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ORH_wxman

Winter 2020-2021

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I've often thought that altho that early Dec snow last year was within the Met designation of winter that doesn't mean much ... It still to me appeared to really be a part of an autumnal hemispheric setting ...and fitting in with the recent decadal propensity to fold the heights over western Canada ... which tends(ing) to deliver early cold snaps ..etc...  A factor that may also be hidden because it is couched in modestly > normal monthly means ..Or not.  Octobers and Novembers may actually have been closer to normal or approaching so ...while hosting nested cold incursions that plumb departures some -6 to -12,  ....enough so to even snow or be supportive of snow, but rolling out in comparatively briefer time spans - such that by arithmetic weighting, the +3, 10 days intervening "hides" them in the averages..etc..

I feel pretty strongly about that early Dec event as being part of that.  I was in careful observance of the southern tier height compression around the time and moving past ( the weeks) of that event; the hypsometric gradient grew steeper over the ambience, as well .. the isohypsotic counts rose by 3 to 6 gradient lines by mid month, and never 'decompressed' until July frankly... kidding a little.  Within 10 days or so after that early month slow roller quasi-cut-off last December, that spit out a coastal wave for 9-12", then came through with a mid level snowball to double-dutch us for a total 30 hour stint ...  things changed.  Commercial air traffic began reporting the unusual ground-based velocities along .. concurrent with the arrival of that apparent gradient compression. And whether it can be proven geo-physically connected or not, it's hard to ignore that the winter sucked as those observations came about.  It went on to be a distracted mess of busted ravioli systems and sheared out messes...Or at best, modeling bombs that were always correcting 1000(s) of KM(s) east of original projections when at D7-10 leads ( when/where ensemble signals first began to emerge;  the Euro always had Del Marva genesis' ending up flatter or up near NF by D3...etc.. something like that..).  

I think it is important, but the the thematic arc of winters the past 10 years ( and really ... vestiges of this going back to 2000 ) seems to be more than ephemeral ... showing enough sample size to move the climate in insidious ways.  For example, we think of climate in terms of average temperature, #'s of sunny vs cloudy days, precipitation ...wind. Aspect the really are more 'sensible' ...  But, any geophysical variable that is an emergent result of the atmospheric machinery can be metrically analyzed.   Like, 'geopotential gradient' - there probably is normalized/averaged climate values of these lesser known/esoteric aspects, but it is in that obscure realm where climate changes seems to be more colorful.   But, if the 'theme' of winters is changing, and seeing these physical observations to back that .. probably should ignore the possibility that whatever forcing is causing that climate modality, might also do the same for this winters hemisphere.   

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1 minute ago, Typhoon Tip said:

I've often thought that altho that early Dec snow last year was within the Met designation of winter that doesn't mean much ... It still to me appeared to really be a part of an autumnal hemispheric setting ...and fitting in with the recent decadal propensity to fold the heights over western Canada ... which tends(ing) to deliver early cold snaps ..etc...  A factor that may also be hidden because it is couched in modestly > normal monthly means ..Or not.  Octobers and Novembers may actually have been closer to normal or approaching so ...while hosting nested cold incursions that plumb departures some -6 to -12,  ....but by arithmetic weighting, the +3 10 days intervening "hides" them in the averages..etc..

I feel pretty strongly about that early Dec event as being part of that.  I was in careful observance of the southern tier height compression around the time and moving past ( the weeks) of that event; the hypsometric gradient grew steeper over the ambience, as well .. the isohypsotic counts rose by 3 to 6 gradient lines by mid month, and never 'decompressed' until July frankly... kidding a little.  Within 10 days or so after that early month slow roller quasi-cut-off last December, that spit out a coastal wave for 9-12", then came through with a mid level snowball to double-dutch us for a total 30 hour stint ...  things changed.  Commercial air traffic began reporting the unusual ground-based velocities along .. concurrent with the arrival of that apparent gradient compression. And whether it can be proven geo-physically connected or not, it's hard to ignore that the winter sucked as those observations came about.  It went on to be a distracted mess of busted ravioli systems and sheared out messes...Or at best, modeling bombs that were always correcting 1000(s) of KM(s) east of original projections when at D7-10 leads ( when/where ensemble signals first began to emerge;  the Euro always had Del Marva genesis' ending up flatter or up near NF by D3...etc.. something like that..).  

