strong will it be. The models are struggling to pick this at the moment, and the location will dictate the quality and local conditions when the developing south-east energy starts to muscle up.

The closer to the coast the low forms, the more rainfall and damaging the winds and swell will be, while a more distant Tasman Low will spare the coast mostly of significant ran but deliver a wider-ranging swell event.

What we can count on is that any low that develops will likely linger instead of being shunted off to the east. This is due to an upper level ridge (opposite to the Long Wave Trough) sitting across the Tasman Sea. The ridge will effectively cradle the low, helping to prolong the swell event and even nurture a cluster of events. This will have to be watched closely over the coming week and in the Forecaster Notes.

Sitting west of the upper level ridge will be a significant node of the Long Wave Trough, focussed across Western Australia and this in turn will bring a fresh dose of extra-large and windy surf to that region.

GFS Filtered 500hPa (Long Wave Trough) forecast for next Tuesday evening

Check in Monday, Wednesday, and Friday for the updated Forecaster Notes over the coming fortnight, with greater detail provided on the coming swell events and local winds.

Comments

redsands Tuesday, 7 Jul 2020 at 03:33 pm new

Here's one who's been watching. Fingers crossed the winds play their part.

barry-banchong Thursday, 9 Jul 2020 at 04:45 pm new

It will be intresting to see where it plants itself. red sands that's a sick wave

Sprout Tuesday, 7 Jul 2020 at 04:38 pm new

Advected, nice.

Thegrowingtrend.com Tuesday, 7 Jul 2020 at 04:49 pm new

Eureka

Walk around G Tuesday, 7 Jul 2020 at 05:23 pm new

So this is the real reason that they shut the bloody NSW /Vicco boarder, Craig ;) No southern (Mexican) invasion for this swell event.....which would have definitely been on my radar, as we're having a pretty poor winter, swell wise, around here. Correct me if I'm wrong but sure feels like a shitty la nina Winter season too me?

Bwilsk Saturday, 11 Jul 2020 at 10:32 pm new

May was pretty good

Yendor Tuesday, 7 Jul 2020 at 05:59 pm new

Interesting Craig, I always thought the long wave trough acted by shepherding most of the lows up through the nodes. However, in this case the low will form right where the node is not.

Craig Tuesday, 7 Jul 2020 at 06:08 pm new

The Long Wave Trough steers and strengthens frontal systems and the westerly storm track in general. What this upper ridge will do is allow the low to linger in the area with the lack of upper steering winds to move it away.

Yendor Tuesday, 7 Jul 2020 at 06:45 pm new

Thanks Craig, your articles have been super helpful to improve my swell forecasting and general understanding of the processes at work.
I regularly check this site https://wzn-staging.weatherzone.com.au/models/?lt=hemisphere&lc=sh&mt=g… to follow the long wave trough now. It makes a massive difference when we have a node for swells on the NZ east coast.

Craig Tuesday, 7 Jul 2020 at 07:46 pm new

Cheers! And here's an even better link showing the overview. To find it under Radar and Maps >> Polar Charts.

https://www.weatherzone.com.au/models/?lt=hemisphere&lc=sh

bluediamond Tuesday, 7 Jul 2020 at 08:34 pm new

Roger that from on the ground in WA's South. The weather is and has been absolute shite.

Remigogo Wednesday, 8 Jul 2020 at 06:21 am new

Me too and a small crew have been in storm damage repair mode last 6 or so weeks. 60 percent product loss. Each storm hits another clean up begins... haven't seen anything like this in my 4 years here.

Very interesting storm tracks atm. Great write up Craig.

freeride76 Wednesday, 8 Jul 2020 at 08:58 am new

Brave man calling it so early Craig.

even with all the ducks lined up we could still get short-changed by the surfing priest.

just a mild point, biggest swell of the autumn was the final pulse of the South/East combo swell of weekend 23/24 May. That was 6ft all weekend.

Monday 25 May was a solid and clean 8-10ft through the morning into lunchtime.

Craig Wednesday, 8 Jul 2020 at 09:03 am new

Ah, yes the wording has it appearing that May was mostly small-moderate. What I meant to say is there were a couple of large events, those you've spoken about which included the one I swam with the camera at the local with KS, but otherwise it's been mostly small-moderate in size.

goofyfoot Wednesday, 8 Jul 2020 at 10:11 am new

Craig this doesn’t mean much for Victoria does it?

Nick Bone Wednesday, 8 Jul 2020 at 12:21 pm new

Check next week. Ill take that over any kind of Winter shit

Tim Bonython Wednesday, 8 Jul 2020 at 11:03 am new

OMG! This looks serious! FROTHING BIG TIME!

langers00 Wednesday, 8 Jul 2020 at 12:46 pm new

Kudos on the long range forecast Craig. As early as 2nd July (second last paragraph) of your ‘Looking back on a great run of surf’ article you predicted this east energy.

Craig Wednesday, 8 Jul 2020 at 12:47 pm new

Thanks, and kudos to you for remembering that statement :)

Spuddups Wednesday, 8 Jul 2020 at 02:32 pm new

The two models I use both seem to agree on a pretty strong Tasman low. It’s amazing how quickly it sets up. Looks like it could be a good one if it comes true. Too bad I’m on the wrong side of the Tasman for this one. Oh well, hope you guys score.

