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#1399885 - 02/01/2017 06:43 Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc)
ColdFront Offline
Meteorological Motor Mouth

Registered: 29/06/2008
Posts: 17913
Loc: Wide Bay..Near the beach
Discussion continues.

Welcome to 2017 and Happy New Year. Hopefully a wet one for those that need it.
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#1399887 - 02/01/2017 07:30 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
NotsohopefulPete Offline
Weatherzone Addict

Registered: 24/12/2008
Posts: 1087
Loc: Toowoomba
From Weatherunderground
Looking Ahead to 2017:
What to Watch For, Weather- and Climate-Wise
By: Bob Henson , 1:51 PM GMT on December 30, 2016


Between a record-strong El Niño and catastrophic floods, fires, and drought, 2016 was a memorable year for weather and climate in North America as well as globally. What can we expect as we roll into 2017? A precise weather forecast is asking too much, but there is already a lot we can say about some key factors. Here are six developments to watch for in 2017. They’re presented in rough order of increasing confidence, followed by details on each prediction.

1. Better odds of El Niño than La Niña, but a neutral Pacific still favored


1. Better odds of El Niño than La Niña, but a neutral Pacific still favored
The biggest single driver of year-to-year atmospheric variations around the globe is the El Niño–Southern Oscillation (ENSO), including El Niño and its counterpart, La Niña. A year ago, it was virtually certain that the record-strong El Niño of 2015-16 would continue through at least the first few months of 2016, as it indeed did. This time around, the ENSO signal is far less clear-cut. Sea surface temperatures (SSTs) in the benchmark Niño3.4 region of the eastern tropical Pacific have been inconclusive in recent months, hovering close to the La Niña threshold (at least -0.5°C below the seasonal average) since late July.


Figure 1. Departures from average sea surface temperature for this time of year as of mid-December show a diffuse, borderline La Niña signal across the central and eastern tropical Pacific. Image credit: NOAA Climate Prediction Center.

It’s now become less likely that the ocean and atmosphere will commit to a well-defined La Niña event for early 2017. There’s almost no telling what will happen later in the year, on the other side of the infamous “spring predictability barrier” that often separates one El Niño or La Niña event from another. One clue we do have is the unusual persistence this year of a belt of warmer-than-average SSTs from the central tropical Pacific to the west coast of North America. This warm phase of what’s called the Pacific Meridional Mode may herald a new El Niño event in 2017-18, as niftily explained by Dan Vimont (University of Wisconsin Center for Climatic Research) in a recent climate.gov post.

In their joint probabilistic outlook issued in early December, NOAA’s Climate Prediction Center (CPC) and the International Research Institute for Climate and Society (IRI) called for decreasing odds of La Niña over the next few months, dropping to just 18% by late spring. Neutral conditions are deemed most likely by CPC/IRI, with 65% odds by spring and 53% by summer. And the odds of El Niño are expected to steadily rise throughout the first half of 2017, reaching 29% by summer. Strong El Niño events like the one we just had are usually followed by a significant La Niña event. If the atmosphere instead ends up cueing El Niño for 2017-18, it would reinforce the notion that we’ve entered a positive phase of the Pacific Decadal Oscillation--a sign that we might expect more El Niño than La Niña events for as long as a decade or two.


Figure 2. Probabilities of El Niño (red), La Niña (blue), and neutral conditions (green), for each overlapping three-month period from November-January 2016-17 (left) to July-September 2017 (right). These probabilities are set each month by forecasters from NOAA’s Climate Prediction Center and the International Research Institute for Climate and Society. Image credit: NOAA/IRI.


Edited by Hopefull (02/01/2017 07:31)

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#1399906 - 02/01/2017 09:01 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Chris Stumer Offline
Weatherzone Addict

Registered: 28/01/2010
Posts: 1609
Loc: Kingaroy
Perhaps we could see a La Nina this year after all the 2015-2016 El Nino was preceeded by a strong warm neutral in 2014-2015, so one has to wonder if El Nino can do it, then La Nina could do it as well.

