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Winter 2019-20 Preseason Discussion


WxUSAF
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I see even HM graced Judah's post, not something you see everyday :-) 

Wonder whether this roll out is somewhat different from last year in a way,  as it may yield a colder early December , similar to early December last year , but where this year may  differ is that we do not return to a warmer regime like last December when things looked great in late November and early December and then BAAM we lost the good pattern in mid-December.  

Also,  the caveat here for this December again may be what some referred to last year as a bootleg  - NAO, and the interplay of the Scandinavia block.      

 

 

 

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The tricky thing with the Modoki readings is that the overall value can be skewed positive or negative by the "Box C" waters - by the Philippines that don't really impact the Eastern US.

In other words, these are both high (EMI - El Nino Modoki Index) Modoki winters:

Box C        Box A        Box B         (Box A)-(0.5*Box B)-(0.5*Box C)

W Pac      Cent Pac    East Pac   Modoki

+1.0           +2.0              +2.0          (2.0)-(0.5*2)-(1*0.5) = +0.5

+0.2             +1.6             +2.0          (1.6)-(2.0*0.5)-(0.2*0.5) = +0.5

Those are both exactly the same on the Modoki index. The first El Nino I listed is fairly similar to 2015-16. The second is pretty different...but would be scored the same on the EMI. When I say I use El Nino Modoki stuff for my analoging, I use all three boxes. The actual EMI values don't matter to much since you can arrive at the same values in different ways. The only way to get the entire Western US super cold seems to be with Box C cold, and then the other two warm - which is why it basically never happens anymore. Last year was only 1-2F below normal for the SW.

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3 hours ago, frd said:

I see even HM graced Judah's post, not something you see everyday :-) 

Wonder whether this roll out is somewhat different from last year in a way,  as it may yield a colder early December , similar to early December last year , but where this year may  differ is that we do not return to a warmer regime like last December when things looked great in late November and early December and then BAAM we lost the good pattern in mid-December.  

Also,  the caveat here for this December again may be what some referred to last year as a bootleg  - NAO, and the interplay of the Scandinavia block.      

 

 

 

If the polar vortex gets dislodged by the end of October, which some models are hinting at, then the relaxation in December similar to last year is more likely imo.  We are way too early to want a pv!

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11 minutes ago, BTRWx's Thanks Giving said:

If the polar vortex gets dislodged by the end of October, which some models are hinting at, then the relaxation in December similar to last year is more likely imo.  We are way too early to want a pv!

Mercy above...why do the preliminary elements of this winter look like they're trying to play copycat? Smh Well, at least this time we'll know what to expect if this continues...15-18" for the season with scattered nickel and dime events that'll make decent scenery but not enough to pack a punch...(at BWI anyway...lol DC got the better punch from the January storm!) No lofty expectations like last year!

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26 minutes ago, Maestrobjwa said:

Mercy above...why do the preliminary elements of this winter look like they're trying to play copycat? Smh Well, at least this time we'll know what to expect if this continues...15-18" for the season with scattered nickel and dime events that'll make decent scenery but not enough to pack a punch...(at BWI anyway...lol DC got the better punch from the January storm!) No lofty expectations like last year!

Does it ever occur to you that chaos, or a large number of tiny variables that we cannot accurately predict, will have a greater impact on our snowfall that you seem to take into account when you make these very specific “expectations”.  

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6 hours ago, psuhoffman said:

Does it ever occur to you that chaos, or a large number of tiny variables that we cannot accurately predict, will have a greater impact on our snowfall that you seem to take into account when you make these very specific “expectations”.  

lol what a bad couple of posts- the one he replied to is even worse. Yes, because what we want to see heading into early Nov is a strong SPV- a big consolidated blue ball. That means Dec should rock!

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8 hours ago, BTRWx's Thanks Giving said:

If the polar vortex gets dislodged by the end of October, which some models are hinting at, then the relaxation in December similar to last year is more likely imo.  We are way too early to want a pv!

Although there appears to be some similarities I doubt we go down that same path again. As I mentioned a simple elongation towards us or at the least keeping the PV in check is fine with me. 

