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#1422812 - 05/05/2017 16:36 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: Multiversity]
snowbooby Offline
Cloud Gazer

Registered: 11/05/2016
Posts: 30
Originally Posted By: Multiversity
However recently there hasn't been the anticipated reversal which sparks the question, why?

If you look in the thread titled Qbo in this section you'll see an abstract which speculates it was connected to off-equator wave driving

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#1422814 - 05/05/2017 17:20 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: Mike Hauber]
Mega Offline
Meteorological Motor Mouth

Registered: 03/02/2003
Posts: 6235
Loc: Maryborough, Wide Bay, QLD
Originally Posted By: Mike Hauber

The normal pattern for el nino development is strong westerly winds to the west of the dateline, and alternating periods of westerly activity with return to normal trade winds. That is why they are called westerly wind bursts


I understand this. However surely you wouldn't expect to see trade winds return so strong immediately after a WWB if the Pacific was ready to transition into an El-Nino? Also, how many WWB's have we had already? I ask this because: "On average, three of these events take place each year, but are significantly more common during El Niño years."


Originally Posted By: Mike Hauber
I said current conditions are full steam towards el nino. What may or may not happen in two weeks is not current conditions. CFS forecast for a return to normal conditions is quite consistent with what has happened in past developing el ninos. EC is a strong enough trade wind surge I'd expect it to put a significant slow down on development, but I note it looks similar strength to what happened in March, which had minimal impact on the recent warming trend.


What is 'normal' though? Because while average trades may be considered normal, above average trade winds are not. Also, you say the last burst of trade winds had minimal affect on the warming trend, I'm not so sure about that. If those trade winds were below average then the warming would have been quicker like some of the models originally suggested it would be.

Originally Posted By: Mike Hauber
CFS and POAMA have backed off considerably. But JMA has gone the other way and after a long period of being the one model forecasting cooler conditions it has joined many other models with a weak el nino forecast. NASA has gone from strong to moderate el nino. EC is holding steady, and has to me been the pick of the models for the last year, pretty much nailing last summer as being neutral when every other man and his dog were banging on about a la nina.


Add UKMET to the list of models that backed off considerably. I'm aware JMA and EC have stayed consistently warm though, yes, however don't forget that EC was one of the models in 2014 that was consistently calling for a Super Nino that never happened ( link ) , so I wouldn't be surprised if there was some warming bias there. But again we'll just have to wait & see.

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#1422821 - 05/05/2017 21:02 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mega Offline
Meteorological Motor Mouth

Registered: 03/02/2003
Posts: 6235
Loc: Maryborough, Wide Bay, QLD
Just realised the link in my previous post was to EC's forecast of Nino 3, not 3.4, in April 2014. Here is the 3.4 plume for April 2014...and the subsurface looked much more primed for El-Nino during that year than it does now (Link)

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#1422912 - 08/05/2017 05:19 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: Mega]
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 2488
Loc: Buderim
Originally Posted By: Mega
Originally Posted By: Mike Hauber

The normal pattern for el nino development is strong westerly winds to the west of the dateline, and alternating periods of westerly activity with return to normal trade winds. That is why they are called westerly wind bursts


I understand this. However surely you wouldn't expect to see trade winds return so strong immediately after a WWB if the Pacific was ready to transition into an El-Nino? Also, how many WWB's have we had already? I ask this because: "On average, three of these events take place each year, but are significantly more common during El Niño years."


Originally Posted By: Mike Hauber
I said current conditions are full steam towards el nino. What may or may not happen in two weeks is not current conditions. CFS forecast for a return to normal conditions is quite consistent with what has happened in past developing el ninos. EC is a strong enough trade wind surge I'd expect it to put a significant slow down on development, but I note it looks similar strength to what happened in March, which had minimal impact on the recent warming trend.


What is 'normal' though? Because while average trades may be considered normal, above average trade winds are not. Also, you say the last burst of trade winds had minimal affect on the warming trend, I'm not so sure about that. If those trade winds were below average then the warming would have been quicker like some of the models originally suggested it would be.

