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#1465703 - 15/06/2018 21:38 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: RC]
snowbooby Offline
Weather Freak

Registered: 11/05/2016
Posts: 275
Originally Posted By: RC
Looking at the current forecast wind anomaly maps. It dawned on me the maps do not indicate wind direction but rather whether the winds will be stronger or weaker then the long term average.

So if the normal wind direction is 6m/s from South America to Asia direction, and there is an anomaly forecast of -3m/s, that means the winds will still blow from South America to Asia, just only at 3m/s speed.


Dont know which anomaly mapping you are looking at so not certain how it should be interpreted.

Often hovmoller charts of equatorial winds (and anomalies) follow the convention of an east-west component wind. Easterly winds(in this case the trades) are given -ve sign. The same convention is used with QBO data also(though this data is obs of wind speed and not anomalies).

Since the mean state of enso region winds is easterly, anomalies which are also depicted by -ve sign (and usually shades of blue through to magenta on the charts themselves) are directly proportional to the size of the anomaly value and represent an easterly wind - so an anomaly of -11 represents a stronger easterly than -4.

The +ve westerly component(usually starting in shades of greenish yellow through to red) represents a weakening of the mean state(and, at some point, an actual westerly).


With the above in mind, I think if the mean state was 6m/s(easterly), an anomaly of -3 would represent a mild strengthening of that wind though rather than a weakening.

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#1465792 - 17/06/2018 09:06 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Chris Stumer Offline
Weatherzone Addict

Registered: 28/01/2010
Posts: 1883
Loc: Kingaroy
NOAA are on El Nino watch now.

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#1465815 - 17/06/2018 14:41 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
RC Offline
Weatherzone Addict

Registered: 29/09/2007
Posts: 2601
Loc: near Rockhampton, Qld
Hopefully that will mean it will rain.

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#1465954 - 18/06/2018 20:30 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Flowin Offline
Weather Freak

Registered: 15/10/2017
Posts: 966
Loc: Pinjarra Hills, Qld
It appears to me much of the climate driver discussion is heat or temperature of the ocean and effect on temps of water / air and what that drives the dynamics of air and water movements.... And feedback to stored heat in water.
Or, is there something else at play?
assuming land is a slow heat flux.
N.B. This isa totally exploratory question to clarify understanding not a statement of fact. Corrections welcome
_________________________
Models are for estimating and gauges are for knowledge.

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#1465957 - 18/06/2018 21:17 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Flowin Offline
Weather Freak

Registered: 15/10/2017
Posts: 966
Loc: Pinjarra Hills, Qld
Correction. I meant "assuming land is a small heat flux"
_________________________
Models are for estimating and gauges are for knowledge.

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#1465977 - 19/06/2018 07:55 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: Chris Stumer]
retired weather man Offline
Meteorological Motor Mouth

Registered: 01/07/2007
Posts: 5161
Loc: Wynnum
Originally Posted By: Chris Stumer
NOAA are on El Nino watch now.


As has happened the past few El Ninos, the drier weather locally seems to have preceded the official readngs that determine an El Nino.

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#1465988 - 19/06/2018 10:03 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Petros Offline
Meteorological Motor Mouth

Registered: 30/12/2002
Posts: 8071
Loc: Maffra, Central Gippsland, Vi...
For my 2 bobs, the sea temps surrounding Aus atm are still warm enough to promote wet weather for at least 3 more weeks or so - given the right triggers (MJO/AAO).

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#1465997 - 19/06/2018 11:10 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: retired weather man]
Locke Offline
Weatherzone Addict

Registered: 27/12/2007
Posts: 4553
Loc: Brisbane
Originally Posted By: retired weather man
Originally Posted By: Chris Stumer
NOAA are on El Nino watch now.


As has happened the past few El Ninos, the drier weather locally seems to have preceded the official readngs that determine an El Nino.


Absolutely.

Widespread drier anomalies for the past 3 months do look like a precursor to a developing El Nino.
_________________________
This post and any other post by Locke is NOT an official forecast & should not be used as such. It's just my opinion & may or may not be backed by sound meteorological data. For official information, refer to Australian Bureau of Meteorology products.

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#1466010 - 19/06/2018 13:45 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 3817
Loc: Buderim
Current SSTs definitely seem to be colder near Australia, and warmer near the dateline. Solid pattern for moving tropical moisture away from Australia and out into the Pacific ocean. Significant cold blob to our NW in the Indian at the moment as well. One thing is that the Indian Ocean overall is on the cooler side (compared to recent years) and I have read somewhere that its not only the IOD that has been contributing to recent droughts, but overall warm, so presumably overall cool Indian might be good.

