Analysis: Cold water and green seas

Craig Brokensha picture
Craig Brokensha (Craig)
Swellnet Analysis

Regular Swellnet readers would be familiar with the yearly article explaining the phenomena behind the cold water upwelling that's most noticeable during East Coast summers.

It's a fairly simple process where persistent strong north-east winds transport the surface ocean water away from the coast. Though the wind blows towards the coast, the surface water counter-intuitively moves offshore due to the Coriolis Effect, or the spinning of the Earth on its axis.

As the warm surface water moves offshore it's replaced by deeper colder water in a process called coastal upwelling.

The phenomena is pronounced as it usually happens during bouts of hot weather weather when surfers get more than they bargained for. Keen for a refreshing session they're forced to freeze in boardies.

This cold water is usually upwelled from the continental shelf, but if the process continues for a sustained period we get even deeper colder water brought up from beyond the shelf break. When looking at Google Maps or any other map showing details of the ocean floor (bathymetry) you can identify areas where the shelf break comes close to the coast.

It's these areas that see the most pronounced upwelling events and concurrently the biggest drop in temperature.

Along the East Coast you can identify these regions as close to Jervis Bay, Narooma, Seal Rocks followed by the upper Mid North Coast and Ballina.

Upwelling is a major source of primary production, as the nutrient rich water is bought into the photic zone - where the sunlight impacts the water column - causing photosynthesis and the blooming of phytoplankton.

Phytoplankton are the base of the food chain and everything builds up from here.

Chlorophyll is needed for the photosynthesis process to take place and this is what we observe when the water starts turning that greeny colour.

The more concentrated the phytoplankton the more intense the colour but also the lower the visibility. This is why if you're a diver or spear fisherman you'd be best to avoid swimming after days of strong north-east winds on the East Coast as the visibility will likely be compromised. You may also notice in some areas the upwelling also causes corn-flake like red/brown floaties in the water.

The amazing thing is that the chlorophyll can be observed by satellite and if we look at the latest available data for the East Coast (18th December), where we've had nearly a fortnight of non-stop and at times strong north-east winds, we can see a few hot spots.

The main one is off Seal Rocks and this is one of the most productive zones for upwelling off the East Coast. Being close to the shelf break and having the coast bend away to the south-west lends the area to rapid and prolonged upwelling events.

The other is just south of Ballina from Evans Head to Yamba with the East Australian Current sitting further offshore.

Currently the sea surface temperatures (SST's) off the Mid North Coast are well below what's sitting just offshore in the East Australian Current. Steamers are a must with 18 deg water, while it's 24-25 degrees only 20-30km offshore.

For this warm water to move back in shore we need a strong southerly change and unfortunately this doesn't look to occur within the next fortnight at least across the northern NSW coast, with a brief burst of southerly winds Sunday across the southern NSW coast, bringing SST's up a touch temporarily.

Therefore we're set for a continued period of cold greeny water.

On the upside, at least the fish should be on the bite.

Comments

freeride76's picture
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freeride76 Thursday, 3 Jan 2019 at 4:07pm

Unfortunately, while theoretically that cold green water might be nutrient rich, it completely shuts down the summer pelagic fish bite.

and all the inshore summer species like whiting, flathead, etc etc.

That cold green water is a fishos nightmare.

Craig's picture
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Craig Thursday, 3 Jan 2019 at 4:10pm

Ah yes I remember you mentioning this last time. Are they sitting on the edge of this boundary then you think? Offshore where it meets the warmer clear EAC?

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tubeshooter Thursday, 3 Jan 2019 at 8:36pm

Check the thermocline levels and go from there. Pelagics are still around .

jez's picture
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jez Thursday, 3 Jan 2019 at 4:57pm

thanks Craig,
Great article.
As a spearo, i am very interested to know where i might find that satellite chlorophyll map online?

Craig's picture
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Craig Thursday, 3 Jan 2019 at 7:35pm

Here ya go Jez, click the Ocean Colour chart.. http://oceancurrent.imos.org.au/index.php

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jez Friday, 4 Jan 2019 at 7:10pm

Thanks Craig, much appreciated!

donweather's picture
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donweather Thursday, 3 Jan 2019 at 5:37pm

When on gods earth are we going to see any wind with the letter "S" in it!!!

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martymcnab Friday, 4 Jan 2019 at 4:46pm

Hey DonWeather, it's been happening for the last two weeks - "Sh*t" winds.

Gee I hate summer. Bad surf, hot humid weather. Roll on autumn!

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Roystein Thursday, 3 Jan 2019 at 6:39pm

i think you will find that chlorophyll is vital for photosynthesis to occur but is not produced during the process, but as you correctly mentioned the conditions cause an increase in phytoplankton concentration in coastal waters

Craig's picture
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Craig Thursday, 3 Jan 2019 at 7:42pm

Ah yes corrected.

The phytoplankton have chlorophyll which is used for photosynthesis. And when the nutrients are brought up from the deep the phytoplankton feed on them and increase in concentration, hence being visible from satellite.

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blindboy Thursday, 3 Jan 2019 at 8:37pm

Better green water than red tides.

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nextswell Thursday, 3 Jan 2019 at 10:24pm

Love these articles. Just north of coffs, hasn’t been a southerly wind for well over 2 weeks.

Casp's picture
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Casp Thursday, 3 Jan 2019 at 10:38pm

Hi Craig cheers for the article, I was thinking, “why the green water” in the surf this afternoon... during this surf the water had a very fishy smell about it! (like a can of sardines) is this a coincidence or would it have some sort of correlation with the Phytoplankton phenomena?

Craig's picture
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Craig Friday, 4 Jan 2019 at 7:38am

Yeah that'd be a part of it for sure, had a similar solo green water surf on the lower MNC at the end of last year, was a bit on edge and could see the baitballs at times. Feet up!

