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Is next winter looking like a disaster?


Ji
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Just now, C.A.P.E. said:

A moderate Nino is the sweet spot for the MA in general I believe. More specifically, a Modoki. 2009-10 being the obvious example. Weak Ninos can be utter fails here, and much better for NE.

What I am normally looking for each year is a warm neutral to a moderate Nino. Generally speaking a strong Nino is normally the kiss of death as well as a Nina though we can sometimes score with a weak one. But yeah, give me a moderate Nino with a Modoki any day of the week. Oh and a -NAO if they still exist. :lol: 

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Just now, showmethesnow said:

What I am normally looking for each year is a warm neutral to a moderate Nino. Generally speaking a strong Nino is normally the kiss of death as well as a Nina though we can sometimes score with a weak one. But yeah, give me a moderate Nino with a Modoki any day of the week. Oh and a -NAO if they still exist. :lol: 

Oh a -NAO still exists.. its only extinct in the winter months.:P

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1 hour ago, showmethesnow said:

Pretty much wall to wall winter (Nov-March). Jan-March has a particularly cold look (EPO-cross polar flow) though I don't think the anomalies give the look justice. Some form of a -NAO every month. Looks to be a weakened PV (-AO?). If that were to verify for the winter I don't think there would be any complaining on these boards. Well except for the usual suspects (JI, you out there?) :) 

If the CanSIPS is on to something(real), we won't have to wait too long to see if it really has a clue. Check out October. The "scary" thing is, the CFS has the same idea.

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3 hours ago, showmethesnow said:

What I am normally looking for each year is a warm neutral to a moderate Nino. Generally speaking a strong Nino is normally the kiss of death as well as a Nina though we can sometimes score with a weak one. But yeah, give me a moderate Nino with a Modoki any day of the week. Oh and a -NAO if they still exist. :lol: 

The next -NOA is just 7 months away.

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14 minutes ago, Eskimo Joe said:

Nino and blocking are key here, especially south of I-66.

Many remember the Modaki and moderate Nino during the great winter of  09-10,  but some forget the blocking we had as well.  No wonder great winters are only so often.  But yes,  as CAPE pointed out,  the gold standard of Ninos would be the moderate Modaki type.  

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1 hour ago, frd said:

Many remember the Modaki and moderate Nino during the great winter of  09-10,  but some forget the blocking we had as well.  No wonder great winters are only so often.  But yes,  as CAPE pointed out,  the gold standard of Ninos would be the moderate Modaki type.  

Outside of ENSO state, the AO has the most impact on the character of winter for our region. Without a -AO we need something like the EPO/WPO to be favorable to provide the mechanism for cold air delivery, as we had a few winters ago when the AO was predominantly positive. We generally aren't going to get a -NAO when the AO is solidly positive; having a consolidated, strong vortex parked in the middle atmosphere of the polar region is not very conducive to the formation of sustained anomalously high 500 mb heights in the NA.

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Study on the NAO ...... since you mentioned the NAO and this coming winter 

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019GL084402

Research Letter 
 
Open Access
 

Seasonal Predictability of the Winter North Atlantic Oscillation From a Jet Stream Perspective

 
First published: 19 August 2019

 

In contrast, the slow, decadal variations in both latitude and speed are not captured, despite the pronounced multidecadal variability in jet speed in the reanalysis. This suggests that different processes are responsible for NAO variability on the decadal timescales, and hence that there may remain untapped sources of NAO skill, particularly on the longer timescale. The flip side of this, however, is that forecasting skill on the seasonal timescale in a model may not automatically translate to skill on longer timescales.

The models in general have a reasonable simulation of the Atlantic jet and its variability in latitude and speed, albeit with some discrepancies in individual cases. However, there is not a clear link between a model's simulation of the jet mean state characteristics and its skill in a prediction sense. For example, the ECMWF SEAS5 model was found to have the best representation of the jet latitude and speed distributions, but yet was not found to have significant skill in predicting either of these quantities or the NAO. This suggests that the major problem in this case lies not in the internal jet stream dynamics but in the pathways by which predictable drivers affect the jet stream.

It is interesting that, despite higher skill in predicting the NAO than other systems, the U.K. Met Office seasonal prediction system, GloSea5, appears to misrepresent the close link between the NAO and the jet indices. This could be important, since the jet latitude dominates the observed NAO, and has also been identified here as the clearest source of NAO skill. This discrepancy could contribute to the signal‐to‐noise issue in GloSea5, as predictable signals in jet latitude may not translate to as large a signal in terms of NAO index in the model as in observations.