As you know , many blamed the SSWE last December and what lead up to it as one reason, among many , ( QBO . meager Nino,  weal Pac jet , etc. ) for the poor performance of the seasonal models and many mets as well. 

Personally the one thing I like to see change is for the PNA to go positive, and for ridging to develop closer to the West Coast. It seems the way things are playing out the jet then reacts to this flow with a pumping up of the WAR , so a trough out West and a ridge in the East.  This needs to change in the weeks ahead or at least  transition to a better Pac. 

I know bluewave mentioned the SST configuration in the PAC and  how the warmer waters out there may feedback this. 

Borrowing a image from a crankyweather post you can see those warmer waters. But things are changing again with the SSTS and will see what happens when we get later into the Fall .

The image shows the trough in the East but currently it is more so in the West. I use the image simply to view the warmer water configuration. 

Lastly, when you think about that image below it is more so related to what Paul describes here ( see below ) So when we go more towards a Nino look hopefully the East will benefit. 

    

You get the direction of causality mostly backwards. The high SSTs in that region are a consequence of ridging there, more than the other way around.

 

Image

 

    

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8 hours ago, Maestrobjwa said:

Mercy above...why do the preliminary elements of this winter look like they're trying to play copycat? Smh Well, at least this time we'll know what to expect if this continues...15-18" for the season with scattered nickel and dime events that'll make decent scenery but not enough to pack a punch...(at BWI anyway...lol DC got the better punch from the January storm!) No lofty expectations like last year!

???

I am already already seeing some differences/tendencies in the evolution from last year to this year. We may see 15-18" (not saying we do) when all is said and told but it probably won't be because it copied last year.

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10 hours ago, psuhoffman said:

Does it ever occur to you that chaos, or a large number of tiny variables that we cannot accurately predict, will have a greater impact on our snowfall that you seem to take into account when you make these very specific “expectations”.  

Well...what looks different from this time a year ago? I'm hearing the same language from others: about the Hadley cell, the Nino possibly "not coupling" to the atmosphere again...SST's looking the same as they did this time last year, PDO looking negative if not more so as this time last year (and hearing someone else in that thread else suggest that that look screamed "trough in the west, ridge in the east")...so I thought perhaps saying last year is a safer bet if you were a gambler...lol I mean, is there anything to suggest we'd see more than last year right now? (NAO?) Could always be less, of course...I never rule that out around here, lol

 

And btw, while I'm coming around a bit more to the reality of "chaos" in forecasting...I still don't like it, lol But I am slowly learning that it's better to expect it to break wrong in higher expectations...and ignore it and be pleasantly surprised if it breaks right in lower expectations.

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4 hours ago, C.A.P.E. said:

lol what a bad couple of posts- the one he replied to is even worse. Yes, because what we want to see heading into early Nov is a strong SPV- a big consolidated blue ball. That means Dec should rock!

I'm learning...be patient. I'd rather you, like psu, tell me WHY I'm wrong...that's why I post. Learn more that way. Not flying off the handle here...

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Maybe November is closer to normal in the states. Here in the East looks average to above based on this. Of course things could change. Don S. thinks the East could be warm after the first week of November.  

I was really hoping for a colder month.  Certainly snow cover should build over Canada,  possibly at an above climo rate, and wondering if we get some extreme cold air mass to develop also in time later in the month up North.

Looks like continuation of the same old thing to a degree. 

 

 

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36 minutes ago, Maestrobjwa said:

I'm learning...be patient. I'd rather you, like psu, tell me WHY I'm wrong...that's why I post. Learn more that way. Not flying off the handle here...

We want to see the SPV consistently and systematically disrupted and perturbed. Perpetually pummeled. That translates to the negative phase of the AO, and that process starts in the fall. During the winter months, a sustained –AO correlates strongly to cold and above average snowfall for the MA region.

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31 minutes ago, Maestrobjwa said:

I'm learning...be patient. I'd rather you, like psu, tell me WHY I'm wrong...that's why I post. Learn more that way. Not flying off the handle here...

