La Niña/Winter 2016-17 Discussion

[PB GFI]

1 hour ago, Morris said:

And NOAA's new forecast has our area as EC for the winter in a sea of warmth.

 

A sea of warmth ?  

Can you post that please. I am curious to see what you are referring too .

[EasternLI]

5 minutes ago, PB GFI said:

 

? 

Can you post that please. I am curious to see what you are referring too .

 

It's equal chances...

 

[PB GFI]

3 minutes ago, EasternLI said:

 

It's equal chances...

 

 

lol,  I know.  N ish from NOAA is decent look. 

NOAA centers the cold from Manitoba on S into the UMW.

 

My Center point is East into the  GL.

 

Decent SW and W ridging there too. 

 

 

[EasternLI]

Judah Cohen's blog update today is a fun read. 

 

https://www.aer.com/science-research/climate-weather/arctic-oscillation

 

I don't know, looking at this AO behavior, I think I'm leaning for it to avg neg for the winter. The Pacific is really going to decide how this year plays out I think. If it's favorable, could be really good.

 

Quote

The impact of the predicted near record WAFz pulse can be seen in the stratospheric AO forecast, which shows the stratospheric AO dropping into near record low territory in late October and early November (Figure 1).   If the GFS forecast of a fully coupled weak stratospheric and tropospheric PV and a negative AO both in the stratosphere and the troposphere would likely result in an early start to winter across widespread regions of the Northern Hemisphere mid-latitudes.  The regions mostly likely to experience an early winter chill include Siberia and East Asia.  However there has been a tendency for the blocking near the Urals to be further north relative to last winter and the tendency for the NAO to be negative, therefore I feel this increases the probability of the cold air in Siberia flowing west into Europe as well.   The Eastern US is a tougher call and would also depend on the circulation in the eastern North Pacific where troughing/negative geopotential height anomalies would favor the Eastern US remaining warm while ridging/positive geopotential height anomalies would favor colder temperatures in the Eastern US.

 

[Stebo]

4 hours ago, WEATHERBUFF said:

I see your point and some may disagree I'm sure, but where I live 2007-08 winter was'nt bad snowfall wise. While it was a little bit above normal, snowfall was around normal for northeast Pa. I don't believe this year has anthing in common with 2011-2012 which even then we saw more snow than last year for us

I only mentioned 2011-12 as to what could go wrong with the EPO. This winter is nothing like that winter, it was merely just a talking point about what could go wrong if an index goes unfavorable.

[Stebo]

2 hours ago, Isotherm said:

 

I see much discussion of 13/14 floating around, but I think it will be difficult to achieve that type of robust, protracted -EPO ridging this winter. Still early for me, but I'm not sold on significant  blocking in any high latitude domain just yet.

Agreed, there should be bouts of -EPO this winter but if the ridging forms more in the Aleutians or Western Alaska, it would hard to get much -EPO action through the winter. The PDO flipping to negative also hurts the chances of prolonged -EPO.

[snowman19]

18 minutes ago, Stebo said:

Agreed, there should be bouts of -EPO this winter but if the ridging forms more in the Aleutians or Western Alaska, it would hard to get much -EPO action through the winter. The PDO flipping to negative also hurts the chances of prolonged -EPO.

I'm reserving my final judgment until the first week of November but I see 2 really important themes developing for this winter 1 - I don't think the Pacific is going to be as favorable as some think it will be and 2 - I have real serious doubts about the NAO and AO being negative this winter and no not because of the AMO which seems to be the talk on twitter right now because I have some doubts on how much the AMO has influence on the winter. It is more of a spring and summertime factor from what I have read

[PB GFI]

11 minutes ago, Stebo said:

Agreed, there should be bouts of -EPO this winter but if the ridging forms more in the Aleutians or Western Alaska, it would hard to get much -EPO action through the winter. The PDO flipping to negative also hurts the chances of prolonged -EPO.

 

I am more convinced that the AO is negative this year than I am the EPO or NAO  

Altough SST wise I guess I have  committed 

 

I don't see a predominant NEG PNA so in the abscense of a SE RIDGE I think you will squeeze HP more often then not under the higher heights in the higher latitudes and that source region air helps on the EC,  but definitely into the lakes. 