I think it is important, but the the thematic arc of winters the past 10 years ( and really ... vestiges of this going back to 2000 ) seems to be more than ephemeral ... showing enough sample size to move the climate in insidious ways.  For example, we think of climate in terms of average temperature, #'s of sunny vs cloudy days, precipitation ...wind. Aspect the really are more 'sensible' ...  But, any geophysical variable that is an emergent result of the atmospheric machinery can be metrically analyzed.   Like, 'geopotential gradient' - there probably is normalized/averaged climate values of these lesser known/esoteric aspects, but it is in that obscure realm where climate changes seems to be more colorful.   But, if the 'theme' of winters is changing, and seeing these physical observations to back that .. probably should ignore the possibility that whatever forcing is causing that climate modality, might also do the same for this winters hemisphere.   

I never, ever would have guessed....lol

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On 9/9/2020 at 6:30 PM, frd said:

 

As many here already know, the QBO is currently positive and looks to continue to become more so in the months ahead.

There is some research that points out a tendency for a more poleward based and oriented North Pacific Ridge during  +QBO winters. HM mentioned that, along with a couple other mets as well. @griteater recently mentioned it  too in a detailed and revealing post. I found it so interesting as to share it here. Nice job with this ! 

Here is the post below :

The QBO is utilized in various ways with respect to seasonal forecasting, but IMO, it's best use with winter forecasting is not so much with the AO/NAO, but rather, with the configuration of the North Pacific High/Ridge that is common during La Nina winters.  A North Pacific ridge is almost certain to be present in the mean pattern during Cool ENSO / La Nina winters when the Jul-Oct averaged AAM is negative (which has been the case thus far for Jul-early Sep).

 

Anthony Masiello's findings from 2012 showed that more poleward north pacific ridges were favored during +QBO winters, while north pacific ridges that were suppressed to the south were more favored during -QBO winters.  A key element here is that the designation of the QBO for this purpose was in the lower stratosphere (roughly Nov-Feb averaged at 45mb) as opposed to the typical level used with QBO analysis which is at 30mb. 

 

While the QBO began to behave much more erratic than normal at the first part of 2020, it appears to have resumed with a more typical progression as the positive QBO has more firmly established itself in recent months in the middle stratosphere and descending into the lower stratosphere.  For the upcoming winter, I would anticipate the QBO to average positive for Nov-Feb averaged at 45mb - most similar to the winter of 2010-2011 when compared to other cool ENSO winters. 

 

See QBO Charts:

NASA QBO Chart

Free Univ of Berlin QBO Chart

 

Below is a list of what I have for the last 11 La Nina winters that followed El Nino, along with the Nov-Feb avg 45mb QBO, then the placement of the north pacific ridge averaged for Dec-Mar.

 

La Nina Winter That Followed El Nino Winter / Jan-Feb avg QBO at 45mb / Placement of North Pacific Ridge avg for Dec-Mar

2010-2011 / Positive QBO / north/poleward north pacific ridge (specifically, displaced to the NW)

2007-2008 / Negative QBO / south/suppressed north pacific ridge (specifically, displaced to the SW)

2005-2006 / Negative QBO / south/suppressed north pacific ridge (specifically, displaced to the SW)

1998-1999 / Negative QBO / south/suppressed north pacific ridge (specifically, displaced to the SW)

1995-1996 / Positive QBO / north/poleward north pacific ridge (specifically, displaced to the NW)

1988-1989 / Positive QBO / north/poleward north pacific ridge (specifically, displaced to the NE)

1983-1984 / Neutral QBO / no clear distinction overall in the north pacific

1973-1974 / Positive QBO / north/poleward north pacific ridge (specifically, displaced to the NW)

1970-1971 / Negative QBO / north/poleward north pacific ridge (specifically, displaced to the NW)

1964-1965 / Positive QBO / north/poleward north pacific ridge (specifically, displaced to the NW)

1954-1955 / Negative QBO / south/suppressed north pacific ridge (specifically, displaced to the SW)

 

Of the 11 winters, the only one that didn't follow the QBO/North Pacific Ridge placement theory was the winter of 1970-1971.