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Groper Thursday, 3 Jan 2019 at 10:41pm

Yamba surf report photo depicts it perfectly.
Start of a Fishers dream. First will come the Manta carrying Cobes!!!
We also get upwellings caused by strong currents pouring downhill past Byron that drag the inshore surface waters out.

freeride76's picture
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freeride76 Friday, 4 Jan 2019 at 7:35am

the downhill current is almost always warm blue water from the EAC.

Craig's picture
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Craig Friday, 4 Jan 2019 at 7:36am

I think he's referring to at the interface?

Groper's picture
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Groper Saturday, 5 Jan 2019 at 7:27am

Shape of the Coastline. The EAC pours past easterly point of Byron and doesn't bend back to the coast until around Coffs. As it flows down it drags the inshore waters around the Clarence Coast out which are replaced by upwelled water. Can often result in a mixture and clear green water.

lomah's picture
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lomah Friday, 4 Jan 2019 at 12:12am

Spent 3 hours in the water today on nsw south coast in boardies. Much warmer than Sydney Newcastle and mid north coast last week.

Craig's picture
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Craig Friday, 4 Jan 2019 at 7:37am

Great example and feedback. Thanks.

chook's picture
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chook Friday, 4 Jan 2019 at 11:59am

...if you do get any upwelling down that way, it is savagely cold. the continental shelf is very close to land along the narooma/bermagui/mimosa rocks stretch. (that's why it's a good place for catching marlin). coldest surf i've ever had is a summer surf at bermagui.

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Lalic Friday, 4 Jan 2019 at 7:46am

Surfed palms area last week and it was freezing (I reckon an honest 16 degrees two days) and in town the beaches were about 20. That often happens up there. Why is palms colder than Forster itself?

Now I'm down south coast just south of gerringong, and it's boardies and at least 20 degree water maybe a touch more.

Ps both coasts the water was as clear as I've ever seen it and totally pristine. No green?

Craig's picture
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Craig Friday, 4 Jan 2019 at 7:51am

Interesting, maybe fresh upwelled water that's yet to really bloom? I have had murky green water at Palms many times before, but usually it's super clear.

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cd Friday, 4 Jan 2019 at 6:44pm

Most likely an influence from Wallis Lake. The cold water hasn't yet pushed into the system. Well was still warm where I was fishing last week.
Water dark in colour now at the Palms.

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tidak_bagus Friday, 4 Jan 2019 at 7:21pm

My understanding is that cape Hawke interrupts the process and you won’t get upwelling north of the cape but south of the cape is cold. Yeah Boxing Day was warm but the day after was definitely down 16-17 degrees. Interestingly north of the cape today was warm but very green

thermalben's picture
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thermalben Friday, 4 Jan 2019 at 7:45am

Little patches of upwelling on the Tweed yesterday. Was super shallow too - duckdiving under a wave would bring an instant warmth, and then a brief colder flush as you came back through the surface layer.

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P'tai Friday, 4 Jan 2019 at 7:49am

Just been for a swim this morning at Forster, the water is cooler and has a green tinge to it, looks quite murky. Still nothing ridable tho.

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Spuddups Friday, 4 Jan 2019 at 7:54am

I was up in Northern NSW in July and the water was nice and warm. The nights and mornings were rather cold (6 deg) with S-SW winds predominating till lunchtime every day. I was wondering if this situation is the opposite of the NE wind/ cold upwelling thing, meaning that the water from the warm E.A. current is being dragged onshore by the southerly.

Craig's picture
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Craig Friday, 4 Jan 2019 at 7:57am

Yep. Southerly winds push the displaced warmer water back into the coast.

That's why when we get a strong southerly change persisting for 24 hours or more it should start bringing the warm water back in.

Also coastal eddys can enhance (when flowing with the north-east wind) or prohibit upwelling in some instances.

donweather's picture
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donweather Friday, 4 Jan 2019 at 4:16pm

And this is one reason why i want winds with the letter "S" in them to return sooner rather than later. This by far is one of the most sustained cold water spells I can recall at this time of year for a long time.

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groovie Friday, 4 Jan 2019 at 8:00am

The same high pressure system has sat in the Tasman now for well over 2 weeks, producing varying degrees of nor/nor/Easters & junky wind swell with a period of less than 7 sec. this pattern produces the Ekman effect which delivers our upwelling. It really is an early summer pattern that we haven't seen for the last few years on the east coast. Hopefully we also see strong lows develop in the Coral sea that drop into our swell window to produce some long period north swells with south winds, as we used to see in previous years after an extended period of no decent waves.

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blindboy Friday, 4 Jan 2019 at 9:31am

First week of Feb is always a good bet for a decent swell.

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Spuddups Friday, 4 Jan 2019 at 8:03am

It's a fascinating subject. It has always intrigued be how Lima Peru is so close to the equator but has such cold water.

Craig's picture
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Craig Friday, 4 Jan 2019 at 8:06am

Those who frequent the South East coast of South Australia would be familiar with wearing 4/3 streamers in the peak of summer while outside the north-east offshore is blowing 40+ degree heat in.

The upwelling off that region is very cold under strong persistent summer south-easters.

thermalben's picture
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thermalben Friday, 4 Jan 2019 at 8:20am

Was chatting to a mate about that yesterday, who's heading west in Autumn, and asked what wettie he should take.

I said "I don't think I've ever gone to the west coast and thought jeez, I wish I had only brought a vest or a springy!"

Even if it is a little warmer, you'll probably benefit from the extra sun protection anyway. So the steamer always gets packed, even if it's in the middle of summer.