[uncle W]

soi is still not cooperating...It points to a weak nina at best...

https://www.longpaddock.qld.gov.au/seasonalclimateoutlook/southernoscillationindex/30daysoivalues/

[snowman19]

3 hours ago, PB GFI said:

 

I am more convinced that the AO is negative this year than I am the EPO or NAO  

Altough SST wise I guess I have  committed 

 

I don't see a predominant NEG PNA so in the abscense of a SE RIDGE I think you will squeeze HP more often then not under the higher heights in the higher latitudes and that source region air helps on the EC,  but definitely into the lakes. 

Good discussion. I doubt much +PNA this winter and think it's an RNA winter because of course the Nina and the atmospheric response to that in the convective forcing which we are seeing reflected with the OLR right now but also the absence of the crazy +PDO and super warm west coast waters this year. Giving it another couple weeks to see if it changes but again a huge flip is doubtful at this point 

[Tim198]

Here is the latest 500MB height forecast for the winter from the POAMA model. It does appear to have a negative NAO for December but overall looks quite warm for most of the CONUS.

[Tim198]

Here is the POAMA snowfall forecast. It shows well below normal snowfall for the east.

[snowman19]

14 hours ago, PB GFI said:

 

Ben Noll had a couple of good tweets I'd like to share. This is the atmospheric response and coupling we are seeing in OLR to the CP Nina which is what I was talking about last night. This along with the PDO is why I doubt a +PNA winter: 

[PB GFI]

1 hour ago, snowman19 said:

Ben Noll had a couple of good tweets I'd like to share. This is the atmospheric response and coupling we are seeing in OLR to the CP Nina which is what I was talking about last night. This along with the PDO is why I doubt a +PNA winter: 

2010 Featured a -AO , but this was it`s OCT SSTs .  Totally flipped from where we are now in the EP region . 

The winters of 64/65 , 75/76 , 83/84 , 98/99 , 99/2000 all featured  + AO +EPO s , so there is where this could end up a little different than Ben`s analogs . 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/monthly.ao.index.b50.current.ascii.table

http://www.wxmidwest.com/epo/newepo.txt

Compliments of Chris . 

 

I believe the AO will be a dominant player this year . A weakening NINO and possibly weakening  W QBO in the upper levels along with the current SSTs could promote a neut to - EPO which could allow for some ridging on the WC . 

The JAMSTEC ( with its much AN 2M on the WC )  hints at that , as does NOAA with its AN in the SW . It is too early to be sure and I think we will get a better handle by Thanksgiving .

 

 

[snowman19]

1 hour ago, PB GFI said:

2010 Featured a -AO , but this was it`s OCT SSTs .  Totally flipped from where we are now in the EP region . 

The winters of 64/65 , 75/76 , 83/84 , 98/99 , 99/2000 all featured  + AO +EPO s , so there is where this could end up a little different than Ben`s analogs . 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/monthly.ao.index.b50.current.ascii.table

http://www.wxmidwest.com/epo/newepo.txt

Compliments of Chris . 

 

I believe the AO will be a dominant player this year . A weakening NINO and possibly weakening  W QBO in the upper levels along with the current SSTs could promote a neut to - EPO which could allow for some ridging on the WC . 

The JAMSTEC ( with its much AN 2M on the WC )  hints at that , as does NOAA with its AN in the SW . It is too early to be sure and I think we will get a better handle by Thanksgiving .

 

 

Good points. The thing with 2010-2011 was that early on that winter, November into January it was more of an East Pacific Nina. And that is when we had all that record blocking. During January it started to shift west and by February it became a Central Pacific modoki event. You can see this clearly if you look at the progression of the Nino regions' sstas that winter. February is when all the high latitude blocking disappeared and it never came back again. By the tail end of January the pattern had fallen apart and February through March morphed into a completely different pattern

[PB GFI]

Just now, snowman19 said:

Good points. The thing with 2010-2011 was that early on that winter, November into January it was more of an East Pacific Nina. And that is when we had all that record blocking. During January it started to shift west and by February it became a central Pacific modoki event. You can see this clearly if you look at the progression of the Nino regions' sstas that winter. February is when all the high latitude blocking disappeared and it never came back again. By the tail end of January the pattern had fallen apart and February through March morphed into a completely different pattern

 

I do think we get off the ground early  in December. 

I do want to wait until Thanksgiving to see how this is setting up .

I am on record as saying I believe the AO is neg so I can't walk that back. 

I have not touched the NAO at all because I just don't know and I am just a fan of the warm water in the EP being somewhat of a factor. 

 

We will see. 