 

Here are 500mb Height / U.S. Temperature composites of the Positive QBO winters from the list: 

 

543070605_Sep9NinaPosQBO.png.b08d595893ad92d0f7876bd96c35464e.png

 

 

And here are 500mb Height / U.S. Temperature composites of the Negative QBO winters from the list (I left off the 70-71 winter):

 

795617113_Sep9NinaNegQBO.png.8098135465eea56fc7a9085a93bad00f.png

 

Clearly, the Positive QBO composite with the more poleward north pacific ridge offers more potential for cold air intrusion into the lower 48 east of the Rockies compared with the Negative QBO composite.

 

One other thing to look for is the Oct-Nov 500mb pattern over the NE Pacific / Alaska / NW Canada.  Winters with a more poleward north pacific ridge tend to be absent of negative height anomalies in the Bering Sea, Alaska, and NW Canada during Oct-Nov....while, winters with a more southward displaced north pacific ridge tend to contain solid negative height anomalies in the eastern Gulf of Alaska extending up into portions of the Bering Sea, Alaska, and/or NW Canada.

 

Bottom Line: I would expect the upcoming winter to exhibit a more poleward north pacific ridge in the mean pattern as long as: 1) the QBO progression continues in a more typical manner as seen in the past few months, and 2) the Oct-Nov averaged 500mb pattern doesn't contain negative height anomalies in the eastern Gulf of Alaska extending up into portions of the Bering Sea, Alaska, and/or NW Canada  

 

3 minutes ago, 40/70 Benchmark said:

Wow....GREAT stuff.

Food for thought, and it makes sense in that we use the QBO as a predictor for the polar fields, however, I have aways known the +QBO to favor less blocking (+NAO/AO). However, if it were to favor more N PAC blocking during la nina seasons, then that could change things.

Only thing with 2010-2011 is that we also had some NAO assist.

Interesting...

Looks more and more like the path to a very good winter may be though the NPAC....interesting perspective in relation to the QBO shared in the mid atl forum.

I really like griteater's stuff.

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3 hours ago, 40/70 Benchmark said:

 

Looks more and more like the path to a very good winter may be though the NPAC....interesting perspective in relation to the QBO shared in the mid atl forum.

I really like griteater's stuff.

As is often the case 

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I would just like to see less of a black hole across Greenland as that has been killing the east over the last two seasons. If we get North Pac ridging (west of the PNA domain) that's usually when the cold charges into the Plains and the response more often than not, are for lows to move into NY state. Not always the case, but a little confluence to the north would really help. Pacific is always King, but a little help from the Atlantic Queen of Greenland would be nice.

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1 hour ago, CoastalWx said:

I would just like to see less of a black hole across Greenland as that has been killing the east over the last two seasons. If we get North Pac ridging (west of the PNA domain) that's usually when the cold charges into the Plains and the response more often than not, are for lows to move into NY state. Not always the case, but a little confluence to the north would really help. Pacific is always King, but a little help from the Atlantic Queen of Greenland would be nice.

Or just get a black hole so strong and displaced south that we get Dec 2007.....:lol:

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Just now, ORH_wxman said:

Or just get a black hole so strong and displaced south that we get Dec 2007.....:lol:

Oh for sure lol. Although move that north a couple of hundred miles and it would have been like DC. 

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Op ed ( not holier than thou): I disagree the problem with winters has been the NAO domain ... but, to each his own until forcibly proven otherwise in most cases - lol...

Oh, it's not helping - sure.   

There are no one-size-fits-all mechanisms driving weather pattern modes - duh

But, as I have outlined ...to the point of ad nauseam ... there are a larger evidenced systemic morphologies ( I am not averiring some personal opine on the matter! )  taking place in the mass balancing at a hemispheric scope and scale - not sure what the dimensional cost is, but it appears they are order of magnitude ( possibly..) more influential.  These are planetary scope and scale, actually. And [ blah blah blah ad nauseam here ] reasons, it is causing balanced, geostrophic wind saturation and that is disrupting the previous, underpinning pattern mechanisms ( most born between 1900 and 1990 are more accustomed to)  - this is manifesting in numerous ways from Asia and the Indian Ocean to the Americas all the way around the NH winters.   

