Welcome La Niña ... again

Craig Brokensha picture
Craig Brokensha (Craig)
Swellnet Analysis

It’s not news to Swellnet readers, but La Niña has been officially called by the Australian Bureau of Meteorology for the coming summer. It's the return event we’ve been talking about since early autumn.

Following any first year La Niña, statistically the odds of a second La Niña - called a 'double-dip' La Niña - sit at 50%, and earlier this year the Pacific Ocean showed signs that a back to back event was likely. The chances of a trifecta are remote. The last time that happened was in the years 1973/74/75. 

As the rain comes down across the eastern seaboard, anyone who’s travelled inland over the past month would have noticed how lush the landscape is. These inland falls have been associated with the negative Indian Ocean Dipole (IOD) through winter and spring. The IOD is a signal similar to El Niño/La Niña though in the Indian Ocean where warm water piles up towards the east, under Indonesia and north-west of Australia.

The increased sea surface temperatures provide mositure to the atmosphere which is then drawn down, south-east across the country.

Negative IOD events generally coincide with La Niña, so as we transition from spring to summer, Australia will fall under the influence of the Pacific Ocean rather than the Indian Ocean.

A classic La Niña signal has set up in the Pacific Ocean

The mechanics behind El Niño/La Niña events are the easterly trade winds across the equatorial Pacific Ocean. If these winds become stronger than normal during winter and spring, they upwell cool water in the eastern Pacific while warmer water piles up to the west, around northern Australia.

This is known as La Niña while the counter to this El Niño, where the trades weaken and even reverse to the west which sees warm water piling up to the east, with cooler water around northern Australia. Neutral years fall between these two scenarios. In our last article I mentioned the possiblity that this season's La Niña will have a Modoki twist, but this looks less likely with the cold water anomalies now being strongest further east.

With warmer water surrounding Australia under the current La Niña scenario, we're seeing more convection and instability, resulting in increased rainfall across the north of the country. Also, the corresponding lower pressure is pushing the sub-tropical high pressure belt further south than normal, opening up the East Coast to easterly trade-winds and a stream of moist, onshore air.

Besides the wetter weather it means more swell for the East Coast and with generally favourable winds owing to troughy, unstable weather.

There’s also an increased risk of Tropical Cyclones (TC) owing to the warmer water which they feed off. Last month, the Bureau of Meteorology released their Tropical Cyclone outlook for the coming season and the Eastern Region - which extends from the Queensland coast to roughly New Caledonia - is forecast to see four TCs with a 59% chance of more, while further east towards Fiji - a region that can still generate swell for SE QLD and N NSW - six are forecast.

For the north-western and western regions there are five and seven cyclones forecast respectively with a 61-62% chance of more forming.

Keeping in mind that cyclones aren’t always the best swell producers due to their small, focussed nature. Regardless, the persistent easterly trade-wind setup should provide plenty of surf out of the east for the coming summer and early autumn on the East Coast.

Thursday, November 26th, surrounded by moisture

The downside of the sub-tropical ridge drifting further south is that it generates a blocking pattern across the southern states resulting in smaller swells out of the south and winds out of the east. One positive this year compared to last is that winds look to be more favourable due to instability inland, providing a few more options on the beaches.

For Western Australia, a large blocking pattern to the south-west looks to also keep a lid on any incoming swell activity while coastal troughs bring hotter, offshore winds.

We’ll provide a more detailed seasonal outlook for the summer ahead once the next update from the seasonal forecast models comes through.

The Bureau of Meteorology have created this great clip explaining the IOD and La Niña.

Comments

Nick Bone's picture
Nick Bone's picture
Nick Bone Friday, 26 Nov 2021 at 9:01am

All I see is the Billabong symbol

geek's picture
geek's picture
geek Friday, 26 Nov 2021 at 9:34am

Sounding a little more positive for Vicco, can't get any worse than the last couple of summers!

Blowin's picture
Blowin's picture
Blowin Friday, 26 Nov 2021 at 9:53am

This rain is a blessing and I’m a massive fan of La Niña. Having said that, there’s no escaping the fact that the East coast is a dreary place to be at this time of year if you’re a fan of good waves. After an excellent run through autumn and winter I was starting to think that the whole “Least Coast” concept might be a bit overblown. Don’t think I’ve seen a decent wave in a few weeks.

