Welcome La Niña ... again
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
All I see is the Billabong symbol
Sounding a little more positive for Vicco, can't get any worse than the last couple of summers!
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.
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!!
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.
Reef? What’s a reef?
Haven’t seen one of those in a while.
These guys never miss the mark, ha!
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.
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.
I reckon it all depends on who you're cooped up with.
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.
The Betoota Advocate gets straight to the heart of it, Good one Craig that made me smile.
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.
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!
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.
Not ideal!
No Ubers?
Ha ha...keeping my record clean.
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.
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.
yeah, I've been tracking that situation; it's pretty heartbreaking.
Looks like signs of the first cross-equatorial flow this season and vorticity in the SPCZ towards the end of next week.
Yeah there's something brewing.
All this gender specific language is making me feel unsafe.
Hahahaha.... :D
Hi Craig - what impact does La Nina have on the Hawaiian winter?
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,
I've been contemplating a trip to NZ in Feb. Last year looked really good there. East coast and west coast trading great waves.
Yep, not a bad call at all.
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.
That easterly swell tap is primed and ready!
You would have to be thinking flood insurance if you lived on/near Richmond and Clarence rivers.
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.
It's never any good. Probably wouldn't bother trying again if I were you.
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.
Nearbyish. Yep, has been some days down there.
Probably should have stayed an extra day or so though.
Yeah great zone when everything aligns. Have always had great waves and vibes down there, but when a swell is running.
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.
How's all the surrounding bush that was destroyed by the fires. Most of it is bouncing back, but the wildlife...
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.
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.
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.
Wow, what a trip! Got some photos, add them in here if you're keen.. https://www.swellnet.com/forums/wax/490995
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.
Nice, starts with D I'm guessing?
That would be right!
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.
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.
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.
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)
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.
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.
Bit of variation in the models but a couple are suggesting that North Coast system might head out to sea quick, fingers crossed.
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.
"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."
Philippine Dream? Isn't that tucked in nicely and would crank on a NE?
Creek entrances on the Tweed are chocolate brown thanks to 100mm of rainfall in the last 24 hours.
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.
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..
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?
wow, thats insane.
Wettest November since 1900, in NSW.
That's incredible! Def felt like one of the coolest here.
Those soil charts and the Nov stat are really useful. Context is septic system concerns, TMI ha ha.
How are the flood waters and storms offshore..
Yep, fairly solid sediment plume coming out of the Richmond too.
Up here poo...
Saw another interesting stat for Sydney with average sunlight hours for this November being 3hours per day below average.
Very gloomy weather for November and the rain just keeps coming. And that is before any tropical lows or cyclones have kicked in.
@Belly might be time for another trench…
Interesting.
Where might I find such statistics Distracted?
On any BOM weather station page go to "Recent months" under the station details. Then click November 21 under "Other times and other places" and see the column Sun and the mean at the bottom.. http://www.bom.gov.au/climate/dwo/202111/html/IDCJDW2125.202111.shtml
Sydney comes in at 4.9, when the average here is 7.7 http://www.bom.gov.au/climate/averages/tables/cw_066037.shtml
Thanks mate.
Ha ha thanks Distracted. We know. Only 14 months in to our septic rural journey, both my partner and I have rural roots.
Guess we're hoping for a dry run and it comes good but we've received advice it won't! Our issue is secondary location, on a couple of acres and once outside of the immediate house yard the paddock is quite heavily forested. Don't want to say goodbye to too many trees. Then there's the cost.
Clay soils and wet weather aren’t good for septics on small lots and an extra trench isn’t always feasible which makes it tricky… and potentially expensive.
Similar to Craig’s link above there is also an evapotranspiration column for some of the weather stations which will relate to septic performance. If there is more rain than evapotranspiration then the soils will start to saturate and then there is the additional load from the system itself…. Fingers crossed the sun comes out!
http://www.bom.gov.au/watl/eto/
Cheers for the extra information distracted!
Nice Distracted, never knew!
Might be less sunlight but it hasn't stopped the weeds.
been spending hrs on the brush cutter and barely making a dent in it.
The joint is so green and alive it looks like Sumatra. Lay down and the plants will grow straight through you!
Check the ground cover it the second photo. It’s like a green version of the Martian slime which coated the Earth in in War of the worlds. Feels a treat to walk over in bare feet.
same here re the weeds FR, and the vibrant greenness Blowin. So far, these La Nina rains havent missed me this time around. Stoked. Been great steady rain, and intense bursts in between, so nothing damaging. And had plenty of 'waterfall nights' - where the tanks are overflowing onto a rocky outcrop/creek bed set-up I installed, just outside my bedroom window. Sounds great
lush times, but much to do to keep it all in check
I don't know if it's a thing but does La Nina = LAGO's for the east coast?
Makes sense with all the arvo storm action. Something I've noticed of lately. Not complaining.
Yep it's definitely more likely with all this troughy weather and moisture as it's preventing the land from heating up which gets that sea breeze cycle kicking. Add in the warmer water from the lack of upwelling and it's a win win.
Latest SST anomaly update, La Niña is looking robust. Lots of warm water surrounding Australia now.
Also the East Australian Current is flowing nicely..