The NAO ... ?  yeah, it's part of that dizzying array of moving components... but less. 

Nah, the primary loading pattern for cold into N/A is the EPO and always has been.

As a separate concern: The last 20 years has gradually observed a baseline velocity increase ( wind flux mid and upper troposphere), which is stretching/stressing R-wave distribution ... At some point, stretch enough ... the system my "click" into the next 'gearbox cog orientation' ... But, sparing adding that hypothetical popsicle headache to an already mind numbing thumb-swiping missive... the NAO "back drills" as loading pattern,

                                                                                                                          ....as an anomalous scenario from blocking,

which if one spatially imagines... blocking gets harder to do with increased wind fields.. as a gestalt if not discretely provable notion.  yoo hoo ...  We have blocking times, but they are over geographical regions where blocking is more robustly constructed(able) when the surrounding medium is doing so, and the NAO is not one of those. Like, Siberia to the Alaskan sector. 

( Just at an orbital conceptual level, by logical convention and definition of literature combined,  'anomalous' means rarified, and rarified means ... not the primary for the purposes of present context.  )

And that has to be so; conceptually proven objectively and scientifically from empirical data and math ... retrograde behavior is less common than the west to east motion of jets fields and their embedded wave mechanics propagate within the general eddy momentum. It almost seems silly when really, spiritually coming to grips with that truism, how bought into the NAO 'holy grail' the 1990s popularization seemed to become.   The NAO has a contribution in modulating the temperature and to some degree precipitation distribution, which is to say ... > than no effect. Not sure that justifies - assuming this op ed has any truth to it - blaming winters on that factor.   ...obviously, there is a glibness about the 'bus stop' internet social media - there's that too... 

Even Heather Archembault's famous statistical study cited that the PNA had greater statistical confidence interval as a precipitation modulator over eastern N/A... The NAOs were perhaps conditionally correlative... I believe her conclusion offered hypothesis that it was the transition of modes in the NAO.  But, I personally think even that is misleading as a leading cause, because those modality (modal inflection points) are driven by the PNA when time-lags are applied; as R-wave commands downstream, the terminating wave signatures will transitively distribute height nodes into that region ( NAO domain space) ..where/whence there ... underlying geophysical feedback augments ridge structures over that region of eastern Canada's eastern archipelago and Greenlands 5000 feet of elevation and so forth, when the transitive tendency arrives. Because this feedback materializes in situ, that casts a kind of immediate impression that the ridge node up there must have formulated in isolation ...but it may not really be the case.  

The NAO became over-assessing IMHO - old habits and traditions die violently and vitriolically ... 

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A -NAO in the means helps keep the cold further southeast than otherwise would happen. I agree with Tip that you want an NAO that fluctuates a lot in it's magnitude to increase storminess, but you still want in negative in the means...or at least neutral. It provides some level of "cushion" when the EPO/PAC side isn't very favorable.

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But,... my point is, the negative(positive) NAO in the means, may ( and imho likely IS ..) actually transitively forced to be so based on the Pacific as a transitive (time lag) - it's just that those mechanisms are very subtle at times, ...obscuring and masking the root. Find those roots... we don't need the NAO metric -...because it falsely led the event anyway.  The NAO is like looking through the dumpster's content to gather what happened at the party - the problem is...the party's over. Now, if the dumpster keeps filling with the same aftermath ( dumping latent heat into that region where the transitive height tendency is lurking ..., the two will manifest as a blocking mode - but is wrongly attributable as the cause. The lead was the Pac ) then it may have more usefulness in the sense of persistent patterning episodes.

I know...it's a revolutionary thinking and who the f* am I, right? 

Can't say I blame you. I am but a poor boy with drum and a Bachelor's of Science in Meteorology... I am not exactly some kinda postDoctoral rockstar with early consideration for the Nobel Prize for contributions in the area of geophysics ...  understood.    