Originally Posted By: Mike Hauber
CFS and POAMA have backed off considerably. But JMA has gone the other way and after a long period of being the one model forecasting cooler conditions it has joined many other models with a weak el nino forecast. NASA has gone from strong to moderate el nino. EC is holding steady, and has to me been the pick of the models for the last year, pretty much nailing last summer as being neutral when every other man and his dog were banging on about a la nina.


Add UKMET to the list of models that backed off considerably. I'm aware JMA and EC have stayed consistently warm though, yes, however don't forget that EC was one of the models in 2014 that was consistently calling for a Super Nino that never happened ( link ) , so I wouldn't be surprised if there was some warming bias there. But again we'll just have to wait & see.


That was the strongest forecast from early 2014, and its probably only the March to May forecasts that looked like a super el nino to me. Not sure that I would call that conistently calling for a super el nino. The period that EC was forecasting more of the spread above what happened than below went for longer.

The forecast from January 2015 somewhat underestimated the 2015 el nino, with lesser underestimation a a couple more months other side. Is this what you would term consistently underestimating the 2015 event and evidence for a cold bias?

In both cases the actual result was within the range forecast by EC, which is what is expected in weather modelling. Currently that means anything from barely warm neutral to very strong el nino.

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#1422990 - 09/05/2017 08:09 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mega Offline
Meteorological Motor Mouth

Registered: 03/02/2003
Posts: 6235
Loc: Maryborough, Wide Bay, QLD
POAMA has gone even more neutral:



ENSO wrap-up due out today.

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#1422992 - 09/05/2017 08:42 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
pete28 Offline
Weatherzone Addict

Registered: 08/01/2007
Posts: 1069
Loc: Christchurch, New Zealand
Good news if you like sea level snow events here in Canterbury, low level snow events tend to happen more in neutral years down in this part of the world...

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#1423042 - 10/05/2017 10:08 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: Mike Hauber]
ColdFront Offline
Meteorological Motor Mouth

Registered: 29/06/2008
Posts: 17198
Loc: Wide Bay..Near the beach
Originally Posted By: Mike Hauber

In both cases the actual result was within the range forecast by EC, which is what is expected in weather modelling. Currently that means anything from barely warm neutral to very strong el nino.


That's quite a hedge at 50%. Toss a coin?
_________________________
“ Trump thinks an impeachment involves fruit

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#1423102 - 11/05/2017 09:07 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
RC Offline
Weatherzone Addict

Registered: 29/09/2007
Posts: 1914
Loc: near Rockhampton, Qld
Certainly some models are backing off a bit now the unpredictability barrier is done.

Still get warm though, maybe slight El Nino.

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#1423108 - 11/05/2017 10:40 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mega Offline
Meteorological Motor Mouth

Registered: 03/02/2003
Posts: 6235
Loc: Maryborough, Wide Bay, QLD
Jamstec has backed off a bit too however it is still calling for a moderate Nino late in the year (about +1.5).

Check out the trades right now though, strong as ever:


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#1423110 - 11/05/2017 11:27 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 2488
Loc: Buderim
Three out of what I consider the top 4 models (EC, CFS, NASA, JMA) forecast moderate el nino. CFS being the odd one out with warm neutral, maybe borderline el nino.

EC and CFS seem to be showing a different trade wind pattern at 850hp to what TAO direct measurements are showing at the surface. TAO is showing moderate westerly anomalies still continuing just east of the dateline, where CFS and EC have had pretty much average trades over the last couple weeks. Where EC and CFS show stronger westerly activity in the far east, TAO direct obs shows near average. TAO also shows moderate warming in the central Pacific has happened in the last few days, and shows current conditions still as full steam towards moderate el nino. We'll see if the forecasts of EC and CFS for the next week or two change this. CFS is hinting at another round of westerlies in two weeks time, although weak, with weak easterly anomalies before and slightly stronger easterly anomalies after.

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#1423111 - 11/05/2017 11:31 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Locke Offline
Weatherzone Addict

Registered: 27/12/2007
Posts: 4256
Loc: Brisbane
The older forecasts are still showing moderate El Nino whilst the more recent forecasts are backing off.

Some of the CFS runs are certainly tending cooler now.

In the absence of any significant WWB incoming weeks I suspect all models will drop back to neutral to cool forecasts within a month.