No two seasons are 100% alike.  Even the most similar of seasons wrt telleconnections aren't complete clones.  There are always subtle differences here and there.  And then there are the multitude of smaller variables that we really cannot accurately measure and factor into the equation on a seasonal scale either because they are too delicate or because we have no ability to predict them at long leads.  That is why in every analog set there is some variance to the results and sometimes an extreme outlier.  It's easier in hindsight to "throw them out" or analyze why that year was an outlier, but going into that season no one expected that result.  Look at 1995 and 1996.  Back to back years, with totally opposite results, and each is in the opposite analog data set from the results you would expect.  

I wasn't even saying you are "wrong" per say, just that it seems from my observations of your posts that you have a tendency to latch onto things in an attempt to prescribe a level of predictability that simply doesn't exist in long range and seasonal forecasting.  Even some of the best seasonal forecasters only hit about 60% of the time. The problem isn't so much what your expectations are, its that you have expectations at all when it comes to long range snowfall.   

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Some folks are talking about why the seasonal models are going with a mostly positive NAO and a + AO in the winter forecasts. 

Simon believes it is due to the models seeing a stronger winter PV.

IMHO I don't see that. Sure,  it may, as others stated, get stronger in November, but off the charts strong well I am not so sure. 

Also, the pattern supports some attempts at weakening the PV and don''t forget the descending QBO as well.  Maybe @Isotherm could comment. 

I read from one source that the signal for the + NAO and + AO also may be related as to how the seasonal models see and resolve oceanic SST profiles. 

However, a great video from BAMMwx recently mentioned that most model SST forecasts out in time are not correct. I forget the exact wording but he stated they are only correct 19 % of the time. 

He also mentioned that the model, NMME or close to that,  is notorious for being too warm. So since the oceans play such a huge role in driving the pattern if those seasonal models are off in forecasting future SST profiles, then the seasonal temp forecasts will be off along with other outcomes. 

 

This is also a great addition to this topic, from Zac. 

 

 

 

 

 

  

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1 hour ago, 40/70 Benchmark said:

 

So maybe the CanSIPS has been on to something for several months now? Asking for  a friend. I would love a wall to wall winter with HL blocking, but cant get past the persistence aspect of a predominantly +AO/+NAO regime during the winter months for what seems like an eternity now.

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So maybe the CanSIPS has been on to something for several months now? Asking for  a friend. I would love a wall to wall winter with HL blocking, but cant get past the persistence aspect of a predominantly +AO/+NAO regime during the winter months for what seems like an eternity now.

I saw a note on Tropical tidbits about an update to the CanSIPS. I’m not sure how long that notice had been up on the site so I decided to check it out and see if it had changed. Dec, Jan and especially Feb are stout +AO/NAO on the 0z sep 30th run.
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26 minutes ago, poolz1 said:


I saw a note on Tropical tidbits about an update to the CanSIPS. I’m not sure how long that notice had been up on the site so I decided to check it out and see if it had changed. Dec, Jan and especially Feb are stout +AO/NAO on the 0z sep 30th run.

Yeah it has been advertising that look since July I believe. Been steadfast with a bigtime HL blocking look. I guess the true test is to see if it begins to develop in early to mid Nov, as it has been indicating that to be the case for several runs now. We won't have to wait too long to see if it is onto something, or way out in left field.

eta- just looked and it is much different now, so something has changed lol. The original Oct 1 run had a bigtime -AO/-NAO like the previous runs- now it looks more like the CFS. Oh well. More in line with the rest of the seasonal/climate models.

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Yeah it has been advertising that look since July I believe. Been steadfast with a bigtime HL blocking look. I guess the true test is to see if it begins to develop in early to mid Nov, as it has been indicating that to be the case for several runs now. We won't have to wait too long to see if it is onto something, or way out in left field.




Not that it matters a ton but something was updated...

212f7378d3cec35afbc6e1290b4fefac.jpg

5a7891adad3a35e360ec19412b63b00f.jpg
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3 minutes ago, WxUSAF said:

I think you’re both talking past each other. Most recent run did a big flip to +AO/NAO. Older runs were major -AO/NAO. 

Yeah I just looked. The original Oct1 run  had a -AO/NAO. I Posted about it when it came out..So there has been some sort of an update. Pretty crapola now.

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