...There's still plenty of usefulness in looking for ( and ... hoping lol - ) -1 SD NAOs that bounce around... For the rip and read forecasting urgency: The virtue of really knowing why the NAO is neggie(posi-) in the means, may be less important than just knowing the NAO is in that mode/modality.. for shorter to mid range phenomenon.  But a lot of effort and forehead thumb-raking goes on because of the domain's inherent variability overall - models throw up negative(positive) index modes at D6-10 far more whimsically than the EPO for example ( that variability alone sort of suggests its a fragile construct available to butterfly farts) - there is risk in using it.

That said, there would be intrinsic value in predicting the NAO at extended leads... whether 6 days, 10 days, or seasonal notwithstanding... D6 is hard enough... D10? Already it's just a ... f'n fantastically stochastic heartache.

It's that transitive aspect I was discussing ( I personally feel..) - it's like the whip-end of the unmanned fire hose.

But extending this philosophy to even more headachy tortured extremes - if there is any merit/veracity to the "Pac really albeit insidiously hiding its forcing of these NAO variance" model ...it would be useful to physically demonstrate that causal circuitry, because then ...maybe we would have a chance to predict and set the table with that particular metric.  

Think of it this way,  if some aspect of the various Pac mechanics can be closer to highly correlated lag response in the NAO... Than skip the NAO report and just rely on the source.  I grow suspicious over decades of tortured vicissitudes of vagarious winds that the Pac is really controlling the NAO ..

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HM was discussing smoke getting into the lower strat playing a role for this winter. It's a bit different than equitorial volcanism (+AO) given that the smoke is being released into the mid-latitudes and the subtropics. 

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52 minutes ago, Typhoon Tip said:

But,... my point is, the negative(positive) NAO in the means, may ( and imho likely IS ..) actually transitively forced to be so based on the Pacific as a transitive (time lag) - it's just that those mechanisms are very subtle at times, ...obscuring and masking the root. Find those roots... we don't need the NAO metric -...because it falsely led the event anyway.  The NAO is like looking through the dumpster's content to gather what happened at the party - the problem is...the party's over. Now, if the dumpster keeps filling with the same aftermath ( dumping latent heat into that region where the transitive height tendency is lurking ..., the two will manifest as a blocking mode - but is wrongly attributable as the cause. The lead was the Pac ) then it may have more usefulness in the sense of persistent patterning episodes.

I know...it's a revolutionary thinking and who the f* am I, right? 

Can't say I blame you. I am but a poor boy with drum and a Bachelor's of Science in Meteorology... I am not exactly some kinda postDoctoral rockstar with early consideration for the Nobel Prize for contributions in the area of geophysics ...  understood.    

...There's still plenty of usefulness in looking for ( and ... hoping lol - ) -1 SD NAOs that bounce around... For the rip and read forecasting urgency: The virtue of really knowing why the NAO is neggie(posi-) in the means, may be less important than just knowing the NAO is in that mode/modality.. for shorter to mid range phenomenon.  But a lot of effort and forehead thumb-raking goes on because of the domain's inherent variability overall - models throw up negative(positive) index modes at D6-10 far more whimsically than the EPO for example ( that variability alone sort of suggests its a fragile construct available to butterfly farts) - there is risk in using it.

That said, there would be intrinsic value in predicting the NAO at extended leads... whether 6 days, 10 days, or seasonal notwithstanding... D6 is hard enough... D10? Already it's just a ... f'n fantastically stochastic heartache.

It's that transitive aspect I was discussing ( I personally feel..) - it's like the whip-end of the unmanned fire hose.

But extending this philosophy to even more headachy tortured extremes - if there is any merit/veracity to the "Pac really albeit insidiously hiding its forcing of these NAO variance" model ...it would be useful to physically demonstrate that causal circuitry, because then ...maybe we would have a chance to predict and set the table with that particular metric.  

Think of it this way,  if some aspect of the various Pac mechanics can be closer to highly correlated lag response in the NAO... Than skip the NAO report and just rely on the source.  I grow suspicious over decades of tortured vicissitudes of vagarious winds that the Pac is really controlling the NAO ..

It seems you are implying there is a covariance and correlation between the EPO/NAO...or PNA/NAO or both....which is reasonable. They both exist and we've talked about it over the years.