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#1423166 - 12/05/2017 13:45 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
RC Offline
Weatherzone Addict

Registered: 29/09/2007
Posts: 1914
Loc: near Rockhampton, Qld
Bit of an update on this page on current events

http://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso_tab=enso-cpc_plume

Roughly a 50-50 chance of El Nino.

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#1423186 - 12/05/2017 19:50 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: RC]
Nature's Fury Offline
Weatherzone Addict

Registered: 29/11/2009
Posts: 1712
Loc: Brisbane Western Suburbs
Interesting article on ENSO, IPO and global temperature rises:

http://www.news.com.au/technology/enviro...9826f1c7ebef788

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#1423237 - 13/05/2017 15:54 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: Nature's Fury]
pete28 Offline
Weatherzone Addict

Registered: 08/01/2007
Posts: 1069
Loc: Christchurch, New Zealand
Originally Posted By: Nature's Fury
Interesting article on ENSO, IPO and global temperature rises:

http://www.news.com.au/technology/enviro...9826f1c7ebef788


Keep that man-made global warming propaganda to yourself please NF, the article has a large chunk devoted to pushing that particular cause

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#1423288 - 14/05/2017 12:54 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: pete28]
Nature's Fury Offline
Weatherzone Addict

Registered: 29/11/2009
Posts: 1712
Loc: Brisbane Western Suburbs
Originally Posted By: pete28
Originally Posted By: Nature's Fury
Interesting article on ENSO, IPO and global temperature rises:

http://www.news.com.au/technology/enviro...9826f1c7ebef788


Keep that man-made global warming propaganda to yourself please NF, the article has a large chunk devoted to pushing that particular cause


Really unnecessary response. Beside the fact that the article provides important information about ENSO-IPO interactions that are very relevant to this thread and the current weather situation, if you were unhappy with the article being posted there were other ways you could have responded instead of being obnoxious.

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#1423292 - 14/05/2017 13:47 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
pete28 Offline
Weatherzone Addict

Registered: 08/01/2007
Posts: 1069
Loc: Christchurch, New Zealand
I shouldn't have to point it out - the whole global warming discussion was shut down here remember - why are you trying to sneak it in again? It's quite obvious that the article was as much about man-made global warming then it was about El Niño etc

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#1423295 - 14/05/2017 14:08 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: pete28]
Nature's Fury Offline
Weatherzone Addict

Registered: 29/11/2009
Posts: 1712
Loc: Brisbane Western Suburbs
Originally Posted By: pete28
I shouldn't have to point it out - the whole global warming discussion was shut down here remember - why are you trying to sneak it in again? It's quite obvious that the article was as much about man-made global warming then it was about El Niño etc


This would have been a better post to make in the first place Pete instead of your highly emotional nonsense.

That doesn't change the fact that I disagree with your post. You say that I keep sneaking in climate change articles. Please point this out because I'm fairly sure I haven't done anything of the kind.

Also, are you saying that we shouldn't post articles if it has any mention of climate change? When it comes to longer-term climatic patterns, particularly decadal oscillations, climate change inevitably becomes mentioned. If you don't like the implications in the other half of the article then just ignore it or focus on the information that is less disagreeable to you. The ENSO/IPO info stands on its own regardless of your perspective on climate change and is highly relevant to this thread. I would have copy/pasted the ENSO/IPO sections and attached the images separately but that would have been pretty onerous and I didn't have the time.


Edited by Nature's Fury (14/05/2017 14:10)

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#1423318 - 14/05/2017 20:11 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
RC Offline
Weatherzone Addict

Registered: 29/09/2007
Posts: 1914
Loc: near Rockhampton, Qld
It is interesting looking at the CFS V2 Nino 3.4 prediction.

Where it is now compared to two months ago.

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#1423340 - 15/05/2017 08:53 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Chris Stumer Offline
Weatherzone Addict

Registered: 28/01/2010
Posts: 1492
Loc: Kingaroy
The Southern Oscillation Index has dropped to weak El Nino levels now, the question is will other indicators follow it into El Nino territory. The computer models are only reacting to the slow atmospheric response to the warming ocean.

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#1423362 - 15/05/2017 15:54 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
RC Offline
Weatherzone Addict

Registered: 29/09/2007
Posts: 1914
Loc: near Rockhampton, Qld
AAO looks to be reasonably positive these days.

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