ENSO Wrap-Up: Tropical Pacific neutral; chance of La Niña increases
Issued on Wednesday 26 May 2010 | Product Code IDCKGEWWOO
Climate indicators across the equatorial Pacific are currently neutral. Equatorial Pacific Ocean temperatures, trade winds, the Southern Oscillation Index and cloudiness over the Pacific are all at levels considered typical of neutral conditions (i.e. neither El Niño nor La Niña).
Historically, about 35~40% of El Niño events are followed by a La Niña within the same year. Currently, a large volume of cooler than normal water is present below the surface of the equatorial Pacific Ocean, which indicates that further cooling of the surface of the tropical Pacific is likely.
International climate models predict continued cooling of the Pacific Ocean sea surface, with the majority of models surveyed by the Bureau predicting that this cooling will be sufficient to see the development of La Niña conditions later in the year. No climate models suggest a return to El Niño conditions. It should be noted that correctly predicting transitional periods of the El Niño Southern Oscillation is more difficult than predicting the continuation or decline of El Niño or La Niña events.
I always thought we wanted to see el nino conditions on the East Coast to increase the strength and frequency of North Easterlies through summer? Always felt a bit guilty as it generally means drought and bushfires to the rest of the population, but I was dealing with it.....
^ yeah, se ya later seabreezes,
but i prefer the cyclones, east coast lows and general strong SE winds.
so always look forward to la nina events.
Since it's been pissing down for the last 2 yrs, how are we not in a La Nina, and if not, does that mean it's all bogus anyway ?
Now, I have not followed this thing terribly closely, but on the few occasions I have taken notice of what the predictions were, they have been wrong.
That said, I'd love some more big southerlies thanks, but only after a cracking season of north wind !!!
PS I'm in considerable pain today after training a bit for my Maui trip, in case anyone is feeling unsympathetic and wants to bag me out for my trouble !!
May be good for Queenslanders but for NSW it means more wet summers with the usual doldrums. As Ken says, its was a wet and ordinary summer this year. There were decent seabreezes up till Christmas Eve but after that, bugger all until sometime in March.
yes, its been crap here also through that same period. this year up hear we barely got a SE wind to speak of. meant 2-3 months of poor winds not getting over 20 knots much. up here we don't see seabreezes much over 22 knots. but most SE winds are 20-30 knots.
the period we are all talking about was not la nina, it was el neno or neutral as shown by the graph
the last month has seen wind down south though.
the sst map below indicates higher temps in the areas that have bee ngetting the wind.
so la nina will see higher temps further up the east coast if it comes off an more chance of lows forming and driving in the wind.
anyone want to buy a 4.7m sail. ![]()
^ i don't know what it means for the south coast during la nina. last la nina we had the WA crew had an ordinary season though from what was posted on seabreeze.
how has the last 2 months been for you?
this is what it means for south australia
Sea surface temperatures in the Pacific Ocean can affect rainfall right across Australia, but their most direct link is to rainfall in the eastern half of Australia.
The El Ni?o - Southern Oscillation (ENSO) is a major influence on Australia's climate, though its effect is less marked over much of South Australia than for areas further east.
ENSO is the oscillation between El Ni?o and La Ni?a conditions, interspersed with neutral periods.
These events are triggered by variations in sea surface temperature in the central and eastern tropical Pacific Ocean.
and the link -http://www.climatekelpie.com.au/understand-climate/weather-and-climate-drivers/south-australia
plus this
www.bom.gov.au/lam/climate/levelthree/ausclim/ausclimsa.htm
last 2 months not memorable,typically autumnish,the odd windy day.
our wind at the moment is from cold fronts-sthwestlys and high pressure systems creating northerlywinds--if the centre of the highs sit around central aus we usually have good northerlys--if they sit lower we dont.
rule of thumb here is in winter,if we have good weather,sunny skies,you have crapp conditions in qld,ie--plenty of wind.--and vice versa
^ i might need to go back to the drawing board then.
typically up here a high means no wind also. only along the edge where it pushes against a low do we get any wind.
i was working on the theory that the higher sea surface temp anomilies would intensify low pressure systems meaning more chance of wind and stronger cold fronts with more thunderstorms associated.
then after the front passes you get colder sea surface temps from upwelling.
maybe that only happens in the tropics.
but none of this is related to la nina, i kinda posted 2 threads in one.
and the third thread is that i'm reading some stuff that the fishing should be better after the bad weather has passed because of upwelling which is indicated by cooler sst's.
The big thing here is that looking at factors like ENSO, and sea surfaces temps etc, is to try and predict weather at a "complicated" level, much like a car at rest. It's a complicated mechanism.
However, weather is not complicated, it is "complex", like a car in motion, where the parts of that complicated mechanism starts interacting with each other and the surrounding environment.