Looks like I picked the wrong time to give up surfing in Indonesia.

Good article Craig. Thanks.

joesydney's picture
joesydney's picture
joesydney Friday, 26 Nov 2021 at 10:15am

Depends where you surf - offshore and south swells where I surf are a shitfight. Crowded and generally closing out.
Last night I surfed by myself in the rain and a bit of lightening and it was a little junky and rippy which made it hard work but that keeps people away and I picked off some fun waves.
I say bring it on!!

MrBungle's picture
MrBungle's picture
MrBungle Friday, 26 Nov 2021 at 11:00am

Some of the more fun reefs around my area light up with a 7-10 second E to NE wind swell under 2 meters, you just need to be on the pulse when the tide/winds line up. Summer can be great if you keep an eye out, you just can't rely on a nice groomed swell and offshore winds every week like you can Autumn through Winter. I find that Autumn is usually the sweet spot for variety on the South Coast of NSW though.

Blowin's picture
Blowin's picture
Blowin Friday, 26 Nov 2021 at 11:23am

Reef? What’s a reef?

Haven’t seen one of those in a while.

Craig's picture
Craig's picture
Craig Friday, 26 Nov 2021 at 9:57am

These guys never miss the mark, ha!

thermalben's picture
thermalben's picture
thermalben Friday, 26 Nov 2021 at 11:17am

Shithouse time for vanlyfers. All fun and games when it's dry, but the back of a Hiace is a terrible place to be cooped up in during these extended wet spells.

ryder's picture
ryder's picture
ryder Friday, 26 Nov 2021 at 2:02pm

Fuck 'em Ben!
Hopefully a terribly wet summer stuck in a musky tin hovel will ware them down, to the point they stay away from warmer sub-tropical parts of Australia next winter.

tango's picture
tango's picture
tango Monday, 29 Nov 2021 at 9:42am

I reckon it all depends on who you're cooped up with.

Standingleft's picture
Standingleft's picture
Standingleft Friday, 26 Nov 2021 at 10:01am

Thanks for your in depth analysis and that BOM vid is comprehensive.
Geek, I think Craig has tried to put a positive spin on it for us Viccos but the fact is the highs are in a more southerly position and while I'm happy for our east coast brothers & sisters and I think I'll take the flooding rains over droughts but it's a poor outlook for the Surfcoast.

Ash's picture
Ash's picture
Ash Friday, 26 Nov 2021 at 10:11am

The Betoota Advocate gets straight to the heart of it, Good one Craig that made me smile.

Blowin's picture
Blowin's picture
Blowin Friday, 26 Nov 2021 at 10:12am

Pissing down right now….it’s glorious!

I remember in the shitful bushfire year of 2019 we had something like 250mm of rain for the whole year. It was my first time in decades doing a ( nearly) complete 12 months on the Least Coast and I thought that was normal!

Places around here just had 200 odd mills in the last few days alone with more falling and this isn’t even considered a hectic rain around here apparently. It’s truly a thing of beauty.

2019 was fucked up. It was like the dryness of the land tied in with a drought of spiritual nourishment. Worst year of my life easily.

Craig's picture
Craig's picture
Craig Friday, 26 Nov 2021 at 10:18am

Yeah we had a Swellnet catchup the last three days around Ballina. The atmosphere was saturated and the misty, moody vibes fully set in. Saw the sun for about an hour Tuesday.

The flight home seeing the storms setup across the MNC and pushing off Sydney was great as well!

stunet's picture
stunet's picture
stunet Friday, 26 Nov 2021 at 11:50am

Wasn't so fun when one of those Sydney storms took out the signals on the Illawarra Line leaving me stranded on a train platform with a thousand frustrated punters all itching to get home.

Craig's picture
Craig's picture
Craig Friday, 26 Nov 2021 at 11:53am

Not ideal!

freeride76's picture
freeride76's picture
freeride76 Friday, 26 Nov 2021 at 12:02pm

No Ubers?

stunet's picture
stunet's picture
stunet Friday, 26 Nov 2021 at 12:06pm

Ha ha...keeping my record clean.

freeride76's picture
freeride76's picture
freeride76 Friday, 26 Nov 2021 at 11:26am

Seems like this Nina has been front loaded with massive moisture infeeds from the Arafura Sea into the interior troughs.
Could get interesting if we start getting big moisture infeeds from the Pacific as well.

