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#1430288 - 09/08/2017 21:34 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
adon Offline
Meteorological Motor Mouth

Registered: 19/08/2004
Posts: 5295
Loc: Not tellin!
As John pointed out to me, the Indian Ocean cold spot has lost some sting and moved west a bit. I'm thinking there must be strong surface warming there but any type of system going past stirs up the deeper cold water. It would be handy to have a TAO style buoy out there to see the story underwater

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#1430309 - 10/08/2017 09:02 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: adon]
Mike Hauber Offline
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Registered: 13/07/2007
Posts: 2605
Loc: Buderim
Originally Posted By: adon
If it does go to La Niña, it will make a mockery of the models most of them had us burning in hell by now! ( yes I know that's not right but they were all going for at least a moderate Elnino.

If this comes off, maybe it's time to look at the drivers and assumptions being used to come up with these "predictions"

What do you think Mike????


A surprising amount of cooling given a trade wind burst weaker than the one in March which was only a short term slow down in the overall warming trend.

Warm water still almost everywhere except along the central equatorial region. It is also warm at and below the surface near the dateline, warm water in this region is a key driver for increased WWB activity (which has been very weak this year). I think warm side of neutral is still more likely for the rest of the year, La Nina is out of the question, and a significant sustained burst of cool neutral possible, but not what I'm expecting.

The models were not going for at least a moderate el nino, but more like on average of moderate el nino with a range from warm neutral to extreme.

The current 30 day GFS forecast suggests some quite strong westerly anomalies coming up. We'll have to see whether this actually happens and what the impact is if it does.

From late last year to a momth ago we have seen steady warming despite rather weak westerly anomalies. I had thought that this may be due to weak tropical activity and low cloudiness allowing increasing solar heating, but as far as I can tell this hasn't changed. Perhaps some other factor was causing more warming than the trade wind anomalies might otherwise suggest, and has now switched. Or maybe factors such as the Pacific being more or less sensitive to trade wind changes at different times of year - more sensitive now as this is when ENSO events usually go into a positive feedback loop.

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#1430347 - 10/08/2017 15:40 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Kino Online   content
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Registered: 10/08/2017
Posts: 664
Loc: Wollongong, NSW, Aus
Interesting model take on our summer - decent La Nina wedged between a moderate +IOD. Those east coast SST's surely should help with some much needed sky-water? Sure is a big change from heat, heat and more heat model takes lately.


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#1430350 - 10/08/2017 15:55 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Kino Online   content
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Registered: 10/08/2017
Posts: 664
Loc: Wollongong, NSW, Aus
And to add, that model seems to indicate a decent monsoon too, as you can see the heat content being stripped out of the South China sea from Nov --> March (goes from +1~ above average to -1 or more below).

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#1430429 - 11/08/2017 14:47 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mega Offline
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Registered: 03/02/2003
Posts: 6453
Loc: Maryborough, Wide Bay, QLD
Check out the subsurface, juicy cold anoms building again through the CPAC & EPAC: http://www.bom.gov.au/cgi-bin/wrap_fwo.pl?IDYOC007.gif

However there appears to be a drop off in trade winds over the next couple of weeks so I'm not convinced they will continue to grow.

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#1430430 - 11/08/2017 15:04 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: Mega]
Kino Online   content
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Registered: 10/08/2017
Posts: 664
Loc: Wollongong, NSW, Aus
Originally Posted By: Mega
Check out the subsurface, juicy cold anoms building again through the CPAC & EPAC: http://www.bom.gov.au/cgi-bin/wrap_fwo.pl?IDYOC007.gif

However there appears to be a drop off in trade winds over the next couple of weeks so I'm not convinced they will continue to grow.


Seems to be something else in play? Previous trades didn't really aide cooling hey. Some serious upwelling going on, and NCEP looks juicy. Hope to comes off, should be a big wet summer for eastern Aus, western Aus will be very hot and dry.