Craig's picture
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Craig Friday, 4 Jan 2019 at 8:25am

Yorkes was beautiful over Christmas, probably 20deg and fine in a 2mm short-arm springy. The gulfs do warm up a lot in summer though. Port Lincoln/Coffin Bay also experiences upwelling under those same south-easterlies in summer.

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thermalben Friday, 4 Jan 2019 at 8:45am

Yeah Yorkes has the benefit of both gulfs, the northern end of which can get very warm (and saline! As you know from your Honours thesis).. but crikey I have had some cold surfs over west in summer, mainly because the upwelling tends to occur in the lee of particular (small) geographical peninsulas, that also offer good waves on their eastern side under the prevailing sou'easters.

Tuna spotters reckon that's where they see some big biteys too.

freeride76's picture
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freeride76 Friday, 4 Jan 2019 at 10:03am

We've been pretty lucky here so far, a strong EAC and eddy around Byron has kept water temps nice.

it's amazing what effect the EAC and water temps have on local wind strengths and how they can mediate synoptic wind strengths, and conversely how easily strong feedback loops from Ekman transport and subsequent cold upwellings can create increased gradient wind Nor-easters.
When that pattern locks in it can really take a fair bit to dislodge.

The other day was a classic.
Synoptic nor-east wind was blowing all night and dawn had 15-20knot nor-easters at Cape Byron.
By mid-morning, with warm water and roughly equal land/water temps the arse dropped out of the nor-easter and we got something that happens quite frequently in these types of conditions: a mid-morning "glass off".
Glass off is used loosely but conditions definitely improve.

I think Hat Head is closest to shelf on east coast Oz and that stretch from Grassy Head to Point Plomer has the most extreme cold water upwellings in my experience.
Literally seen it go from 24 to 18 overnight under strong nor-easters.

On the other hand if anyone ever wants to see the strength of the EAC in summer go up to Smokey Cape light house and look roughly due east to Fish Rock.
When the EAC is flowing it's like a buoy sitting in a really strong tidal flow.

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Paddledamnit Sunday, 6 Jan 2019 at 11:49am

Freeride, try spearfishing Fish Rock then in those conditions. My most memorable time was drift diving the rock while the EAC was in full force, and around 200m south of the rock I tried to reach the bottom in 30m of water. I dived down to around 23m and decided to return to the surface, casually. After ascending for a period of time (which felt long) I realised I was not getting to the surface and found out why. The enormous eddies behind the rock extending for hundreds of meters were sending spiralling currents downwards as also witnessed by small trapped air bubbles spiralling down. I shat myself and put the pace on for the surface and made it only thanks to my freediving fins, experience and fitness. Respect for the ocean

Craig's picture
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Craig Monday, 7 Jan 2019 at 9:52am

That's incredible and super scary. Wow.

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gcart Friday, 4 Jan 2019 at 10:57am

Great analysis Craig , any similar data available for us over here on the West - between the capes ? Given that it has been a cooler than average summer so far , with consistent S/SE wind trend , the highs seem to be coming in at more northern latitudes..

Craig's picture
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Craig Friday, 4 Jan 2019 at 1:33pm

Yep, you can access the data here: http://oceancurrent.imos.org.au/index.php

SST wise it looks cooler off the northern end of the Cape which would be a result of upwelling. 18deg or so? You can also see the warmer Leeuwin Current further offshore as well.

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joakse Friday, 4 Jan 2019 at 1:26pm

Took my pool thermometer down to the beach this morning. 16 degrees. Wowsers. I guess the positive is there are definitely less people in the surf or they're in and out for a quick hour session. Bloody cold and windy here.

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Craig Friday, 4 Jan 2019 at 1:28pm

Wow, where you located? Port region?

joakse's picture
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joakse Friday, 4 Jan 2019 at 2:02pm

Yep. Interesting as the BOM water temp shows high teens to low 20s. Not even close here and has been sitting at this temp for at least 10 days. Maybe offshore at the buoy it could be warmer. We have the trifecta...cold water, red weed and blue bottles...oh plus endless NE winds.

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Craig Friday, 4 Jan 2019 at 2:04pm

Here's 2nd of Jan!

thermalben's picture
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thermalben Friday, 4 Jan 2019 at 1:30pm

Jeez, even Vicco beaches are still 19 degrees!

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Cp Friday, 4 Jan 2019 at 6:26pm

Great read Craig. I went for a dive and a surf around gerringong yesterday. Crappy dive in the morning - next to no visibility in both shallow and deep water. Then an afternoon surf in boardies for a couple of hours in what looked like crystal clear water from above. Obviously deceiving.

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Distracted Saturday, 5 Jan 2019 at 7:17am

Craig, re the water colour. I wonder if it is also partly a seasonal factor. On the lower MNC, there are patches of weed being moved around by the wind but they don’t seem to be getting bigger and are mixed in with pools of very cold relatively clear water.
I think that the really cold green upwelling water that is filled with weed, jellies and Sea hares may occur more in spring when the upwellings coincides with rising air temp and the phytoplankton is ready to bloom. Now might be too late in the season for it to really bloom?

Groper's picture
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Groper Saturday, 5 Jan 2019 at 7:45am

Laurieton upwelling is well researched and strongly influences the coastline to the south.
Check out Trapped Coastal Waves for another interesting coastal process not only in terms of water temperature but also sea level heights. Could add up to another 50cm of water depth to a break.

thermalben's picture
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thermalben Saturday, 5 Jan 2019 at 9:14am

We’ve discussed coastal trapped waves before, not a dedicated article though it’s mentioned in the comments in this one below (which has other interesting info).

https://www.swellnet.com/news/swellnet-analysis/2016/04/19/inverse-barom...