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#1399921 - 02/01/2017 09:51 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
greg.l Offline
Weather Freak

Registered: 01/09/2016
Posts: 335
Loc: north of bathurst NSW
12/13, 14/15 and 15/16 were all enso negative years with only 15/16 progressing to full blown el nino. You would have to think that 17/18 will probably be enso negative but maybe not full el nino. The El nino of 15/16 didn't produce very strong effects in SE Aust anyway, they don't seem to have the impact they used to.

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#1399923 - 02/01/2017 09:57 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
mammatus meestrus Offline
Cloud Gazer

Registered: 20/11/2008
Posts: 40
Loc: lennox head
1225mm rainfall for Ballina 2016.
Yearly average 1817.9.

Minus the June Black nor-easter event and it sure felt like a Nino year here. Very noticeable absence of pacific moisture.

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#1399937 - 02/01/2017 10:37 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mike Hauber Offline
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Registered: 13/07/2007
Posts: 2755
Loc: Buderim
Sub surface for most of the Pacific has warmed a lot in the last couple months. La Nina seems quite unlikely now.

Its a bit of a mystery as it looks a lot like a substantial Kelvin wave has progressed across the Pacific, but there is no westerly activity I can see to kick it off. While we have had some westerly activity, it has been too far east to kick of such a wave as far as I understand.

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#1399956 - 02/01/2017 11:32 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
_Johnno_ Offline
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Registered: 08/11/2009
Posts: 1694
A sustained period of strong easterlies to come through the next week or so, the strongest and most sustained yet since the demise of El Nino


Edited by _Johnno_ (02/01/2017 11:32)
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#1400069 - 02/01/2017 17:22 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mega Offline
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Registered: 03/02/2003
Posts: 6621
Loc: Maryborough, Wide Bay, QLD
Looks like the SAM (this one http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/aao/new.aao_index_ensm.html, to cover all bases) is forecast to stay strongly negative for another few weeks. Sigh. Every time it looks like going positive it dips back into negative.

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#1400117 - 02/01/2017 18:57 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Chris Stumer Offline
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Registered: 28/01/2010
Posts: 1609
Loc: Kingaroy
Could a persistently negative SAM help trigger an El Nino event I wonder?

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#1400289 - 03/01/2017 10:16 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: Mike Hauber]
snowbooby Offline
Weather Freak

Registered: 11/05/2016
Posts: 108
Originally Posted By: Mike Hauber

Its a bit of a mystery as it looks a lot like a substantial Kelvin wave has progressed across the Pacific, but there is no westerly activity I can see to kick it off. While we have had some westerly activity, it has been too far east to kick of such a wave as far as I understand.


...possibility of involvement of rossby wave reflection on western boundary?

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#1400307 - 03/01/2017 11:38 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: mammatus meestrus]
ozthunder Offline
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Registered: 23/09/2001
Posts: 3021
Loc: Mt Warrigal, NSW, Australia
Originally Posted By: mammatus meestrus
1225mm rainfall for Ballina 2016.
Yearly average 1817.9.

Minus the June Black nor-easter event and it sure felt like a Nino year here. Very noticeable absence of pacific moisture.


Very dry in Illawarra.

As an astute Weatherzone member mentioned in another forum area, between 30-40% of our annual rain tally fell in June, and most of that with a single ECL event.

Without that it would be near record dry territory.
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#1400308 - 03/01/2017 11:39 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Wave Rider Offline
Meteorological Motor Mouth

Registered: 27/01/2014
Posts: 6438
Loc: Wollongong and Berrima NSW
Originally Posted By: greg.l
The El nino of 15/16 didn't produce very strong effects in SE Aust anyway, they don't seem to have the impact they used to.


I agree and in fact 2016 was hardly influenced by ENSO but more so by the negative IOD and the negative SAM. If the negative SAM continues we should expect a bumper snow season on the Alps. That's why I like that this since last year this thread is no longer called ENSO discussion, but rather it takes into account all our climate drivers.

Yes Michael, without the ECL we'd possibly be around 500mm or at least under 600mm for the year which would be unheard of here.
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#1400313 - 03/01/2017 12:15 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Funkyseefunkydo Offline
Weather Freak

Registered: 30/04/2007
Posts: 487
Loc: East Lake Macquarie
Nice Animation of precipitale water from earth nullschool. Can see those NW feeds.