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#1466016 - 19/06/2018 14:27 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
RC Offline
Weatherzone Addict

Registered: 29/09/2007
Posts: 2601
Loc: near Rockhampton, Qld
I am not convinced yet. The warming may have peaked or be close to peaking.

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#1466025 - 19/06/2018 15:53 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Thunderstruck Offline
Lightning man

Registered: 10/05/2001
Posts: 15024
Loc: Seaford Meadows, SA
Negative IOD thresholds reached for the monthly now...brief cool blob will push it back to neutral territory before things warm up again.

TS cool

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#1466026 - 19/06/2018 15:53 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
KevD Offline
Occasional Visitor

Registered: 23/09/2001
Posts: 5236
Loc: Bellingen NSW 2454
From the latest BoM outlook:
Current status: El Niño WATCH
The El Niño–Southern Oscillation (ENSO) remains neutral. However, latest model outlooks and recent warming in the tropical Pacific Ocean indicates that the chance of El Niño forming in spring has increased. As a result, the Bureau's ENSO Outlook status has moved to El Niño WATCH. El Niño WATCH means the likelihood of El Niño forming in 2018 is approximately 50%; double the normal chance.

Oceanic indicators are currently neutral—neither El Niño nor La Niña—but show some signs of potential El Niño development. Sea surface temperatures in the eastern Pacific Ocean, though currently neutral, have been slowly warming since April. Importantly, waters below the surface of the tropical Pacific are now warmer than average—a common precursor to El Niño.

The majority of international climate models surveyed by the Bureau forecast the tropical Pacific Ocean will continue to warm but stay in the neutral range during July and August. However, five of eight models indicate the ocean warmth is likely to reach El Niño thresholds in the southern hemisphere spring, while a sixth model falls just short.

During El Niño, rainfall in eastern Australian is typically below average during winter and spring. A neutral ENSO phase has little effect on Australian climate.

The Indian Ocean Dipole (IOD) remains neutral. Five of six climate models indicate the IOD is likely to remain neutral in the coming months, and one model suggests a positive IOD.

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#1466028 - 19/06/2018 16:08 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Kino Offline
Weatherzone Addict

Registered: 10/08/2017
Posts: 3505
Loc: Wollongong, NSW, Aus
Amazing how quickly they are to jump to an El Niño watch....yet last season didn’t move to a La Niña watch until La Niña had already formed.

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#1466032 - 19/06/2018 16:31 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: Kino]
Funkyseefunkydo Offline
Weather Freak

Registered: 30/04/2007
Posts: 906
Loc: East Lake Macquarie
Originally Posted By: Kino
Amazing how quickly they are to jump to an El Niño watch....yet last season didn’t move to a La Niña watch until La Niña had already formed.
I see your point. But is it not easier for an elnino to establish rather than an LaNina historically? It’s also just a watch. Not declaring anything.

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#1466043 - 19/06/2018 17:26 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
retired weather man Offline
Meteorological Motor Mouth

Registered: 01/07/2007
Posts: 5161
Loc: Wynnum
And last time, the El Nino locally was well under way for about 6 months under a watch before it was officially declared.

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#1466044 - 19/06/2018 17:28 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: retired weather man]
Kino Offline
Weatherzone Addict

Registered: 10/08/2017
Posts: 3505
Loc: Wollongong, NSW, Aus
Originally Posted By: retired weather man
And last time, the El Nino locally was well under way for about 6 months under a watch before it was officially declared.


Hardly the same - least a “watch”had been issued - the La Niña had been declared and our BoM was at defcon Neutral.

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#1466056 - 19/06/2018 18:14 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 3817
Loc: Buderim
Its because of the conspiracy.

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#1466058 - 19/06/2018 18:20 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
scott12 Offline
Weatherzone Addict

Registered: 10/11/2015
Posts: 1231
Loc: maadi Tully area
LOL

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#1466059 - 19/06/2018 18:20 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: Mike Hauber]
Petros Offline
Meteorological Motor Mouth

Registered: 30/12/2002
Posts: 8071
Loc: Maffra, Central Gippsland, Vi...
Originally Posted By: Mike Hauber
Its because of the conspiracy.


smile debate is good!

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#1466061 - 19/06/2018 18:29 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: Petros]
Kino Offline
Weatherzone Addict

Registered: 10/08/2017
Posts: 3505
Loc: Wollongong, NSW, Aus
Originally Posted By: Petros
Originally Posted By: Mike Hauber
Its because of the conspiracy.


smile debate is good!


Still waiting for that El Niño Mike....there’s your conspiracy.

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