Ningaloo Niño: The Little Boy From The West

Craig Brokensha picture
Craig Brokensha (Craig)
Swellnet Analysis

The Leeuwin Current is running a fever, with sea surface temperatures off the Western Australian coast currently significantly higher than normal.

It’s been sitting over marine heatwave thresholds for weeks, likely impacting the state's marine ecosystems.

Satellite observations of the sea surface temperature anomalies - which measure the difference above or below the long-term average - across the Indian Ocean basin reveal the warmer-than-normal sea surface temperature signature off Western Australia, hugging the coast from Port Hedland all the way down to Margaret River.

Sea surface temperature anomalies for the Indian Ocean as of 9th February (NOAA)

Anomalies are mostly sitting at 2-3°C above normal but there are vast areas pushing over 4°C above normal.

What’s also visible is a cooling signature south of Indonesia and this is thanks to dual tropical cyclones moving slowly through the region. Those being Severe Tropical Cyclone Vince and Tropical Cyclone Taliah.

The drivers behind the recent warming are a double whammy of stronger-than-normal easterly trade-winds in the Pacific Ocean and stronger-than-normal north-westerly winds off the Sumatran coast.

You may wonder how wind in the Pacific basin can affect sea surface temperatures in the Indian basin, but this example provides a good illustration of how the world's oceans are interconnected.

Those stronger-than-normal easterly winds in the Pacific Ocean - which also caused our late arriving quasi La Niña - created cold water upwelling in the central Pacific while also piling up warm water in the western Pacific.

By way of the Indonesian Throughflow - a north/south current that runs through the straits between the Indonesian islands - the warm water in the western Pacific made its way down through Indonesia, into the Timor Sea and onwards into the Indian Ocean where it influenced local sea surface temperatures.

Meanwhile, stronger than normal north-west winds off Sumatra - with no obvious connection to the Pacific winds - pumped additional warmer-than-normal water in from the north while. Localised north-east wind anomalies also suppressed upwelling off the Western Australian coast.

Wind anomaly from December 1st last year through 8th of February (NOAA)

The North West continental shelf sits right at this convergence zone and has been showing higher-than-normal sea surface temperatures for over three months now. As a result the Leeuwin Current is enhanced, transporting the warmer right down the Western Australian coast, extending all the way around the capes.

While great for surfers this marine heatwave setup has been given a name, that being the Ninglaoo Niño, with it linked to La Niña years thanks to the enhanced Indonesian Throughflow.

Similar to the Pacific phenomena, cooler events are classified as Ningaloo Niña’s and relate to cooler, upwelling events off the Western Australian Coast.

The Ningaloo Niño has a wide influence on the regional climate and ocean biodiversity, with it being detrimental to local fisheries and sensitive coral reef species. On the plus side it brings increased rainfall and moisture to the otherwise arid north-west as we’ve seen the past two months.

The below chart shows the north-west of Western Australia has seen above to very much above average rainfall over the past two months.

For surfers, the warm temperatures should persist into autumn before starting to dissipate into winter.

Rainfall deciles for the period December through January (BOM)

Comments

Clivus Multrum's picture
Clivus Multrum's picture
Clivus Multrum Thursday, 13 Feb 2025 at 11:06am

Thanks, Craig. It’s definitely felt warm!

dawnperiscope's picture
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dawnperiscope Thursday, 13 Feb 2025 at 11:25am

Interesting! amazing how much water must pump through those indo straits.

smokeydogg's picture
smokeydogg's picture
smokeydogg Thursday, 13 Feb 2025 at 11:46am

Warm water and consistent summer swells - perfect, just need some all day offshores to top it off !

Craig's picture
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Craig Thursday, 13 Feb 2025 at 2:08pm

And right now, Severe Tropical Cyclone Zelia is feeding off the warm water, progged to reach Category 5 while making landfall just west of Port Hedland!

How's the satellite imagery and cloud band connecting down to Victoria..

I focus's picture
I focus's picture
I focus Thursday, 13 Feb 2025 at 2:24pm

Been thinking that its been a bit warmer around Mandurah but we often sit in a little void here.

Rubicon's picture
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Rubicon Friday, 14 Feb 2025 at 12:29pm

Summed up Mandurah beautifully!

matt.rogers's picture
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matt.rogers Thursday, 13 Feb 2025 at 3:13pm

Thanks Craig!
With all the extra warm water sitting off the north coast, is that likely to mean more tropical lows getting around?
Wouldn't mind a few systems sending some N swells down this way...

southernraw's picture
southernraw's picture
southernraw Thursday, 13 Feb 2025 at 3:24pm

We definitely have the coolest named Nino/Na than over East.
Yep that cyclone intensifying at warped speed.
Guessing because of its slow moving and the extra warm water.
Something else a bit trippy is the current cyclone that headed West from the NW coast about a week ago, and is currently sending swell to Madagascar and Mozambique, is currently forecast to do a big loop back and head down below the SW corner and send a pretty major swell in this way, if the forecast holds. Amazing how many coasts these things can light up.

Craig's picture
Craig's picture
Craig Thursday, 13 Feb 2025 at 3:24pm

And also a deep mixed layer. That's one of the signatures of the Ningaloo Niño, it deepens the thermocline quite substantially.

southernraw's picture
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southernraw Thursday, 13 Feb 2025 at 3:38pm

Ahhh thanks Craig.
The master.
You've left me scratching for my dictionary. :-P

soggydog's picture
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soggydog Thursday, 13 Feb 2025 at 4:36pm

Have you noticed that the water is significantly warmer around the GS this summer SR, I have 22 degrees on the sounder in King George Sound, no KG’s being caught and too warm for squid.
Cracking East Swell on Sunday, Monday. Dodged the crowds and scored. Get amongst it SR?