Weather is also an emergent system, meaning, that even though it is governed by a consistent set of rules, there are so many rules interacting with each other, that you have to run the system to see what will actually happen rather than be able to predict what will happen.
Smarter people than me have defined about 3 days as the limit before predictive models start disintegrate in the exponential explosion of permutations and combinations.
Put more simple it's like trying to shoot charlies when playing pool. Looks simple, no-one has ever done it.
what about down south?
so i did some more research and it appears that it's the opposite to what i was thinking. around south OZ positive SSTA's indicate lighter winds and negative SSTA's indicate stronger winds. that's the opposite to what we get up here.http://www.bom.gov.au/events/9icshmo/manuscripts/PM_B6_Watterson.pdf
the main controlling factor for weather around south australia is the SAM. positive sam usually accompanies positive SSTA's in the mid latitudes.
for good frontal systems to the south a negative SAM is better. that includes new zealand also.
the SAM controls the position of the frontal line in the mid latitudes. positive sees the frontals roll through in the southern ocean with highs over South australa/victoria and negative sees them roll through higher up over south australia victoria with highs over the southern ocean.
www.niwa.co.nz/news-and-publications/publications/all/wa/14-2/sam
so to see what the weather is most likely to produce look to the SAM charts. i think this is mainly a winter setup also?
www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/aao/aao_index.html
victoria weather. www.climatekelpie.com.au/understand-climate/weather-and-climate-drivers/victoria
sand point and a negative sam would be good most likely.
And I thought it was just about those red and green arrows.
I think I may be a bit simple because the most I can understand is if the arrows show red then it definitely isn't any good and if the arrows show green then it probably isn't any good
^ that works too. ![]()
i like to see ahead further than 1 week so trying to understand the bigger picture helps.
last time i used my 4.7m sail was during a la nina season and with another one possibly on the way the 4.7 will get use again. i've even bought gear based on long range forecasts in the past. i was going to buy a sup but if the la nina holds true i won't bother.
who knows what's going to happen in the end.
there should be lots of wind around vic around the 18th and from july to march in SEQ should be fantastic but of course it may not.
Do you record what days you sailed and what it was like to compare forecast with actual ?
Or do you just sort of remember each time and draw a general conclusion.
Would it help if everybody recorded where they sailed and what board / sail size they used ?
Is that too anal, or giving away too many secrets, or just a waste of time ?
I've always noticed that if it is a wet autumn, then it tends to be a mild winter, implying fewer strong south westerly winds
Last year as an example.
Does that gel with things ?
Cold water surface temperatures, especially during summer, will possibly increase the number and intensity of NE seabreezes.
A seabreeze, I believe, is supposedly caused by the temperature differential between the temperature of the land and the temperature of the sea.
As the land temperature increases during the day, the heated air above it rises and is replaced by the cooler air over the adjacent sea. The greater the temperature difference between the land and the sea, the stronger the breeze.
Sydney, over the last 20 years, has experienced warmer sea temperatures, as well as warmer over night land temperatures (Heat Island effect). Since the land temperature starts the day higher than it did previously, less air will rise than if the temperature were lower. Add to that a warmer sea temperature and we get an overall reduced temperature differential between the land and the sea, and therefore, reduced sea breezes.
And the biggest SE winds come when there is a low up north and a high down south just touching at the edges. THe area at that conjunction really gets windy !!
We used to get that in Bundaberg a bit, and it produced a lot of wind.
One year, I sailed small gear every day for over 3 weeks.
Maybe that year or the next I used a 4.0 over 20 times in a late summer/autumn period.
the last 2 burrum events we have missed out on cyclones by 2-4 weeks or there abouts. both were la nina and el nino years so it will happen in time.
the big difference was that this year the SE winds didn't kick back in after the cyclone passed where as the previous year they did. whether that is directly related to enso i'm not sure.
with the green island week, it is a guess but if we do get a la nina this winter i would think the chances of good winds are a lot higher. maybe ![]()
these are all of the computer models that are collated to figure out enso trends. becasue they are forecasting the eastern side a drop on the graph is reflected by an increase over here.
link iri.columbia.edu/our-expertise/climate/enso/
Just before that cyclone event, someone on here posted that a cyclone is often followed by a windless period. I recall thinking they had been right.
A big clonic stirs up a lot of cool water sometimes, if it sits in one place.
I remember a whopper out near Fiji that just sat there and died in a puddle of coolwater of it's own making.
I would also take cyclones out of the usual modelling, because they say more about specific conditions conducive to low formation than they do about highs.
Conditions vary a lot over a relaively short distance too. When I was in Bundaberg, I asked the locals what sorts of northerly season they ahd, and they said it was pretty ordinary. That contrasts pretty strongly with the great season we had a few hundred km away.