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13 hours ago, Maestrobjwa said:

Didn't we have a weak PV last winter? Sure, it gave us decent cold, but...didn't do us any good snow-wise!

Not really. At least not substantially so for the majority of winter. The AO was neutral/slightly positive in Dec, then somewhat negative in Jan ( the super awesome SSWE!), then went positive for Feb and March. IIRC.

Statistically, a -AO(associated with a weaker PV) is the number one index that correlates to winter cold and above average snow for the DC area. Always remember that. Close behind(ideally in conjunction with) is an el Nino. Ofc in the absence of a -AO, a -EPO can bring the cold. We have seen that in a few winters this decade. The NAO was predominantly positive during those winters though, so amped storms didn't take a favorable track(mostly rainers).

A legit -NAO typically occurs when we have a sustained/significantly -AO, but not always. -AO/-NAO/moderate Nino is the holy grail for the MA.

 

eta- Here are the QBO 30mb values for October 2018 through March 2019: 

-2.79   3.36   8.05   9.02  9.25  11.82

negative trending positive is typically associated with a strengthening PV

And here are the AO numbers- Notice the only negative value during the winter months was Jan and it was not strongly negative. Despite perception(the SSW/PV split hype), the PV, going by the numbers(and also ground truth) was generally not in a weakened state last winter. AO Correlates pretty well with the QBO index for the same time frame. The negative AO in Jan was indicative of a temporarily weakened PV state that resulted from the SWE.

AO.png.a716b65f50a74cdab53eb059d96d618a.png

 

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1 hour ago, Maestrobjwa said:

Didn't we have a weak PV last winter? Sure, it gave us decent cold, but...didn't do us any good snow-wise!

Well, yes we did but the long awaited blocking in the AO domain never materialized as the models thought it would. ( late Jan through March was when the weeklies and other seasonal guidance forecasted the legit and mouth watering AO and NAO blocking developing )   

Add to that the lack of a Nino background state, and we had little snow and not so much cold. The Pac was more Nina at times. 

The list goes on and on as to why this happened.  

The reason for the Euro's failure was most likely it not seeing the lack of the Nino response as it was more Nina, it never caught on that the atmosphere and ocean was not coupling. 

If you look at the Euro's summer seasonal forecast it did rather well across the US. 

 

 

 

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2 hours ago, BTRWx's Thanks Giving said:

Losing the northeast Pacific blob sucks.

 

2 hours ago, BTRWx's Thanks Giving said:

No, actually what we are seeing is most likely a good thing. 

Below we have current SST's in the PAC. Notice the cold pool in the central/western Pac. This cold pool is surrounded by a horseshoe of warm water around Alaska, down the coast to Mexico and into the central PAC. This is actually getting close to an optimal look for the east coast. We will probably see this cold pool expand in the coming weeks. Though we might see some expansion towards the east my money is on us seeing that expand west to off the coast of Japan. This is a good look for us. Now I circled the ENSO region. Notice we are pretty much looking at a neutral state at this point, possibly moving towards a Nina. I will explain shortly why I am bringing that up.

 

PACSST.gif.486c513f65886c62d774bc9713714755.gif

 

Now below I have the different PDO states. The positive which is similar to what we are seeing with the current SSTs and the negative which is the polar opposite. The positive is the one we are searching for as we tend to see the heights set up in a favorable location to see dumps of cold into the central US and move eastward (-EPO/+PNA). This results in a cold east. The negative on the other hand tends to raise heights farther west off the coast and send the cold shots into the west, move them into the central US and then withdraw them before they get into the east. So what we see is a warm SE and normal temps in the NE.

 

279974109_PDOstates.gif.ffa3d502506037f2404a64db2c8ff7d6.gif

 

Below is a much clearer representation of a +PDO. Notice that we have a much more expansive cold pool and that it is riding up into Japan an eastern Asia. We also have the horse shoe of warm anomalies surrounding it. This is the look we are probably shooting for.

 

PLUSPDO.gif.014686902b43b2269f7593d18f19d110.gif

 

Now as you have seen I have circled the ENSO region on all the maps. Notice what is missing on the current SST map compared to the textbook horseshoe +PDO? A Nino, as we are currently seeing a neutral. So what does that tell us? That we are probably still seeing Nino forcings in the Pacific as we head through fall into winter. We continue to see that cold pool, hopefully expanding somewhat and we are good to go knowing that the PAC will probably cooperate. On the other hand, we see that diminish/disappear and we know that we are losing the Nino forcings and will have to depend on other areas (NAO, AO, etc...) to compensate.

Ninoforcings.thumb.gif.aeb2508bc6a7f5520c19193c9f1767ba.gif

 

 

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