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big wave dave Saturday, 5 Jan 2019 at 8:59am

hi Ben. I'm in South West Rocks and have noticed that these black NE'ers really crank up overnight, which is counter intuitive for me. I would have thought that the sea breeze would be strongest when the temp difference between sea and land is greatest ie early/mid arvo.
Any theories?
ps-very cool article and comments. Love that stuff...

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thermalben Saturday, 5 Jan 2019 at 9:16am

BWD, you’re under the influence of a gradient wind right now. Because of your position relative to the common migratory pattern of Tasman high pressure systems, it occurs more often in your neck of the woods than further north (though not always the case). As per the forecaster notes, the wind was expected to be up early across your region.

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Feralkook Saturday, 5 Jan 2019 at 9:31am

Reading started me thinking whether there is a correlation between these upwelling events and shark presence. Given the increase in plankton I would have expected an increase in bait fish which would encourage the predators. Then someone's comments that upwelling is a fisho nightmare put a curve ball into that one.
I really appreciate these sorts of posts as it takes me into a different realm from my other interest of severe storms.
Cheers!

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Craig Saturday, 5 Jan 2019 at 9:45am

On that note I know there was some research a couple of years ago looking at the correlation between shark interactions and attacks in regions with high chlorophyll readings, not sure if it is still going but lots of reports have been in crystal clear water.

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Distracted Saturday, 5 Jan 2019 at 9:54am

Blindboy said it was better to have green water rather than toxic red tides, however, the green water can occasionally have localised negative impacts on coastal water bodies.
When there is a Red weed bloom following the green water, sustained nor’easters can drive the weed up into shallow tidal creeks where it then dies in the shallow hot water. If there is enough it can cause a deoxygenated water event as the decomposing weed is broken down by organisms that consume all the available oxygen. This results in a localised fish kill including shellfish and yabbies.

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Lanky Dean Saturday, 5 Jan 2019 at 3:43pm

Seen this scenario first hand, man its spooky .......

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STRATTOS28 Saturday, 5 Jan 2019 at 3:35pm

Very interesting reading great article and also some more knowledge in the comments ! I surf everyday here in sydney and those severe drop in water temp really seems to always occur overnite maybe also pushed by new buidling NE windswell... all week water been beautiful and this morning it was freezing

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thermalben Saturday, 5 Jan 2019 at 4:11pm
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Craig Tuesday, 8 Jan 2019 at 1:06pm

Crowdy Head dropped to a freezing 15.25deg Saturday night.. The upwelling wasn't picked up by many of the other buoys.

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freeride76 Tuesday, 8 Jan 2019 at 2:32pm

I'd say inshore water temps in Ballina are now well below 20......maybe 18-19

Blowin's picture
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Blowin Tuesday, 8 Jan 2019 at 3:26pm

Warmer here.

Just saw a thumping bull mahi at the boat ramp. Fish everywhere. Had a noah do a u - turn a couple of metres in front of me on the paddle out this morning.

Surf was shit though , should’ve gone fishing.

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Craig Tuesday, 8 Jan 2019 at 3:26pm

Yeah southerly has brought in the warmer water back to Sydney, though still probably 20, up from the weekends 16 or so.

freeride76's picture
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freeride76 Tuesday, 8 Jan 2019 at 4:05pm

few days before Christmas I went for a midday fish on the low tide change.
10 mins later I was back at the Camry with a 10kilo jew.

2 weeks later on the same tide change I did exactly the same thing.

Got to admit that was far more exciting than any of the either slop surfs or super crowded surfs I've had during this never ending pattern of onshore winds and 3ft E swell.

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Blowin Tuesday, 8 Jan 2019 at 5:17pm

Not sure how I got there , but I was reading an old surf report you’d done fora magazine in your area and there was a photo of a nice tunny you’d caught flicking soft plastics , now it’s dialing in the Xmas Jew bite.

Happy days.

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qbctm Tuesday, 8 Jan 2019 at 3:30pm

Down at Werri a few days after Chrissy and I walked in for a surf in boardies...got up to my thighs and walked out ...bloody winter cold..must've been around 16c or less

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Craig Tuesday, 15 Jan 2019 at 2:31pm

Those surfing since last week would of noticed that the southerly change and lack of north-easters saw the warm clear water move back in, kicking back to 22-23 deg in Sydney. We'll see the upwelling kick back in over the coming days again, so don't put away the rubber just yet.

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thermalben Wednesday, 23 Jan 2019 at 6:43am

Incredible SSTs recorded at the Byron buoy over the last few days, peaking at 27.95 degrees on Sunday afternoon.
​​​​​​​

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freeride76 Wednesday, 23 Jan 2019 at 8:35am

it's been a very strong downhill run from the EAC lately.....which has also had the effect of moderating the strength of the NE flow.

Weirdly, wind velocities from the NE have been stronger at Ballina airport, only a few K inland than at the beach.

we'll see if that warm eddy is strong enough to resist upwelling over the next few days of predicted 20knot nor-easters.

Also, as has been pointed out before the Byron Waverider Buoy is in 60m of water (I think 3 or 4 nm out), due east of Ballina bar.

The water temp has no relation to inshore temps either at Byron Bay or Ballina beaches.

thermalben's picture
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thermalben Saturday, 2 Feb 2019 at 8:24am

Water temps are the Coffs Harbour buoy (orange line in the graph below) jumped from 21.2 degrees to 26.9 degrees in the space of one hour (yesterday, between 1am and 2am).

Of course this is some distance offshore and not representative of temps in the surf zone, but it's a fascinating insight as to small scale SST variability.

​​​​​​​

This was around the same time that a prolonged synoptic N'ly wind finally abated to under 10kts, preceding a gusty S'ly change (though, the northerlies did ease a few hours earlier, and the change was still six hours away). 