Lots of river basins already flooding/saturated, but mostly west of the Divide.

lomah's picture
lomah's picture
lomah Friday, 26 Nov 2021 at 11:38am

feel for the crew west of the great divide they were looking down the barrel of a once in a generation crop. combo of incredible yields and sky high grain prices. here's hoping they manage to get a crop off - even if quality and $ down due to degradation as a result of moisture. small silver lining - sub soil moisture profiles should hold them in good stead for awhile following this summer.

freeride76's picture
freeride76's picture
freeride76 Friday, 26 Nov 2021 at 11:52am

yeah, I've been tracking that situation; it's pretty heartbreaking.

freeride76's picture
freeride76's picture
freeride76 Friday, 26 Nov 2021 at 12:24pm

Looks like signs of the first cross-equatorial flow this season and vorticity in the SPCZ towards the end of next week.

Craig's picture
Craig's picture
Craig Friday, 26 Nov 2021 at 12:34pm

Yeah there's something brewing.

Michael Adam's picture
Michael Adam's picture
Michael Adam Friday, 26 Nov 2021 at 1:08pm

All this gender specific language is making me feel unsafe.

muffsic's picture
muffsic's picture
muffsic Friday, 26 Nov 2021 at 3:00pm

Hi Craig - what impact does La Nina have on the Hawaiian winter?

Craig's picture
Craig's picture
Craig Friday, 26 Nov 2021 at 3:07pm

Typically with La Niña's the storm track in the North Pacific is positioned further north, away from Hawaii, then dips down into North America.

El Niño's see the storm track positioned more southward towards Hawaii, hence bringing a larger, more active season.

As always you can still get a good season with La Niña's but I'd expect it to be a slightly below average one. Those warm water anomalies east of Japan will help feed any storms spawning from the west though,

spinafex's picture
spinafex's picture
spinafex Friday, 26 Nov 2021 at 3:16pm

I've been contemplating a trip to NZ in Feb. Last year looked really good there. East coast and west coast trading great waves.

Craig's picture
Craig's picture
Craig Friday, 26 Nov 2021 at 3:17pm

Yep, not a bad call at all.

Nardi's picture
Nardi's picture
Nardi Saturday, 27 Nov 2021 at 6:13pm

Not to give up all my secrets, but planes (I’m sure most crew know this anyway) land nose into the breeze. Hence pick port/starboard window seat for optimal coastal views according to breeze on the day(coming in to Sydney). Grew up in the Royal National park and love banking over that coast for a landing into a nor Easter in summer. Holding pattern takes you right over the north end of my favourite beachy too.

Matilda0213's picture
Matilda0213's picture
Matilda0213 Sunday, 28 Nov 2021 at 7:04am

That easterly swell tap is primed and ready!

No mal half a quiver's picture
No mal half a quiver's picture
No mal half a quiver Sunday, 28 Nov 2021 at 8:16am

You would have to be thinking flood insurance if you lived on/near Richmond and Clarence rivers.

memlasurf's picture
memlasurf's picture
memlasurf Sunday, 28 Nov 2021 at 9:56pm

Just got back from a deep and cold soaking on the far south coast. And people whinge about Melbourne’s weather this was way worse. We get swell and sunny weather, down there it seems it needs to be totally miserable to get waves or maybe just a bad week. Was wet but.

mcbain's picture
mcbain's picture
mcbain Monday, 29 Nov 2021 at 10:23am

It's never any good. Probably wouldn't bother trying again if I were you.

memlasurf's picture
memlasurf's picture
memlasurf Monday, 29 Nov 2021 at 12:19pm

Ha yeah and you live probably in Merimbula. Have had so many hit and miss efforts since 1977 so have had it really good, usually when the weather is rubbish and had it flat as a tack when the sun is out. Beautiful part of OZ just fluky for surf although the locals say they have had a good run of late.

mcbain's picture
mcbain's picture
mcbain Monday, 29 Nov 2021 at 12:23pm

Nearbyish. Yep, has been some days down there.
Probably should have stayed an extra day or so though.