Yendor Tuesday, 14 Jul 2020 at 08:53 am new

Aah Spuddups, from what I can see we are looking at s pretty awesome set up for our west coast. The models are showing some pretty good stable fetch aimed back our way and offshores all week.
Not the same size and power as Oz but pretty nice nonetheless.

Yendor Tuesday, 14 Jul 2020 at 08:54 am new

Get the froth train running!

Spuddups Tuesday, 14 Jul 2020 at 09:39 am new

Yep, I’d noticed that. The chances of a NW swell have certainly improved over the last couple of days. I’ve got the cappuccino machine warmed up and ready to go. Maximum froth setting.

donweather Wednesday, 8 Jul 2020 at 08:00 pm new

With that high out near NZ, this low can stay south of us for as long as it wants!!!

greg-n.williams Thursday, 9 Jul 2020 at 05:27 am new

Just happen to be travelling from the Mid nth Coast to southern QLD nxt week. Experienced a similar set up 2 years ago on a road trip to QLD. That was epic scoring 5 days @ an unnamed QLD point which pumped. Fingers crossed for another blessing from Huey!

Spuddups Thursday, 9 Jul 2020 at 06:56 am new

Fark, I just looked at the latest prognosis for that low and it looks like you guys are in for a solid week of swell and then some. It just keeps churning away.

Craig Thursday, 9 Jul 2020 at 05:47 pm new

Some good agreement regarding the timing of when things start to get serious across the southern NSW coast. Looks like we'll see winds really start to ramp up Monday afternoon though more so into the evening (in Sydney).

https://i.imgur.com/B2gNswE.jpg

EC has the initial low being less 'dipped' and with that additional infeed of E/SE winds along its southern flank. GFS has it more 'dipped'.

Secondary developments as it broadens and opens up the whole East Coast to swell later week are in agreement, though EC looks more robust..

EC
https://i.imgur.com/8uXLKQj.png

GFS
https://i.imgur.com/E4B7Rij.png

freeride76 Thursday, 9 Jul 2020 at 06:09 pm new

yeah, GFS looks more of a southern NSW producer, EC, the whole NSW coast lights up.

science Thursday, 9 Jul 2020 at 06:25 pm new

F%#k yes this is why I come here.

South Stockton should be spared given the tide height and swell direction but then again, 20ft is 20ft.... Oh I do hope this eventuates, the current state of the world bores me.

Westofthelake Thursday, 9 Jul 2020 at 06:30 pm new

Some mighty solid fetch there.

Looks like a bit of a monster really.

Sea surface also showing a bit of a warm patch

seasurfacetemp-for-140720

Craig Thursday, 9 Jul 2020 at 07:20 pm new

Yes, WOTL.

I was going to add the anomalies..

Right where the low will deepen.

https://i.imgur.com/gKwM3Lm.png

Westofthelake Thursday, 9 Jul 2020 at 07:34 pm new

Never doubted you for a second Craig :)

Love ya work.

jasonshipway Thursday, 9 Jul 2020 at 08:50 pm new

Craig, I read every day but don’t comment much. This might be one of the best long range calls ever! Well done mate. The froth is real.

tiger Thursday, 9 Jul 2020 at 10:00 pm new

Latest GFS run will do just nicely thanks!

greg-n.williams Friday, 10 Jul 2020 at 05:26 am new

Long right point breaks here we go! Winds look GR8 to hey Craig for sou/ east QLD & far Nth Coast. What day will be HUGE mate ( Wednesday is the call from what I've looked @)?

batfink Saturday, 11 Jul 2020 at 02:50 pm new

Great stuff Craig.

Hoping there’s a bit of distance between the coast and the low, a little rain is fine but 3 days of horizontal south east downpours is not great for anyone.

Water has been so clean lately too. That’ll be a while to get back.

Another plus, the sand has been building up rather quickly at beaches I’m visiting, will be good for beaches I visit to be stripped back again.

Roystein Saturday, 11 Jul 2020 at 06:58 pm new

Access has it looking like a top quality surf system from eden to Fraser currently, especially later

branda Saturday, 11 Jul 2020 at 07:30 pm new

35 years of hard labour, bought a van to travel,and now locked in sicktoria faaarrrkkkkk.

Bwilsk Saturday, 11 Jul 2020 at 10:46 pm new

This made me laugh out loud

Yendor Tuesday, 14 Jul 2020 at 08:58 am new

I truly feel for you. Hopefully you'll be rewarded with some epic swells soon.

boxright Monday, 13 Jul 2020 at 04:38 pm new

Sometimes it doesn't pay to find out about these events a week in advance. Today I've done nothing but refresh WAMs and weather pages and it's still only 2ft out the front.

Craig Monday, 13 Jul 2020 at 05:09 pm new

Ha, patience. This is a marathon not a sprint.

Craig Tuesday, 14 Jul 2020 at 10:09 am new

And we have rotation..

Craig Tuesday, 21 Jul 2020 at 08:08 am new

Did someone say cluster?