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Dan K Friday, 8 Feb 2019 at 5:46am

How reliable is the MHL data for sea temps? I use it quite a lot to gauge temps for chasing pelagics where I live, but this morning there's been a spike which remains fairly consistent with Coffs Harbour reaching 32 degrees! Is that even possible?
Thoughts Ben, Craig or anyone else up to speed with MHL data and current temps in general?

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thermalben Friday, 8 Feb 2019 at 5:57am

Well spotted.

Coupla of points:

1. Actual temp data should be accurate, unless there is a technical fault with the onboard thermometer. Could buoy fouling affect the accuracy of the data? I'm not sure but will have a look to see if there's any information on this.

2. As you're probably aware, most buoys are anywhere from 2-12km off the mainland, so they're usually recording SST at or near to the shelf, which is sometimes not directly related to SST in the nearshore region. 

3. A concurrent increase in SST happened at the Crowdy Head buoy (see image below), and the temp range was much bigger. Coffs Harbour jumped four degrees from from 28 to 32; Crowdy Head jumped seven degrees from 19 to 26 (!).

4. CSIRO/IMOS satellite derived data only goes up to 28 degrees. Yesterday's data shows a broad region of very warm water with several areas of 28+ degrees. I'm skeptical, but in the absence of any other information, I suppose it's plausible and can't be ruled out.


5. Gut feel is that it's not accurate, mainly because of the sustained nature of the 32 degree reading (thus far, anyway). Crowdy Head spiked to 26 degrees and then dropped back to 22 degrees within a few hours. I know this data is not quality controlled in real time, so I'll ask MHL what they think.

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Dan K Friday, 8 Feb 2019 at 6:17am

Thanks for the response Ben
I'm in Forster so my go-to is the Crowdy data (also known as the upwell coast haha!)
I saw the Crowdy spike coincided with the spike at Coffs and thought there was a chance it just might be correct - will wait to hear from what feedback you receive from MHL. Cheers

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thermalben Friday, 8 Feb 2019 at 11:19am

Alrighty! Just heard back from Mark at MHL (for reference, the data collection is funded by the NSW Office of Environment and Heritage, and managed by MHL).

"There was also a sudden jump in SST at Coffs Harbour back on 1 February from 21 to 27 degrees in one hour. The QC process identified a corrupt record around that time but the 27 degree SST was possible and tied in with the strong EAC and SST charts on the BOM’s Marine and Ocean web pages. This latest rise on 7 February from 28 to 32 degrees seems a bit extreme so we will monitor the records in more detail. Based on experience the SST sensor should not be affected greatly by fouling on the buoy and we have had only one SST sensor fail in the past although the results were very erratic from hour to hour on that occasion which clearly indicated the sensor had failed.

The Crowdy Head data seems OK. Based on the BOM’s SST charts there has been a cool pool of water along the coastline north of around Forster for the last couple of weeks and the temperatures recorded by the Crowdy buoy seem to reflect some upwelling from time to time."

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Blowin Friday, 8 Feb 2019 at 11:32am

27 degrees a few kms offshore here this morning. Current was so blue it was purple. It was also moving South so fast it was causing slight whirlpools in 55 metres of water. Saw a couple of flying fish but fuck all bait around.

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Craig Friday, 8 Feb 2019 at 11:32am

Nuts, how's the boat negotiate the currents?

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Blowin Friday, 8 Feb 2019 at 11:42am

No dramas. Feels like you’re driving uphill heading into it.

Saw a couple of fellas kayak fishing out there too. Not as wide , but still hectic enough in a plastic pool toy that sits 6 inches above the waterline. I’ve seen dorsal fins way taller than that out there.

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simba Friday, 8 Feb 2019 at 1:14pm

Purple water,yohooo,,,got to love the colour purple...........go for a drift dive out there Blowin,like being in outer space........never know what you will see.
Temps have jumped here a fair bit in close.Time to fish for mackeral.

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Blowin Friday, 8 Feb 2019 at 1:54pm

Simba - I’ve got a fair idea what I MIGHT see , that’s why I’m not in a hurry to jump over the side out there.

On my own out there anyway , so it probably won’t be happening. I’ve got my fingers crossed for a wahoo. I’ve never caught one and it’s on the bucket list. You’d have to be lucky around here , I suppose , but I know they get them every now and again.

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simba Friday, 8 Feb 2019 at 2:42pm

Mate just drift with the boat,if its as clear as i think you will have plenty of time to get back in the boat cause a 12ft tiger will look about an inch long when you see it,but obviously have someone in the boat if you can.Got any bombies rising up down there?....cause wahoo love that sort of thing.

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Craig Wednesday, 27 Feb 2019 at 4:26pm

Amazing to see the SST charts off Sydney now, with inshore temperatures a balmy 23 degrees or so, but just offshore, up to 25/26 degrees.

The Sydney MHL buoy (10km offshore) is picking up 26.2 deg.

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Blowin Wednesday, 27 Feb 2019 at 4:33pm

A mate was telling me of marlin free jumping out the back of the surf just south of Sydney recently. They also caught one a couple of kms out.

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Craig Wednesday, 27 Feb 2019 at 4:35pm

Nuts! This is what the fishos hang for isn't it, I know a few of my mates do.

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Blowin Wednesday, 27 Feb 2019 at 4:57pm

The pelagic fish - the big , free ranging top water predators- swim south in the warm current and hang on the edges / eddies where it intersects all of the food which lives in the nutrient rich colder southern waters.

They do little sorties into the colder water and smash the small baitfish who are feeding on the zooplankton disoriented by the turbulence in the meetings between the warm/ cooler waters.

So when you’re out surfing and the water changes temperature there’s all kinds of different critters hunting furiously.

Some BIG fish amongst them.