[SnowGoose69]

It seems to me too many of the forecasts out there so far, including NOAA's are going too heavy with a Nina look.  This is really a piss poor excuse for a La Nina right now.  Going hard core with the whole Plains cold and snowy and SE ridge seems like a dangerous proposition.  In addition, we are coming off an insanely strong El Nino and there is often some sort of lag in the behavior of the atmosphere.  That lag has been pronounced before in stronger Ninas following big Ninos and stronger Ninos following Ninas, so I'd be really wary of it showing up here.

[SnowGoose69]

18 hours ago, snowman19 said:

I have some doubts on how much the AMO has influence on the winter. It is more of a spring and summertime factor from what I have read

Ehhhh, look at the 70s and 80s and thats all you need to know.  Much colder overall in the East than the 90s and 2000s and less snowy, thats a classic example of the cold AMO at work if you ask me.  Also look how snowy the southern US was in the 70s and 80s, and also in the prior cold AMO period.  Most places in that belt from about 32N to 36N see the majority of their winter snows in cold AMO periods.

[Tim198]

1 hour ago, SnowGoose69 said:

It seems to me too many of the forecasts out there so far, including NOAA's are going too heavy with a Nina look.  This is really a piss poor excuse for a La Nina right now.  Going hard core with the whole Plains cold and snowy and SE ridge seems like a dangerous proposition.  In addition, we are coming off an insanely strong El Nino and there is often some sort of lag in the behavior of the atmosphere.  That lag has been pronounced before in stronger Ninas following big Ninos and stronger Ninos following Ninas, so I'd be really wary of it showing up here.

If you look at things strictly from the SST perspective then yes, it is a piss poor excuse for a Nina. But if you look at tropical forcing it tells a different story. I took a look at the Autumn OLR anomalies for all negative neutral and weak nina years since 1979 (peak ONI of less than -1.0). The years I included were 1980, 1981, 1983, 1985, 1989, 1996, 2000, 2001, 2005, 2008, 2011, 2012 and 2013. I found the forcing to be in a more nina like state (suppression near the dateline and enhanced forcing in western pacific and indian ocean) this year then in any of those other years. The closest match out of all of those years is probably 1996 but I actually found the much stronger nina year of 1998 to be a better match then any of the weaker years.

 

[Tim198]

I've heard a lot of talk about the year 2013 as a possible analog for this year but the tropical forcing is behaving quite differently so far. This year has far more supression near the dateline then 2013 did. There was also more forcing in the western Indian Ocean and less in the east that year. 2013 also didn't have the strong westerly zonal wind anomaly in the Indian Ocean. It was actually slightly negative (easterly) that year. There was also no strong negative IOD like we saw this year. The IOD was neutral to slightly positive that year.

[Tim198]

14 hours ago, bluewave said:

I guess since the PDO is still positive and the La Nina is weak we aren't getting the typical October La Nina NP 500 mb response.

The strong Alaskan ridge so far this month is not characteristic of the October 500 mb La Nina composite.

 

OCT 2016 so far

 

October 500 MB La Nina composite

 

The PDO has actually been negative since August. https://www.ncdc.noaa.gov/teleconnections/pdo/

What's interesting is that while an Alaskan ridge is not common in nina's there is one other notable year that had it...1998. The PAC pattern as a whole is not too terribly dissimilar to that year. (The Atlantic is a different story, however).

 

[Tim198]

11 minutes ago, bluewave said:

The PDO is still positive on the official JISAO site through September. 

http://research.jisao.washington.edu/pdo/PDO.latest.txt

2016** 1.53 1.75 2.40 2.62 2.35 2.03 1.25 0.52 0.45

 

That strong of a ridge over Alaska in October is part of a +PDO signature. The only time that it has been present in October during a La Nina

in the past was the +PDO October La Nina in 1984.  In fact, the only other two Octobers with a strong Alaskan ridge with a trough underneath

near the PAC NW were the El Nino Octobers of 1957 and 1969. 

 

 

 

I personally don't consider any data that's not from NOAA to be official. That website must use a different method for calculating the PDO than NOAA. The NOAA SST maps have clearly shown a negative PDO for the past few months and it's official index supports that.

 

I just posted the 500mb height anomalies for October 1998 and that year also had an Alaskan ridge and NW trough. That year was a moderate/borderline strong nina. I suspect this pattern might be caused by the lingering effects of the strong Nino we had that year and also this year, as well as tropical forcing.

