From west to east, the stage is set

Craig Brokensha
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's picture
redsands's picture
redsands commented Tuesday, 7 Jul 2020 at 3:33pm

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

barry-banchong's picture
barry-banchong's picture
barry-banchong commented Thursday, 9 Jul 2020 at 4:45pm

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

Sprout's picture
Sprout's picture
Sprout commented Tuesday, 7 Jul 2020 at 4:38pm

Advected, nice.

Thegrowingtrend.com's picture
Thegrowingtrend.com's picture
Thegrowingtrend.com commented Tuesday, 7 Jul 2020 at 4:49pm

Eureka

Nicko

Walk around G's picture
Walk around G's picture
Walk around G commented Tuesday, 7 Jul 2020 at 5:23pm

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's picture
Bwilsk's picture
Bwilsk commented Saturday, 11 Jul 2020 at 10:32pm

May was pretty good

Yendor's picture
Yendor's picture
Yendor commented Tuesday, 7 Jul 2020 at 5:59pm

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's picture
Craig's picture
Craig commented Tuesday, 7 Jul 2020 at 6:08pm

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's picture
Yendor's picture
Yendor commented Tuesday, 7 Jul 2020 at 6:45pm

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=gf... 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's picture
Craig's picture
Craig commented Tuesday, 7 Jul 2020 at 7:46pm

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's picture
bluediamond's picture
bluediamond commented Tuesday, 7 Jul 2020 at 8:34pm

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

Remigogo's picture
Remigogo's picture
Remigogo commented Wednesday, 8 Jul 2020 at 6:21am

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's picture
freeride76's picture
freeride76 commented Wednesday, 8 Jul 2020 at 8:58am

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's picture
Craig's picture
Craig commented Wednesday, 8 Jul 2020 at 9:03am

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's picture
goofyfoot's picture
goofyfoot commented Wednesday, 8 Jul 2020 at 10:11am

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

Nick Bone's picture
Nick Bone's picture
Nick Bone commented Wednesday, 8 Jul 2020 at 12:21pm

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

I am the bone

Tim Bonython's picture
Tim Bonython's picture
Tim Bonython commented Wednesday, 8 Jul 2020 at 11:03am

OMG! This looks serious! FROTHING BIG TIME!

langers00's picture
langers00's picture
langers00 commented Wednesday, 8 Jul 2020 at 12:46pm

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's picture
Craig's picture
Craig commented Wednesday, 8 Jul 2020 at 12:47pm

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

Spuddups's picture
Spuddups's picture
Spuddups commented Wednesday, 8 Jul 2020 at 2:32pm

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's picture
Yendor's picture
Yendor commented Tuesday, 14 Jul 2020 at 8:53am

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's picture
Yendor's picture
Yendor commented Tuesday, 14 Jul 2020 at 8:54am

Get the froth train running!

Spuddups's picture
Spuddups's picture
Spuddups commented Tuesday, 14 Jul 2020 at 9:39am

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's picture
donweather's picture
donweather commented Wednesday, 8 Jul 2020 at 8:00pm

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

greg-n.williams's picture
greg-n.williams's picture
greg-n.williams commented Thursday, 9 Jul 2020 at 5:27am

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's picture
Spuddups's picture
Spuddups commented Thursday, 9 Jul 2020 at 6:56am

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's picture
Craig's picture
Craig commented Thursday, 9 Jul 2020 at 5:47pm

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).

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

GFS

freeride76's picture
freeride76's picture
freeride76 commented Thursday, 9 Jul 2020 at 6:09pm

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

science's picture
science's picture
science commented Thursday, 9 Jul 2020 at 6:25pm

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's picture
Westofthelake's picture
Westofthelake commented Thursday, 9 Jul 2020 at 6:30pm

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's picture
Craig's picture
Craig commented Thursday, 9 Jul 2020 at 7:20pm

Yes, WOTL.

I was going to add the anomalies..

Right where the low will deepen.

Westofthelake's picture
Westofthelake's picture
Westofthelake commented Thursday, 9 Jul 2020 at 7:34pm

Never doubted you for a second Craig :)

Love ya work.

jasonshipway's picture
jasonshipway's picture
jasonshipway commented Thursday, 9 Jul 2020 at 8:50pm

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's picture
tiger's picture
tiger commented Thursday, 9 Jul 2020 at 10:00pm

Latest GFS run will do just nicely thanks!

greg-n.williams's picture
greg-n.williams's picture
greg-n.williams commented Friday, 10 Jul 2020 at 5:26am

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's picture
batfink's picture
batfink commented Saturday, 11 Jul 2020 at 2:50pm

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's picture
Roystein's picture
Roystein commented Saturday, 11 Jul 2020 at 6:58pm

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

branda's picture
branda's picture
branda commented Saturday, 11 Jul 2020 at 7:30pm

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

Bwilsk's picture
Bwilsk's picture
Bwilsk commented Saturday, 11 Jul 2020 at 10:46pm

This made me laugh out loud

Yendor's picture
Yendor's picture
Yendor commented Tuesday, 14 Jul 2020 at 8:58am

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

boxright's picture
boxright's picture
boxright commented Monday, 13 Jul 2020 at 4:38pm

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's picture
Craig's picture
Craig commented Monday, 13 Jul 2020 at 5:09pm

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

Craig's picture
Craig's picture
Craig commented Tuesday, 14 Jul 2020 at 10:09am

And we have rotation..

Craig's picture
Craig's picture
Craig commented Tuesday, 21 Jul 2020 at 8:08am

Did someone say cluster?