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freeride76 Wednesday, 27 Feb 2019 at 5:32pm

March is pelagic month here.
I hope this shit gurgle swell eases up so I can finally pin a spaniard off the stones.

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simba Wednesday, 27 Feb 2019 at 6:32pm

Float live baits in the river on the incoming tide.....if your allowed these days.

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gannet Wednesday, 27 Feb 2019 at 7:33pm

Crazy warm water down south in vicco

ie boardies for a short surf

wtf?

(this dont happen too often)

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Blowin Wednesday, 27 Feb 2019 at 7:51pm

I tried to put up a photo of my warm water happy place.

I failed....and now I’m not happy.

[ img ] https://ibb.co/TLfX7cj [ /img ]

[ img ]https://ibb.co/TLfX7cj[ /img ]

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stunet Wednesday, 27 Feb 2019 at 7:52pm

Fixed it for you...

Gotta right click on the image, click 'Copy Image Address' (it'll end with .png or .jpg) then do what you did wrapping it with [img] [/img].

Chin up. You'll get there.

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freeride76 Wednesday, 27 Feb 2019 at 7:53pm

I can see 'em.

re: live baits in the river, I caught a 30 pound longtail in the river a couple of Marches ago.

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Craig Wednesday, 27 Feb 2019 at 7:54pm

Very nice! Mate off North Head tonight said the current running south against the southerly wind was slamming the headland. Crazy!

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Blowin Wednesday, 27 Feb 2019 at 7:57pm

Right click ?

I’m on an iPad.

Thanks Stu.....apologies for the incompetence. Does my head in.

Freeride ...that’s a fine catch from shore. A fish off the rocks is worth three from a boat.

If you’ve got a photo ( and you’re not a fellow photo kook ) let’s see it .

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freeride76 Wednesday, 27 Feb 2019 at 8:03pm

I will see if I can drag it up, it's on a hard drive somewhere.

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simba Wednesday, 27 Feb 2019 at 8:52pm

speared big mackeral years ago over at the dolphin wall...so they go up occassionally ..also plenty of big jew that like the wreck near the coast watch tower.

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Distracted Wednesday, 27 Feb 2019 at 10:25pm

What about the story about the bloke years ago at Crescent that brained a mackerel in the creek with his yabby pump. Thats what you call an inshore pelagic

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freeride76 Thursday, 28 Feb 2019 at 12:56pm

Craig's picture
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Craig Thursday, 28 Feb 2019 at 12:58pm

Wow, today?

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freeride76 Thursday, 28 Feb 2019 at 12:59pm

March 2014

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Craig Thursday, 28 Feb 2019 at 1:00pm

Very nice. Heard the FADs are under water with the raging EAC at the moment. Beautiful, warm, crystal clear water in Manly today.

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freeride76 Thursday, 28 Feb 2019 at 1:02pm

gurgle and a bit turbid here, but bath warm.

seen lots of gar showering lately so I know the pelagics are here.

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Blowin Thursday, 28 Feb 2019 at 1:44pm

Freeride - Stoked to get that beauty. You’ve got to know what you’re doing to get a fish like that off the rocks. Hate to sound mercenary, but a fish like that’d yield 10 kg of meat @ $30/kg. That’s some quality chewing ....Fresh , free range , organic goodness. Hard to put a price on the satisfaction of targeting and landing a fish like that under your own steam.

Got out in the Sea Wok briefly this morning. Got my livies , punched out into a freshening wind then got hit by a couple of fronts which white capped the shit out of it. Looked to sea and saw the mother lode of wind/ rain coming and GTFO.

Now it’s sunny and still .....and I’m housebound again.

Oh well , water was a bit dirty but warm with plenty of bait around.

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freeride76 Thursday, 28 Feb 2019 at 2:08pm

yeah, luckily for me there was this old digger around who knew how to gaff a fish from a Rock wall.
it's a cunt of a spot to land a fish from.

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stunet Thursday, 28 Feb 2019 at 2:15pm

Stood in as a supervisor when my eldest's cub pack did an 'introduction to fishing' thing inside Wollongong Harbour. He snagged it first cast, I rigged it again, then I stuck the hook into my thumb while baiting up with an old prawn. He was never gonna get anything and I wasn't allowed to have a beer.

Fishing sucks.

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freeride76 Thursday, 28 Feb 2019 at 2:19pm

Like surfing it seems to be something you have got to learn as a kid.

I've tried to teach a couple of my mates and the results are always hilarious and embarrassing.

Don't worry Stu, I got a treble through my thumb the other day so even old stagers can fuck it up.

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Blowin Thursday, 28 Feb 2019 at 2:31pm

Fishing = The best of times, the worst of times.

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stunet Thursday, 28 Feb 2019 at 2:37pm

The old boy was a gun rock fisherman and some of my earliest memories with him are getting up in the dark to walk the track out to Flat Rock from Bulls Paddock before it was a campground or to Pimply Rock at the northern end of Boomerang. He went after taylor and drummer, I'd get the odd bream, even had my own rod, an orange Jarvis Walker, and things seemed set. Until surfing came along that is. After that I'd still get up in the dark with him but he'd take the track and I'd paddle off the beach. And while he never said anything, I always detected a sense of disdain; that he was providing for the family and I was doing nothing beneficial.

Few years back he said to me that he was disappointed that he never learnt to surf. I replied that it was disappointing, that we could've shared good surf sessions together. Then he admitted that he was disappointed that I never really learnt how to fish.

So I guess we're even.

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Blowin Thursday, 28 Feb 2019 at 2:46pm

Did your young fella show any aptitude to fish on that fateful day at Wollongong harbour ?

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stunet Thursday, 28 Feb 2019 at 3:20pm

He did. Had a good cast on him, and seemed predisposed to sitting around in the wind while occasionally squeezing rotten shellfish till the smelly gizzards ran down his fingers.