 

The PDO for September of this year (-1.06) was much closer to 1998 (-1.54) than 1984 (0.14) in the official NOAA dataset.

 

11 minutes ago, bluewave said:

 

 

 

 

 

[Tim198]

24 minutes ago, bluewave said:

The atmosphere is still responding like the PDO is positive with all that warm water south of Alaska

and ESE of Hawaii and the JIASO data set reflects that. 

http://research.jisao.washington.edu/pdo/

Yes, I do realize that there's a lot of warm water SE of Hawaii and that's definitely not typical of a negative PDO. But, you also need to look at what's going on in the north PAC. When you look at this past September, for example, you can the warmest SSTs are closer to 150W rather than hugging the west coast. There's actually a weak cool tongue along the west coast. That indicates a negative PDO. A great example of a positive PDO regime would be September 1995 (which registered at 1.02 on the NOAA dataset). You can see the warmest water is hugging the west coast with colder SST further west.

 

[snowman19]

1 hour ago, Tim198 said:

Yes, I do realize that there's a lot of warm water SE of Hawaii and that's definitely not typical of a negative PDO. But, you also need to look at what's going on in the north PAC. When you look at this past September, for example, you can the warmest SSTs are closer to 150W rather than hugging the west coast. There's actually a weak cool tongue along the west coast. That indicates a negative PDO. A great example of a positive PDO regime would be September 1995 (which registered at 1.02 on the NOAA dataset). You can see the warmest water is hugging the west coast with colder SST further west.

 

Good post. Even if you use the other data set the PDO has been on a steady drop for months now. And the last number for JISAO was basically neutral. As you pointed out, the cooling of the west coast ssts is a significant change to -PDO

[uncle W]

this mornings soi was slightly negative again...weak nina likely...December 1995's soi was mostly negative while there was a weak la nina in progress...JB sometimes correlates the -soi with a trof in the east later on...

[Stebo]

3 hours ago, Tim198 said:

Yes, I do realize that there's a lot of warm water SE of Hawaii and that's definitely not typical of a negative PDO. But, you also need to look at what's going on in the north PAC. When you look at this past September, for example, you can the warmest SSTs are closer to 150W rather than hugging the west coast. There's actually a weak cool tongue along the west coast. That indicates a negative PDO. A great example of a positive PDO regime would be September 1995 (which registered at 1.02 on the NOAA dataset). You can see the warmest water is hugging the west coast with colder SST further west.

 

With everything still being warm from the El Nino, it is skewing the data set on that one site to go positive. However when you look at NOAA's data and the maps themselves, this is clearly a -PDO regime we are in even with the ambient warm areas still left. I think that is also skewing people when they are looking at the ENSO regions. They see the positive  near zero regime north and south of the ENSO regions and think that this isn't a La Nina or a very weak one, when the forcing would dictate it is a bit stronger. The residuals left over from the El Nino are muddying the waters but this is clearly a La Nina and -PDO.

[SnowGoose69]

It may technically be a -PDO but that appears to be too minor of a negative PDO for it to have any impact on the UA pattern there.  I would think you would be more likely to end up with GOA or BC ridging in that setup due to all that warm water just to the west despite a weak -PDO 

[Stebo]

38 minutes ago, SnowGoose69 said:

It may technically be a -PDO but that appears to be too minor of a negative PDO for it to have any impact on the UA pattern there.  I would think you would be more likely to end up with GOA or BC ridging in that setup due to all that warm water just to the west despite a weak -PDO 

The thing to watch though is the warm area has been shifting west since the summer and continues to do so. That could change going forward but I don't see anything that would change that at this point. Everything I am seeing points to a strengthening -PDO.

[snowman19]

30 minutes ago, Stebo said:

The thing to watch though is the warm area has been shifting west since the summer and continues to do so. That could change going forward but I don't see anything that would change that at this point. Everything I am seeing points to a strengthening -PDO.

People who don't know see that warm pool and incorrectly assume +PDO when in fact it is a -PDO. I also expect continued -PDO strengthening through the rest of fall and winter

[PB GFI]

On 10/20/2016 at 4:23 PM, snowman19 said:

Are you also seeing a poleward Aleutian ridge dominating with the Niña, westerly QBO in place? Was thinking about it today and I agree with you on the EPO.  I also think this will be a -PDO winter

 

Good DAleo video . He sees that Westerly QBO at 45mb combined with Weak NINA analog with cold throughout  Canada ,  GL and the  NE.