Thanks Craig. Thermocline……definitely gotta look that one up.

southernraw's picture
southernraw's picture
southernraw Thursday, 13 Feb 2025 at 11:29pm

Hiya Soggy.
Haven't noticed significantly warmer, but it's been a sustained upper limit of our normal summer warm water for a longer period. Started a bit earlier this year too. But sheesh, 22degrees in the sound is pretty damn impressive for that part of the coast! Bugger it's put the fish and chips off though.
Just got back from the beach then, howling onshore and cold, but the water felt like bath water, so maybe it's warming up some more. Nice little rip bank too ;-)
Heads up also, 5m white pointer sighted yesterday at OB.
Nah mate, spewing, missed most of that E swell. Orrgh nice you scored though!

southernraw's picture
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southernraw Thursday, 13 Feb 2025 at 3:39pm

btw latest update i just heard on Zelia is that she's packing 350kph winds at the core!!!
Somewhere must be pumping!

Dillosurf's picture
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Dillosurf Thursday, 13 Feb 2025 at 5:13pm

Hope the Ningaloo reef can handle it. That place is absolute magic.

Nick Gee's picture
Nick Gee's picture
Nick Gee Thursday, 13 Feb 2025 at 10:51pm

what sort of water temps up on the North West coast? Like 28 degrees or so?

southernraw's picture
southernraw's picture
southernraw Thursday, 13 Feb 2025 at 11:24pm

This is just anecdotal, but I was seeing stats of 34 degrees C about a month or so ago up through the upper NW @NG.

Craig's picture
Craig's picture
Craig Friday, 14 Feb 2025 at 5:24am

Around 30 with some readings of 32 in and around Port Hedland at the moment..

Lanky Dean's picture
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Lanky Dean Friday, 14 Feb 2025 at 7:35am

That's really hot !

Nick Gee's picture
Nick Gee's picture
Nick Gee Friday, 14 Feb 2025 at 1:39pm

yeah, that’s not good for anything, including a refreshing swim.

Craig's picture
Craig's picture
Craig Friday, 14 Feb 2025 at 5:37am
stunet's picture
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stunet Friday, 14 Feb 2025 at 9:25am

"The JTWC forecast also brings Zelia ashore as a powerful category 5 severe tropical cyclone, with peak wind gusts of around 320 km/h."

https://www.weatherzone.com.au/news/western-australia-bracing-for-category-5-tropical-cyclone/1890366

southernraw's picture
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southernraw Friday, 14 Feb 2025 at 11:02am

Apparently the strongest ever to hit WA.
Reading a few comments from crew in Pt Hedland and they seem determined to ride it out, saying it's just another cyclone. Hope they're right because it looks spooky on the map.

john.callahan's picture
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john.callahan Friday, 14 Feb 2025 at 6:38pm

Those extreme water temperatures off the NW coast feeding Cyclone Zelia - warmer water is like gasoline on a fire for a cyclone system

Craig's picture
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Craig Saturday, 15 Feb 2025 at 7:50am
ruckus's picture
ruckus's picture
ruckus Saturday, 15 Feb 2025 at 2:36pm

Good afternoon senor Craigos, while distressing to see this would have occurred over and over again since the reefs modern inception at the end of the last glacial period – around 11,000 years ago.

For example The Great Barrier Reef is a thin veneer of living coral growing over layers of dead coral - many reefs the dead coral is more than 20 metres thick. Regeneration over regeneration over regeneration - its natures way.

Our observations & experiences are all but a mere spec on the timeline

bbbird's picture
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bbbird Sunday, 16 Feb 2025 at 5:30pm

So life sucks? Geologists paid by mining companies say dig up more dinosaur aged fossil fuels & burn more carbon. Noone wants to cook.

bbbird's picture
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bbbird Sunday, 16 Feb 2025 at 5:46pm

Lesson 6. Sea level has fluctuated as the world’s glaciers grow or recede, and was about 200 feet higher at times when Antarctica was ice-free.

Carbon dioxide levels have risen since the end of the Ice Age, first to a natural level of about 280 p.p.m. just before the start of the Industrial Era, and then to 400 p.p.m. as people burned coal and petroleum in large quantities. Carbon dioxide is currently increasing at a rate of about 2.6 p.p.m. per year. (in 2014)
https://news.climate.columbia.edu/2014/07/11/what-geology-has-to-say-abo...

bbbird's picture
bbbird's picture
bbbird Sunday, 16 Feb 2025 at 6:13pm

What the fossil financied geologists dont tell you is more important
https://www.instagram.com/arctic.basecamp/reel/DFc8rwuNiAu/

reecen's picture
reecen's picture
reecen Monday, 17 Feb 2025 at 6:23pm

Pending world record Cobia caught out of Perth today.
Just shy of 80kg.
Definitely some upsides to this heatwave……

southernraw's picture
southernraw's picture
southernraw Monday, 17 Feb 2025 at 6:48pm

I'll definitely be tuning in to Mark Lecra's fishing report tonight for that one!

Craig's picture
Craig's picture
Craig Friday, 21 Feb 2025 at 10:39am