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Blowin Thursday, 28 Feb 2019 at 3:33pm

And all the while you just stared at the putrid harbour water and fantasised it was Pale ale.

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simba Thursday, 28 Feb 2019 at 3:36pm

well sounds normal to me

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Blowin Thursday, 28 Feb 2019 at 3:45pm

Agree.

For someone who reckons they’re not a fisherman, he sure sounds a lot like a fisherman.

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thermalben Thursday, 21 Mar 2019 at 5:46am

Incredible SSTs off the NSW coast right now.

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simba Thursday, 21 Mar 2019 at 6:32am

Looks nice for pelagics.......

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freeride76 Thursday, 21 Mar 2019 at 10:05am

they ain't here.

Seems they are all in the that warmer tongue further south.

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Blowin Thursday, 21 Mar 2019 at 11:45am

Tuna busting up out the back where I was surfing this morning. Water was very warm but green. Up North a bit it’s still Fiji blue. Looks amazing.

The Sea Wok will be prowling the open ocean on the morrow.....me hearties.

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freeride76 Thursday, 21 Mar 2019 at 11:52am

I've seen one single, solitary tuna greyhounding this whole summer.

I thought OMA was going to really fire things up but that didn't happen.

I think it might be a late season as we get the pelagics happening on the way north.

Hopefully.

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blindboy Thursday, 21 Mar 2019 at 12:27pm

Water temperatures were tropical on the south coast earlier in the week, slightly cooler today but still pretty warm.

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simba Thursday, 21 Mar 2019 at 2:40pm

Finally waters coming in blue here,about time,must be some wahoo about .

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blindboy Thursday, 21 Mar 2019 at 2:49pm

My son caught a beauty of the NB last week.

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Blowin Thursday, 21 Mar 2019 at 3:21pm

Wahoo ?

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truebluebasher Monday, 7 Oct 2019 at 6:14pm

EAC (Marine Science Break-thru) Please read on...

USC research is a must have companion piece to swellnet craig's EAC paper.

*More Whales were caught in nets when EAC meanders closer to coastline.
*Notable when inner edge was mixed & messy on surface (re: craig "Nutrient Rich")
*Whales surf the wind strewn souped up phytoplankton sets as a compass south.

More messy + shelf breaks up well (re: craig) stranding Whales in nets or onshore!
1st step to monitor larger Whale migrations in times of overflowing inshore EAC .

https://www.usc.edu.au/explore/usc-news-exchange/news-archive/2019/july/...

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Craig Tuesday, 8 Oct 2019 at 8:02am

Very interesting and thanks for sharing TBB.

Though in regards to upwelling, it looks like that would actually help keep them further offshore as in shore the water will be cooler, and the East Australian Current interface further east and away from the nets.

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truebluebasher Tuesday, 8 Oct 2019 at 1:12pm

Sure upwelling floods out, but any extra fuel further races shallower overflowing EAC.
Roundabout exits Whale, fights against it's own weight, caught in reverse south sweep.
Younger,older & frail have not the means & exhaust themselves trying to reunite.

Coriolis rotation rips (re: Craig) Roundabout on ramps for mother & calf to re-enter EAC
tbb is saying these roundabouts (Whole) amplify with faster wide inner overflow seasons.
Simple for Mum to jet outta town but nightmare for Gramps & Kidz @ Airport check-in.
[ WRONG WAY GO BACK ]
Note; We all see Whales surf reverse to Migration flow but never wonder why.
Do Bumped Whales simply back flow to pick up previous roundabout onramp lane?

We all think & act similar & all surf the same so why not cruise East Coast freeway likewise?
Aborigines proved outback Town roads mirror the stars.
Organic powerful EAC may eventually overpower Pacific Hwy to migrate likewise.(Too much!)

Simple rule being to surf with the traffic flow or run out of fuel...Surfjustsurfari.

Ok! So rogue theory is based purely on tbb swimming against shallow overflow rips
Anyhow! Good that science & yourself Craig are cluing in the crew on EAC...Cheers!

[ DISCLAIMER ]
tbb too often sails off course as he daydreamed of surf, thru every school test.

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truebluebasher Monday, 14 Oct 2019 at 3:00am

EAC Roundabouts (Continued)
How Whales surf through EAC river roundabouts?

EAC Low Tide smaller Roundabout centres & spins faster Clockwise at .35m/sec.
EAC Flood Tide larger Roundabout broadens to spin slower Clockwise at .25m/sec

Here's how the southbound whale surfs around a river or creek to conserve energy.
{tbb + Whale's secret bodybash'n Key}
Pod & Breach are used alternatively to both propel into & out of Roundabouts
Pod down to merge faster spin & Breach high away from fast spin cycle.
Breach up to surf the Flood cycle & Pod current to exit beneath the over spin.
Yes! Everything works in reverse, please don't tell anyone!

(Low tide or Drought) Whale surfs further offshore to centre the roundabout.
Whale pods N/E then surfs clockwise @ .35m/sec to breach S/E exit into [EAC]
Note late entry & early exit, [L] Calves need to get up to speed & stay alert.

(High Tide or Flood Tides) Whale hugs the shoreline scenic route but enters sooner.
Whale breaches N/W surfs way out > surfs in @ .25/sec to pod S/W exit [EAC]
Note a powerful long Haul.[L] Calves back flow then wide near Orca to surfline exit.

Pod of 30 Orca are currently just offshore at Ballina after Rain...(Yes! Right now)
Perfectly timed for Migration,Weather & for Calves to Loop Wide of Richmond River.
EAC Orca drive-thru!