 

But I think the discussion was more centered around when the EPO/PNA aren't doing us a lot of favors....that's when a -NAO in the means can help out a lot. We're talking when they are "out of phase" with eachother. An anecdotal occurrence off the top of my head was early January 2009....we had a nice vortex sitting over AK (very temporary I'll add), but we developed the best NAO block of the season during that time which prevented us from torching away all our snow and dealing with storms tracking through Marquette. Instead, we stayed more on the seasonable side of temps and dealt with a couple transition snow/ice events.

The same assistance occurred to a lesser extent right before the Feb 2013 blizzard.

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2 hours ago, ORH_wxman said:

A -NAO in the means helps keep the cold further southeast than otherwise would happen. I agree with Tip that you want an NAO that fluctuates a lot in it's magnitude to increase storminess, but you still want in negative in the means...or at least neutral. It provides some level of "cushion" when the EPO/PAC side isn't very favorable.

Yea, an NAO that fluctuates between "your porked" and "your f*cked" like last season is no bueno.

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1 hour ago, ORH_wxman said:

It seems you are implying there is a covariance and correlation between the EPO/NAO...or PNA/NAO or both....which is reasonable. They both exist and we've talked about it over the years.

 

But I think the discussion was more centered around when the EPO/PNA aren't doing us a lot of favors....that's when a -NAO in the means can help out a lot. We're talking when they are "out of phase" with eachother. An anecdotal occurrence off the top of my head was early January 2009....we had a nice vortex sitting over AK (very temporary I'll add), but we developed the best NAO block of the season during that time which prevented us from torching away all our snow and dealing with storms tracking through Marquette. Instead, we stayed more on the seasonable side of temps and dealt with a couple transition snow/ice events.

The same assistance occurred to a lesser extent right before the Feb 2013 blizzard.

 

Although I know what covariance means in a mathematical context - ... it seems I am failing to get a specific point across to folks:

I don't believe there really is a scenario where/whence, " ...Aren't doing us a lot of favors...that's when a -NAO" ...   NO, I believe in those scenarios it only appears that former aren't doing the favors...   - it's exactly a scenario where it 'appears' the NAO is operating singularly and alone, disconnected... and I just personally don't believe that is really the case. The Pac/PNA/EPO or somehow loading wave kinematics transitively through the medium of N/A and as it then emerges in ridge(trough) expressions up there D-Str and the like ... viola!  Looks like the NAO was emerging on its own.  

Can't make it any simpler than that... Doesn't have to be right ...but I believe it is... We see wave harmonics ( I'll point out - ) all the time cause nodes of constructive and destructive interference that don't come into phase until further down the line... The atmosphere can behave this way as it is a wave schematic.    kinda fascinating... 

 

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4 minutes ago, Typhoon Tip said:

 

Although I know what covariance means in a mathematical context - ... it seems I am failing to get a specific point across to folks:

I don't believe there really is a scenario where/whence, " ...Aren't doing us a lot of favors...that's when a -NAO" ...   NO, I believe in those scenarios it only appears that former aren't doing the favors...   - it's exactly a scenario where it 'appears' the NAO is operating singularly and alone, disconnected... and I just personally don't believe that is really the case. The Pac/PNA/EPO or somehow loading wave kinematics transitively through the medium of N/A and as it then emerges in ridge(trough) expressions up there D-Str and the like ... viola!  Looks like the NAO was emerging on its own.  

Can't make it any simpler than that... Doesn't have to be right ...but I believe it is... We see wave harmonics ( I'll point out - ) all the time cause nodes of constructive and destructive interference that don't come into phase until further down the line... The atmosphere can behave this way as it is a wave schematic.    kinda fascinating... 

 

So you believe that the PAC modulates the Atl....hard to substantiate or dispute, but logically it makes sense, since the former is much larger and upstream.

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Just give me some self induced transient blocks and a charged negative EPO and let the chips fall where they may. NAO is great for snow retention and cold though.

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8 minutes ago, 40/70 Benchmark said:

With the exception of March 2018, you have to go back to March 2013 to find a DM winter month that averaged a negative NAO in the means.....think about that. 

Food for thought for some of the "All Regression All of the Time" crew....