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#1430435 - 11/08/2017 15:33 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
ColdFront Offline
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Registered: 29/06/2008
Posts: 17703
Loc: Wide Bay..Near the beach
The breakdown in the central pacific equatorial warm anomalies has been quite rapid in the top 100 metres .

Animation
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#1430436 - 11/08/2017 15:38 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Kino Online   content
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Registered: 10/08/2017
Posts: 664
Loc: Wollongong, NSW, Aus
Originally Posted By: ColdFront
The breakdown in the central pacific equatorial warm anomalies has been quite rapid in the top 100 metres .

Animation


Yeah some major upwelling happening - check out that area 120w - 100w - like a HUGE long wave trough passing by.

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#1430524 - 13/08/2017 07:26 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mike Hauber Offline
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Registered: 13/07/2007
Posts: 2605
Loc: Buderim
Starting to think that a cool Kelvin wave has been generated, which might eplain at least in part the stronger cooling compared to the march trade wind burst. The current burst was an abrupt switch from weak westerly anomalies, which may have been much more effective in wave generation than the march event following from weak easterly anomalies. If so some of the cooling may disappear quickly once the Kelvin wave runs its course if not followed up by further enhanced trade wind activity.

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#1430525 - 13/08/2017 07:37 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Funkyseefunkydo Online   content
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Registered: 30/04/2007
Posts: 468
Loc: East Lake Macquarie
I've noticed a coming shift in the weather pattern after this big low moves through. Looks as though a trough to set up over or off WA coast. Also those persistent easterly winds have stopped between indo and Australia.

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#1430531 - 13/08/2017 10:47 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Chris Stumer Offline
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Registered: 28/01/2010
Posts: 1545
Loc: Kingaroy
This winter heatwave could be an indicator of a wet summer ahead because it's similar to 2009 and then it turned very wet in December of that year. Once the cold water starts upwelling the atmosphere should start to couple with it.

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#1430532 - 13/08/2017 10:56 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: Mike Hauber]
Kino Online   content
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Registered: 10/08/2017
Posts: 664
Loc: Wollongong, NSW, Aus
Originally Posted By: Mike Hauber
Starting to think that a cool Kelvin wave has been generated, which might eplain at least in part the stronger cooling compared to the march trade wind burst. The current burst was an abrupt switch from weak westerly anomalies, which may have been much more effective in wave generation than the march event following from weak easterly anomalies. If so some of the cooling may disappear quickly once the Kelvin wave runs its course if not followed up by further enhanced trade wind activity.


NCEP totally disagrees with you, instead ramping up the cooling across all Nino areas.

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#1430533 - 13/08/2017 11:28 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mega Offline
Meteorological Motor Mouth

Registered: 03/02/2003
Posts: 6453
Loc: Maryborough, Wide Bay, QLD
Interesting that Jamstec seasonal page has been down for a while now, wonder if Typhoon Noru knocked out the server or something.

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#1430678 - 14/08/2017 20:41 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Funkyseefunkydo Online   content
Weather Freak

Registered: 30/04/2007
Posts: 468
Loc: East Lake Macquarie
Michael Ventrice:
Globally averaged atmospheric angular momentum is forecast to drop below -1 sigma, the lowest state of 2017 thus far. La Nina atmosphere

🤔

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#1430708 - 14/08/2017 23:41 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
_Johnno_ Offline
Weatherzone Addict

Registered: 08/11/2009
Posts: 1653
Going by NOAA

NINO 3.4 temps

July 31st 0.0c
Aug 7th 0.2c
Aug 14th -0.2c
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#1430711 - 15/08/2017 07:39 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: Kino]
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 2605
Loc: Buderim
Originally Posted By: Kino
Originally Posted By: Mike Hauber
Starting to think that a cool Kelvin wave has been generated, which might eplain at least in part the stronger cooling compared to the march trade wind burst. The current burst was an abrupt switch from weak westerly anomalies, which may have been much more effective in wave generation than the march event following from weak easterly anomalies. If so some of the cooling may disappear quickly once the Kelvin wave runs its course if not followed up by further enhanced trade wind activity.


NCEP totally disagrees with you, instead ramping up the cooling across all Nino areas.