To be honest, Study paper was about inshore Ocean speed...(tbb added the Whales!)
Really? OK...tbb was actually timing a poo trail from Sewage Plant to Surf Line-up.
Took a detour hitched a ride on Tweed Roundabout & ended up surfing Craig's EAC.
Craig & crew would rather read about EAS surfers than tbb's crappy story.(Soon!)
About that Poo Trail ...takes 3hrs off high to ebb with EAC / splashback lasts 1-2 hrs..

https://www.coastalconference.com/2011/papers2011/Zoe%20Helyer%20Full%20...

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Craig Tuesday, 5 Nov 2019 at 7:47am

Great sat images showing the drop in inshore water temp with the weekend's upwelling event.

Was a balmy 20deg or so on Friday last week, then down to 16/17deg after those strong persistent NE winds.

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Blowin Tuesday, 5 Nov 2019 at 9:07am

It’s always hard coming to terms with Life After Indo* , but it’s not made any easier to wake up to a cold , green ocean peppered by weed when you’re attempting to marshal a semblance of enthusiasm for wind swell dogshit.

*This is a legitimate syndrome which has gone unrecognised by the psychological field for too long. The soul crushing comedown as the endorphins of adventure , good waves , exotic food and cultures leeches out of the pores within hours of reentry to the sterile Western environment.

I almost find myself craving a near-miss hit and run by a tiny dark skinned bloke carrying several long lengths of bamboo on his shoulder ,as he weaves his little motorbike through traffic with plumes of durry smoke coming out of his nostrils.

Id give anything to have a little kid run to my side screaming “ hello mister “ as I stroll past with a Bintang in one hand and a beng beng in the other.

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Craig Tuesday, 5 Nov 2019 at 9:30am

Yes yes, and then after ripping apart the perfect waves from abroad, you fail to even connect a simple turn back at your local... slipping off the warm water wax adding insult to injury.

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thermalben Monday, 6 Jan 2020 at 9:14am

Some impressive upwelling-induced SST drops across Northern NSW over the last few days. Crowdy Head got down as low as 15.8°C on New Years Day (see below), whilst Byron Bay's saw a six degree difference in temp between Jan 2 (24.6°C) and Jan 5 (18.6°C).

SE Qld has seen a more variable response though. Over the last few days, the Gold Coast has dropped from around 26°C to around 21°C, whilst North Stradie and the Sunshine Coast haven't changed much at all (26-27°C).


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Blowin Monday, 6 Jan 2020 at 9:33am

Spring suit around here.

freeride76's picture
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freeride76 Monday, 6 Jan 2020 at 11:31am

18c here.

which is colder than the coldest winter temps.

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Island Bay Monday, 6 Jan 2020 at 12:48pm

Yikes! We really did time it well.

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thermalben Monday, 6 Jan 2020 at 12:04pm

Was definitely a little colder on the Tweed over the weekend, tthough not too bad. Surfed in boardies/vest Saturday (prob 20-21) but Sunday had cooled a little, maybe 19-20 (boo-hoo, I hear Vic/Sa/Tas surfers exclaim). Didn't surf Sunday but took my daughter out, wore a long arm springy.

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Max Wax Monday, 6 Jan 2020 at 6:24pm

Still wearing my 3/2 in 21 degree water, gonna need a 6/5 for next winter haha

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thermalben Monday, 27 Jan 2020 at 2:35pm

There's been a 7 degree difference in SST temps at the Byron Bay buoy in the last couple of days (20.1°C on Friday, 27.1°C yesterday).

Funnily enough, the whole temp range is fine in boardies. Suck on that, southern states.

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greyhound Monday, 27 Jan 2020 at 2:45pm

Bait grabbed
Rather groundswell over water temp any day of the week..

thermalben's picture
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thermalben Monday, 27 Jan 2020 at 3:17pm

Haha!

Funny thing is we've just had three days of E'ly groundswell up here (though winds haven't been great, so the surf's been ordinary).

But, I hears ya.

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Distracted Tuesday, 28 Jan 2020 at 7:15am

All mixed up on the MNC, was in the steamer Saturday, boardies Sunday and springy yesterday.

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blowfly Tuesday, 18 Aug 2020 at 2:03pm

Water temp here today was 16 according to various sources but felt colder. Still in a fully lined 3/2 with heat tech vest and helmet. Very comfortable for 90 minutes or so, as long as the wind chill isn't too great.

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Craig Tuesday, 18 Aug 2020 at 2:05pm

Sydney was chilly last week but has jumped a couple of degrees the last couple of days. Feels warm in a 4/3.

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blowfly Tuesday, 18 Aug 2020 at 2:56pm

I've got a 4/3 but haven't used it much. It's handy for sitting around on inconsistent days or in crowds but my game plan at the moment is to find an uncrowded spot, stay in pretty much constant motion and get in before the calf cramps hit, though I might have solved that problem with a new leg workout.

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Craig Monday, 2 Dec 2024 at 11:13am

Quite a distinct coastal upwelling signature down the NSW coast at the moment with most places coming in cool and green.

Thanks to the colder water and humid air, most locations are also seeing episodes of coastal fog/mist..

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southernraw Monday, 2 Dec 2024 at 1:12pm

Epic read. Lots learnt.
Cheers Craig.

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southernraw Monday, 2 Dec 2024 at 1:14pm

btw i saw this morning sea water temps off the tropical north west of Australia are topping out at 32degrees celcius!

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Craig Monday, 2 Dec 2024 at 2:39pm

Yep, that's what's feeding these north-west cloud bands that are drifting in across Australia.

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udo Monday, 2 Dec 2024 at 1:41pm

Around 12 :30 mins for Sea Temps / Its a Fantastic utube page

?si=zs-xmwJdoRtshVTJ

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Halfscousehalfc... Tuesday, 3 Dec 2024 at 7:31am

Southerly coming next week? Bring the 20 plus degree water back