For all of the crap that we give the 80's, which were paltry in terms of snowfall, only one season from that decade managed to not average at least one neg NAO month in the means......1988-89, which was a strong la nina.

I wonder if Tip's, expanded Hadley cell and attendant uber fast flow is responsible for the rarity of the neg NAO over the past several years...

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6 minutes ago, 40/70 Benchmark said:

So you believe that the PAC modulates the Atl....hard to substantiate or dispute, but logically it makes sense, since the former is much larger and upstream.

I remember reading something about that. It's possible given a certain wavelength pattern and amplitude I think. I don't see why it can't be one of Tip's "constructive interference" type setup.

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8 minutes ago, CoastalWx said:

I remember reading something about that. It's possible given a certain wavelength pattern and amplitude I think. I don't see why it can't be one of Tip's "constructive interference" type setup.

Yea, I have no issues with that theory. I just don't have the background to empirically validate it...

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I mean technically everything is upstream of eachother since we're going around a spherical object....

 

But yeah, Tip is parsing the difference between what an index says and the "responsible party" for that pattern. I wasn't doing that....I'm merely stating that often a -NAO will be paired with a +PNA/-EPO type pattern, but when it isn't, it's really helpful to have. I'm not here to dispute that something in the PAC is causing that -NAO to occur....I'm just pointing out how helpful it is to occur during a shitty PAC pattern. 

I've actually often stated that our best snow patterns are -PNA/-NAO/-EPO....kind of a weird trifecta on first glance, but think of something like Jan 2011 or Feb/Mar 2013. But obviously you can do the big snow thing other ways too....see 2015.

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On 9/18/2020 at 7:29 PM, ORH_wxman said:

NAO went steeply negative in October 2009 and basically stayed that way for 15 months. It doesn’t always swing back. 

Those were the days (really up through 2013) when everyone started thinking that NAO blocking “was the new normal”. Didn’t take long for that idea to bust. 

I know what he means, though....I gotta admit that I hate seeing the NAO really dip in October. More often than not, it does't lock in for several months.

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20 hours ago, OSUmetstud said:

HM was discussing smoke getting into the lower strat playing a role for this winter. It's a bit different than equitorial volcanism (+AO) given that the smoke is being released into the mid-latitudes and the subtropics. 

Anyone care to elaborate on this?

I don't know much about the impact of that, so its a real wild card...

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18 hours ago, ORH_wxman said:

I mean technically everything is upstream of eachother since we're going around a spherical object....

 

But yeah, Tip is parsing the difference between what an index says and the "responsible party" for that pattern. I wasn't doing that....I'm merely stating that often a -NAO will be paired with a +PNA/-EPO type pattern, but when it isn't, it's really helpful to have. I'm not here to dispute that something in the PAC is causing that -NAO to occur....I'm just pointing out how helpful it is to occur during a shitty PAC pattern. 

I've actually often stated that our best snow patterns are -PNA/-NAO/-EPO....kind of a weird trifecta on first glance, but think of something like Jan 2011 or Feb/Mar 2013. But obviously you can do the big snow thing other ways too....see 2015.

Correct!   

and to reiterate: "......There's still plenty of usefulness in looking for ( and ... hoping lol - ) -1 SD NAOs that bounce around... For the rip and read forecasting urgency: The virtue of really knowing why the NAO is neggie(posi-) in the means, may be less important than just knowing the NAO is in that mode/modality....

But I extend the notion that "IF" science or special insight ...or flash of insight or miraculously the woman of one's dreams finally returns ... can all point out the NAO's true force-origin, than deterministic forecasting would greatly benefit from that know-how.   Imagine... ?  Being able to say, " There is a 75% likelihood that the NAO will negative(positive) the third week of October, because of x-y-z in the Pacific transmitting a signal down stream" ??  Furthering yet ... because of wave mechanics, knowing the ridge up there is likely to position west or east based...   

But agreed, whether it is for responsibly intelligent daily operational efforts in forecasting, or increasing the potency of this social media's addiction to weather drama ... for either "virtuous" cause, taking note of the NAO has practical usefulness.  I was not by extension of these philosophies really intending to abase the usefulness of the NAO - though of course ... the implication does bring it down off it's pedestal some. Sure. ( lol ) but no

Hypothesis: I just think that the NAO, being inherently downstream of all events in a west to east momentum oriented planetary eddie, cannot really be primary in 'why' there is a snow storm in D.C. 