Craig's picture
Craig's picture
Craig Monday, 29 Nov 2021 at 12:27pm

Yeah great zone when everything aligns. Have always had great waves and vibes down there, but when a swell is running.

memlasurf's picture
memlasurf's picture
memlasurf Monday, 29 Nov 2021 at 12:30pm

I know had to leave at the crack of dawn Sunday and it finally went offshore and was looking the goods. Still was a nice break and good to go somewhere else.

Craig's picture
Craig's picture
Craig Monday, 29 Nov 2021 at 12:33pm

How's all the surrounding bush that was destroyed by the fires. Most of it is bouncing back, but the wildlife...

memlasurf's picture
memlasurf's picture
memlasurf Monday, 29 Nov 2021 at 1:58pm

Craig, rode the bikes up through Walhalla to Mansfield, Omeo, Jindabyne, then Merimbula mostly through gravel roads and bushland. Yeah some areas particularly north and east of Omeo and around the NSW sky fields was really bad but all with epicormic shoots on the gums (except of course the Mountain and Alpine Ash) and lots of new growth at ground level. Going to be really slow as there is so much brilliant bush in this corner of OZ. For mine it is my favourite part of our continent. Was weird as due to the lack of veg' you could see for miles and see the extent of the fires which was massive. Wildlife was OK from what I experienced, often up close missing multiple Magpies, Wallabies, Kanga's and Echinda's. Lots of dead Wombats on the asphalt roads which is upsetting but they do seem plentiful. On a slow mend.

Craig's picture
Craig's picture
Craig Monday, 29 Nov 2021 at 2:04pm

That's good to hear and I agree, so unique and wild out there! What sort of bikes were you on? MTB on stop overs with the car? Yeah wombats are everywhere but it's good to hear about the other fauna.

memlasurf's picture
memlasurf's picture
memlasurf Monday, 29 Nov 2021 at 2:17pm

No we have ADV bikes, a God Sillier (GS) bimmer and a Ducati Desert Sled, I'm a rev head which is very contradictory, but... A mate drove up who is not into bikes and met us at Merimbula with the boards and wetties. First half holiday with the combustion engine brigade; second half with the boards. Lot of fun and adventure was had by all.

Craig's picture
Craig's picture
Craig Monday, 29 Nov 2021 at 2:20pm

Wow, what a trip! Got some photos, add them in here if you're keen.. https://www.swellnet.com/forums/wax/490995

mcbain's picture
mcbain's picture
mcbain Monday, 29 Nov 2021 at 2:14pm

My brother did a spotlight session the other night in a patch adjacent to a coastal burnt area a bit further up the coast. 8 greater gliders in a couple of hours and a bunch of other stuff - not that that is necessarily indicative of overall fauna impacts. You'd know him Craig - mainly from the snow.

Craig's picture
Craig's picture
Craig Tuesday, 30 Nov 2021 at 6:45am

Nice, starts with D I'm guessing?

mcbain's picture
mcbain's picture
mcbain Tuesday, 30 Nov 2021 at 9:57am

That would be right!

Craig's picture
Craig's picture
Craig Monday, 29 Nov 2021 at 10:53am

The Madden Julian Oscillation is set to strength a little in the Western Pacific over the coming fortnight, should bring a bit more instability and the formation of a tropical low or two.

The poo man's picture
The poo man's picture
The poo man Monday, 29 Nov 2021 at 2:04pm

What I read in this article: correct
Correct
Correct
Correct .
And did no mention the word global warming.
It's not often you hear anyone talking about climate events like la nina elnino without spinning this man made global warming bs. So who cares about la nina when the waves are good and the dams a full.

Craig's picture
Craig's picture
Craig Monday, 29 Nov 2021 at 2:11pm

Ha, well sorry to burst your bubble TPM.

La Niña years are generally cooler globally compared to the long term average, but even with the current back to back Niña's, we're still seeing the global temperature for 2021 sitting above the long-term average and being 7th warmest on record (black line).

Not a good trend with the 'cooler' years being still warmer than what we've seen before.

Craig's picture
Craig's picture
Craig Monday, 29 Nov 2021 at 2:17pm

You can also see previous La Niña years here (dips under the black trend line) since the 1970's and they're now trending above the average temperature.

