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La Niña/Winter 2016-17 Discussion


dmillz25

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23 hours ago, snowman19 said:

Massive PDO drop continuing. Very dramatic when compared to just 2 months ago. This is the result of North Pacific High domination:anomnight.7.14.2016.gif

Not sure if it will hold up, but man is that the best SST configuration in the NATL for a -NAO in a dog's age.  If I recall correctly, the last 4-5 years the cold anaomalies have mostly hugged Iceland and Greenland vs being more south

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1 hour ago, SnowGoose69 said:

Not sure if it will hold up, but man is that the best SST configuration in the NATL for a -NAO in a dog's age.  If I recall correctly, the last 4-5 years the cold anaomalies have mostly hugged Iceland and Greenland vs being more south

Yeah I saw that too yesterday but forgot to post about it. That's a good look NAO speaking

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16 hours ago, SnowGoose69 said:

Not sure if it will hold up, but man is that the best SST configuration in the NATL for a -NAO in a dog's age.  If I recall correctly, the last 4-5 years the cold anaomalies have mostly hugged Iceland and Greenland vs being more south

I want to say 2013 maybe? It looked similar with a tripole around this same time of the year, but then by November, the NATL went ice cold again

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1 hour ago, Dsnowx53 said:

The CFS says the PDO will remain strongly positive, and that the Nina will be weak and central-east based. The trade winds might not be strong enough for a west-based Nina.

 

glbSSTSeaMaskInd5.gif

To my winter-weather-loving amateur eyes, that SST map looks strongly supportive of nice snows around here this winter, correct?

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7 hours ago, Dsnowx53 said:

The CFS says the PDO will remain strongly positive, and that the Nina will be weak and central-east based. The trade winds might not be strong enough for a west-based Nina.

 

glbSSTSeaMaskInd5.gif

This Niña is anything but east-based. In fact, it doesn't get more modoki looking than this: cdas-sflux_ssta_global_1.png Most models are trending strongly toward this being a modoki event: https://mobile.twitter.com/jnmet/status/753979623566958592

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2 hours ago, snowman19 said:

This Niña is anything but east-based. In fact, it doesn't get more modoki looking than this: cdas-sflux_ssta_global_1.png Most models are trending strongly toward this being a modoki event: https://mobile.twitter.com/jnmet/status/753979623566958592

To be fair, he was referring to the CFS and more specifically the DEC-FEB time frame. 

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3 hours ago, Rjay said:

To be fair, he was referring to the CFS and more specifically the DEC-FEB time frame. 

The CFS is so horrible and an outlier that it's not even worth looking at. It is so out to lunch and in a world all to its own, that yesterday, it was showing an El Niño developing

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Great explaination of what a La Niña Modoki is: 

- LA NINA MODOKI

Since 2007 a new type of La Niña was discovered from analysis of a Japanese team that have named it La Niña Modoki in Japanese. It is distinguished from the classic La Niña by its specific impact on the global atmospheric circulation. 

Traditionally, the classic La Niña is associated with the cooling in the eastern tropical Pacific (Niño 1+2 et 3). However, during La Niña Modoki the anomaly of the sea surface temperature (SST) in the eastern Pacific isn't affected by cooling but by warming just like western equatorial Pacific, while a cold anomaly affects the central equatorial Pacific (Niño 3.4). These zonal gradients of SST result in an anomaly in circulation of two Walker cells on the tropical Pacific, with a humid region in the Eastern and the Western Pacific. The thermocline doesn't switch the same way as during the classical La Niña because this one raises at the Eastern Equatorial Pacific to sink at the West while during its cousin the thermocline raises at the center of equatorial Pacific Ocean and sinks at each end of the Pacific.

La-Nina-modoki1.jpg
Comparison between the situation of Classic La Niña (a) and La Niña Modoki (b)

During the classic La Niña, the West Coast of the United States is dry but with La Niña Modoki it is rather humid. While during the Classic La Niña there is a significant increase in rainfall over the north and south of Australia, that the Modoki event seems to lead to a large-scale increase in the precipitations in the northwest and North Australia. India also would be affected by more precipitations with this second type of La Niña.

 

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11 hours ago, snowman19 said:
Great explaination of what a La Niña Modoki is: 

- LA NINA MODOKI

Since 2007 a new type of La Niña was discovered from analysis of a Japanese team that have named it La Niña Modoki in Japanese. It is distinguished from the classic La Niña by its specific impact on the global atmospheric circulation. 

Traditionally, the classic La Niña is associated with the cooling in the eastern tropical Pacific (Niño 1+2 et 3). However, during La Niña Modoki the anomaly of the sea surface temperature (SST) in the eastern Pacific isn't affected by cooling but by warming just like western equatorial Pacific, while a cold anomaly affects the central equatorial Pacific (Niño 3.4). These zonal gradients of SST result in an anomaly in circulation of two Walker cells on the tropical Pacific, with a humid region in the Eastern and the Western Pacific. The thermocline doesn't switch the same way as during the classical La Niña because this one raises at the Eastern Equatorial Pacific to sink at the West while during its cousin the thermocline raises at the center of equatorial Pacific Ocean and sinks at each end of the Pacific.