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#1400595 - 05/01/2017 09:02 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Funkyseefunkydo Offline
Weather Freak

Registered: 30/04/2007
Posts: 487
Loc: East Lake Macquarie
Does this monsoon look to be driven by the lanina.? CFS has it hanging over Qld all month.

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#1400649 - 05/01/2017 13:33 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mega Offline
Meteorological Motor Mouth

Registered: 03/02/2003
Posts: 6621
Loc: Maryborough, Wide Bay, QLD
Jeez how juicy are those easterlies across the Pacific currently? They're even pushing into the WPAC as well. GFS long range shows a really strong monsoonal pulse coming up in about 2 weeks time though which looks like it might trigger a WWB in the WPAC. Will be interesting to see, if that does happen, what happens following it (possible Kelvin Wave development?)

Closer to home though it sucks to see a continuation of this annoying pattern with high pressure systems moving across Victoria then darting north through that NZ / NSW coast corridor. This is SAM related, right? Even if you look at EC's 500mb height + mslp chart you can see NZ smothered by trough systems for the foreseeable period with highs stuck to the NW. Not really ideal for coastal parts of Queensland / NE NSW and can't be a coincidence that many of those places have received well below average rainfall for spring and so far summer despite being in a cool- neutral ENSO phase.

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#1400653 - 05/01/2017 13:45 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
RC Offline
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Registered: 29/09/2007
Posts: 2085
Loc: near Rockhampton, Qld
Also Mega, there is not a lot of time left for a decent wet season for your area and up the coastline. BOM already said January would have a low chance of above average rainfall. February only slightly better.

Along with hushed talks of this year having a higher chance of El Nino yet again, along with hushed talks of the PDO moving to a dryer phase. And the SAM also playing havoc with the rain chances of coastal Qld.

I think I will be preparing for a dry year yet again. Although we are still feeding from last year which is a very rare occurrence for us. This year could end up very nasty indeed.

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#1400693 - 05/01/2017 18:09 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Chris Stumer Offline
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Registered: 28/01/2010
Posts: 1609
Loc: Kingaroy
All it takes is one system to put a dry season above average, we saw that with Oswald back in 2013.

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#1400794 - 06/01/2017 08:35 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: RC]
retired weather man Offline
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Registered: 01/07/2007
Posts: 4328
Loc: Wynnum
Plus the continuing cyclic decline in solar activity which over the past 50 years seems to mirror excessive El Nino occurrences.


Originally Posted By: RC
Also Mega, there is not a lot of time left for a decent wet season for your area and up the coastline. BOM already said January would have a low chance of above average rainfall. February only slightly better.

Along with hushed talks of this year having a higher chance of El Nino yet again, along with hushed talks of the PDO moving to a dryer phase. And the SAM also playing havoc with the rain chances of coastal Qld.

I think I will be preparing for a dry year yet again. Although we are still feeding from last year which is a very rare occurrence for us. This year could end up very nasty indeed.
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#1400817 - 06/01/2017 11:46 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Chris Stumer Offline
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Registered: 28/01/2010
Posts: 1609
Loc: Kingaroy
The SAM can't stay negative forever, sooner or later it will go positive and that's when we'll cop it.

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#1400833 - 06/01/2017 14:42 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
_Johnno_ Offline
Weatherzone Addict

Registered: 08/11/2009
Posts: 1694
I mentioned it last week the predicted stronger easterlies shown by the models Mega but no one seemed to take any interest

Happy new year folks.

Has the PDO switched back to cool? That big pool of cooler than normal ssts in the North Pacific has expanded eastwards to the west coast of the US now.


http://weather.unisys.com/surface/sst_anom.gif


By the way models going for a sustained period of strong easterlies winds across western and central Pacific Equator from mid next week onwards... Strongest sustained easterlies I have seen yet that the models have predicted since the El Nino ended.



Edited by _Johnno_ (06/01/2017 14:43)
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