Clear evidence now of a cool kelvin wave now in TAO TRITON with the western edge of the subsurface cool pool weakening and extending and strengthening towards the east.

Recent westerly anomalies in the far west might not look like much, but similar anomalies produced a kelvin wave earlier this year. The arrival of this kelvin wave in the far east coincided with a further burst of westerly anomalies in that region and generated a strong and rapid warming. Current 30 day CFS forecast is for substantial westerly anomalies in the central pacific for most of the forecast period, which looks to coincide with a positive kelvin wave and could produce quite substantial warming in the central pacific. Wouldn't be as extreme an effect as in the far east as subsurface temp gradients are strongest in the far east, so kelvin wave generated changes in upwelling have the biggest effect.

NCEP/CFS does seem to pick this up with the most recent model runs showing warming for September, before cooling resumes. Presumably CFS is expecting stronger trade wind bursts to follow on from its forecast westerly anomalies in the next 30 days.

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#1430786 - 15/08/2017 16:01 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Kino Online   content
Weather Freak

Registered: 10/08/2017
Posts: 664
Loc: Wollongong, NSW, Aus
Latest BoM outlook - Neutral ENSO & IOD conditions to persist til end of year

The El Niño—Southern Oscillation (ENSO) is currently neutral. All international climate models surveyed by the Bureau suggest the tropical Pacific Ocean is likely to stay ENSO neutral for the remainder of 2017.

Sea surface temperatures (SSTs) have cooled over much of the central tropical Pacific during the past four weeks, and are now close to the long-term average, and within the neutral range. The 30-day Southern Oscillation Index (SOI) also remains neutral, having steadied over the past three weeks. Other indicators of ENSO, such as cloudiness near the Date Line and trade winds are also at neutral levels.

The Indian Ocean Dipole (IOD) also remains neutral with consensus amongst climate models suggesting neutral conditions are likely to persist. Some models suggest positive IOD thresholds could be reached in the coming months but these values are unlikely to be sustained long enough to classify as a positive IOD event. Positive IOD events are typically associated with below average winter and spring rainfall over central and southern Australia.

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#1430919 - 16/08/2017 14:57 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mega Offline
Meteorological Motor Mouth

Registered: 03/02/2003
Posts: 6453
Loc: Maryborough, Wide Bay, QLD
A couple more tweets for those who don't follow social media:

https://twitter.com/BenNollWeather/status/897407697435336705
https://twitter.com/BenNollWeather/status/897408354011627520

Basically shows the JMA model dipping further into La-Nina levels for summer.

Also, August ECMWF is out and is clearly dipping further into cool levels too. July run had most members still at warm-neutral levels by September, August run has all members at neutral or slightly below all of a sudden. It is playing massive catchup. Have to hand it to CFS for being one of the first models to predict this cooling since Autumn.

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#1430920 - 16/08/2017 15:59 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: Mega]
Kino Online   content
Weather Freak

Registered: 10/08/2017
Posts: 664
Loc: Wollongong, NSW, Aus
Originally Posted By: Mega
A couple more tweets for those who don't follow social media:

https://twitter.com/BenNollWeather/status/897407697435336705
https://twitter.com/BenNollWeather/status/897408354011627520

Basically shows the JMA model dipping further into La-Nina levels for summer.

Also, August ECMWF is out and is clearly dipping further into cool levels too. July run had most members still at warm-neutral levels by September, August run has all members at neutral or slightly below all of a sudden. It is playing massive catchup. Have to hand it to CFS for being one of the first models to predict this cooling since Autumn.


Makes me wonder what "models" the BoM surveyed for it's outlook. NCEP, EC & JMA all cooling. Not many left lol

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#1430937 - 16/08/2017 20:27 Re: Climate Driver Discussion 2017 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
_Johnno_ Offline
Weatherzone Addict

Registered: 08/11/2009
Posts: 1653
I think POAMA was one of the first models to show cool neutral Mega but I may be wrong.

UKMET also cooler, into cool neutral territory now in its latest August update.
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