La-Nina-modoki1.jpg
Comparison between the situation of Classic La Niña (a) and La Niña Modoki (b)

During the classic La Niña, the West Coast of the United States is dry but with La Niña Modoki it is rather humid. While during the Classic La Niña there is a significant increase in rainfall over the north and south of Australia, that the Modoki event seems to lead to a large-scale increase in the precipitations in the northwest and North Australia. India also would be affected by more precipitations with this second type of La Niña.

 

With a Modoki La Nina, it looks like the US west coast (particularly California) will get much needed rain. 

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14 hours ago, SnowGoose69 said:

Wasn't 08-09 a Modoki La Nina?

 

14 hours ago, SnowGoose69 said:

Wasn't 08-09 a Modoki La Nina?

Yes. Over the last 20+ years the trend has been for modoki La Niña winters and not the classic east-based ones of the past

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8 minutes ago, snowman19 said:

The daily sst reading in region 3.4 is now below -1.0C, moderate: https://mobile.twitter.com/WxCoEnergy/status/757578663768522752

 

8 minutes ago, snowman19 said:

The daily sst reading in region 3.4 is now below -1.0C, moderate: https://mobile.twitter.com/WxCoEnergy/status/757578663768522752

Looks like a positive feedback loop has begun. This should sustain and strengthen the Niña from this point on...

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When you see strong trade winds sustain themselves like this and get more impressive with time, you have a positive feedback loop going for La Niña. Also, there appears to be the beginning of a standing wave in the IO which is another sign that the Niña is getting established: 

Michael Ventrice‏ @MJVentrice

Prolonged Pacific trade wind surge getting more and more impressive with time! Will boost Nina base state. https://mobile.twitter.com/MJVentrice/status/758979347147481088/photo/1

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1 hour ago, bluewave said:

Very confused pattern over the Pacific now where the La Nina is struggling to develop against the warm background +PDO state.

While the trades have picked up recently, the subsurface La Nina signature has weakened in recent months.

We have never seen a La Nina try to develop surrounded by such a sea of warm before.

Screen_Shot_2016_08_01_at_11_58_49_AM.png

 

sst.gif

 

Yeah, I find this very interesting, too. I expected the trade winds to have done more, but they really haven't. Subsurface cool anomalies have continued to get shallower and warmer. The trade winds are certainly not doing enough to make this a west-based Nina. It's going to either be a Modoki, or central/a tad east of central based Nina. I think you're right that the very warm background state of the Pacific is preventing the feedbacks from truly taking place.

 

It's not enough to just have some feedbacks going on in the Nino regions themselves; the feedbacks need to be happening in the whole Pacific, and I think the warm background state is preventing that from truly happening. This will not be a typical Nina, and it's looking like a pretty weak one.

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1 hour ago, bluewave said:

Very confused pattern over the Pacific now where the La Nina is struggling to develop against the warm background +PDO state.

While the trades have picked up recently, the subsurface La Nina signature has weakened in recent months.

We have never seen a La Nina try to develop surrounded by such a sea of warm before.

Screen_Shot_2016_08_01_at_11_58_49_AM.png

 

sst.gif

 

Yeah, I find this very interesting, too. I expected the trade winds to have done more, but they really haven't. Subsurface cool anomalies have continued to get shallower and warmer. The trade winds are certainly not doing enough to make this a west-based Nina. It's going to either be a Modoki, or central/a tad east of central based Nina. I think you're right that the very warm background state of the Pacific is preventing the feedbacks from truly taking place.

 

It's not enough to just have some feedbacks going on in the Nino regions themselves; the feedbacks need to be happening in the whole Pacific, and I think the warm background state is preventing that from truly happening. This will not be a typical Nina, and it's looking like a pretty weak one.

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On August 2, 2016 at 1:10 PM, Dsnowx53 said:

 

Yeah, I find this very interesting, too. I expected the trade winds to have done more, but they really haven't. Subsurface cool anomalies have continued to get shallower and warmer. The trade winds are certainly not doing enough to make this a west-based Nina. It's going to either be a Modoki, or central/a tad east of central based Nina. I think you're right that the very warm background state of the Pacific is preventing the feedbacks from truly taking place.

 

It's not enough to just have some feedbacks going on in the Nino regions themselves; the feedbacks need to be happening in the whole Pacific, and I think the warm background state is preventing that from truly happening. This will not be a typical Nina, and it's looking like a pretty weak one.

The strong trades have not even had a chance to really kick in yet and the Niña is already having a profound effect on the atmospheric pattern, look at the AAM. It's gone very negative. The coupling has already begun on the long wave pattern. The positive feedback loop has started.  Very strong trades projected on the models throughout this month. As far as this event not being a modoki, it can't possibly get more modoki looking than it is right now. This is anything but an east based Niña, in fact the exact opposite. Make no mistake about it, there will be a La Niña. Btw, the weekly readings have hit Niña status in region 3.4

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