Since about the 2,000's the La Niña years, while being cooler globally have been warmer than the climate average from (1981-2010)

memlasurf's picture
memlasurf's picture
memlasurf Wednesday, 1 Dec 2021 at 11:41am

Even Stevens Craig or maybe a bit more Nina than Nino? Average really isn't as such looks like a transition from one to the other on this graph with the whole lot going up. Interestingly, summer of 1980-81 were cooker's down here and started in November and went right the way through to March which corresponds with upswing at that point.

freeride76's picture
freeride76's picture
freeride76 Tuesday, 30 Nov 2021 at 2:50pm

Flood Watch current for Wilsons and Richmond River.

Really coming down in buckets now.

I think November rainfall records might be set in some areas/catchments.

Distracted's picture
Distracted's picture
Distracted Tuesday, 30 Nov 2021 at 9:55pm

Bit of variation in the models but a couple are suggesting that North Coast system might head out to sea quick, fingers crossed.

freeride76's picture
freeride76's picture
freeride76 Wednesday, 1 Dec 2021 at 10:02am

Crazy strong Amihan (NE monsoon) pattern through the Western Central/North Pacific right now.

Be some insane surf at spots that fire on that pattern.

Craig's picture
Craig's picture
Craig Wednesday, 1 Dec 2021 at 11:05am

"In the Philippines, Amihan refers to the season dominated by the trade winds, which are experienced in the Philippines as a cool northeast wind. It is characterized by moderate temperatures, little or no rainfall in the central and western part of Luzon and Visayas, and a prevailing wind from the east. On the east coast of Luzon it brings drizzling rainfall and squalls. The effect on Mindanao relatively less than in the northern part of the country."

Nice Steve!

And..

"Amihan (mythology) is a bird in the Philippine mythology. According to the Tagalog folklore, Amihan is the first creature to inhabit the universe, along with the gods called Bathala and Aman Sinaya. In the legend Amihan is described as a bird that saves the first human beings, Malakas and Maganda, from a bamboo plant."

Island Bay's picture
Island Bay's picture
Island Bay Wednesday, 1 Dec 2021 at 12:07pm

Philippine Dream? Isn't that tucked in nicely and would crank on a NE?

thermalben's picture
thermalben's picture
thermalben Wednesday, 1 Dec 2021 at 11:31am

Creek entrances on the Tweed are chocolate brown thanks to 100mm of rainfall in the last 24 hours.

freeride76's picture
freeride76's picture
freeride76 Wednesday, 1 Dec 2021 at 11:36am

Soil moisture profiles are now completely saturated in catchments for Wilsons/Richmond.

Very high risk for flooding if we get another event in the next month.

Craig's picture
Craig's picture
Craig Wednesday, 1 Dec 2021 at 11:46am

Yeah check the relative soil moisture charts (to long term average) for now compared to the lead up to the horrific 2019/20 fire season..

Now..

30th Nov 2019..

And the current actual soil moisture levels..

Craig's picture
Craig's picture
Craig Wednesday, 1 Dec 2021 at 11:49am

Interesting to see the West Coast of Tasmania is apparently near 100% root zone soil moisture, but on the relative chart below average. An error?

freeride76's picture
freeride76's picture
freeride76 Wednesday, 1 Dec 2021 at 11:50am

wow, thats insane.

freeride76's picture
freeride76's picture
freeride76 Thursday, 2 Dec 2021 at 6:00am

Wettest November since 1900, in NSW.

Craig's picture
Craig's picture
Craig Thursday, 2 Dec 2021 at 6:06am

That's incredible! Def felt like one of the coolest here.

belly's picture
belly's picture
belly Thursday, 2 Dec 2021 at 6:51am

Those soil charts and the Nov stat are really useful. Context is septic system concerns, TMI ha ha.

Craig's picture
Craig's picture
Craig Thursday, 2 Dec 2021 at 1:42pm

How are the flood waters and storms offshore..

freeride76's picture
freeride76's picture
freeride76 Thursday, 2 Dec 2021 at 2:27pm

Yep, fairly solid sediment plume coming out of the Richmond too.

Sprout's picture
Sprout's picture
Sprout Thursday, 2 Dec 2021 at 2:53pm

Up here poo...