It may look that way at a superficial observation, because during or even leading, it is demonstrable on the weather chart, pulling attention to it.. But, the hypothesis presently is that those heights are really emergent from larger/longer scaled wave mechanics; perhaps some sort of lag harmonics from superposition aspects terminating downstream. 

You know, I've read literature about MJO/atmosphere around the Indian Ocean having lag correlation with the NAO, ...I may have seen it on television Science Channel program too.  In both presentations the insight was under the auspices of "we don't know why" -  ... I feel hugely confident to the point of averring an outright awareness, that is an example of a transmitted or transitive wave distribution.

Adding to that... waves terminating at different rates are arriving from several sources, all the time.  All of which constructively or destructively interfering ...  And I caught your suggestion/point that ultimately everything is east of you on a rotating spheroid - but hmm.. Said sphere is not a homogenous surface? It has oceans and mountains .. and these differentially disrupt an otherwise "Neptunian" laminar flow.  But Greenland is fixed, so it's impact on the atmosphere is fixed... and being a plateau that is some-odd .5 to 1 mile high, it presence formidably. I suspect there is a smaller-scaled yet significant analog ... similar to the atmospheric PNAP bulge that exists over western N/A.  Such that as these lag harmonics pass over that geographical region, they get a positive feedback and are thus physically driven to express ridging.  

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2 hours ago, 40/70 Benchmark said:

Anyone care to elaborate on this?

I don't know much about the impact of that, so its a real wild card...

"Sounds" like he was dancing with the Ozone/stratospheric correlation science - that which relates to sudden stratospheric warming.  Smoke is not Ozone - but it does introduce a sub-micron down to molecular-scaled presence in the atmosphere; that may behave similarly.  

But that's the tip of the iceberg for that science. Slow moving at that.  How its presence in the stratosphere relates to the PV ... I wanna say 1980s?  But don't quote that...

The solar cycle's relationship with that former Ozone circuitry: Solar mins deliver less UV part of the EM spectrum. That reduction lengthens the Ozone residency in the atmosphere - the impetus being ...UV wavelengths break down the Ozone molecular structures. UV cleanses the stratospheric Ozone in a sense..  A blank solar disk summers/autumns (which this is a solar Min summer btw -)  preceding those winters, may result in increased Ozone mass ...  That is important because Ozone is thermally conductive - 

So... terminating WAA events from planetary wave dispersal ...both at higher altitudes and latitudes ( that just means warm air arriving ..) infuses/delivers thermal energy into the ambient PV ( polar vortex ), where (then if) there happens to be a conductive efficiency in place, courtesy of a sleeping sun, viola!  There is a warming that "suddenly" takes place... It is often accompanied by an immediately leading and/or concurrent U/Z-vector wind anomaly(s), which are probably the result of the arriving planetary wave mechanics showing up as a redistribution in the PV's structure.. But, if this thermal proficiency is not in place, these arriving warm pulses evaporate/disperse radiatively before the medium gas has a chance to absorb kinetically...

So, if the mid and high warm pulse of air is present - and this is the part I am less clear on ... - it seems to defy conventional buoyancy arguments, and may begin to "downwell" ... This downward movement of the plume of warm air is crucial in the correlation to the AO ... I have spent hours actually cobbling posts festooned with annotations to demo this in the past... But, I bring it up because this downward motion of the warm plume is often misrepresented and or missed in the conceptual publications I see bandied about the enthusiast and even professional community - be it online, on television ..in science fiction noveling... you name it. People see a warm departure and they pull the SSW card and J. B. used to do this ... making me suspicious over whether he actually knew how the model worked... I can show you plenty of warm blobs in the data set that did not move downward - and guess what...there were no subsequent -AO observed above noise... etc..  But virtually all of those that downwelled, did and the AO made 2 to 3 week excursions negative when the plume descending to approximately the 100 to 200 mb sigma levels. 

What it does is ... stabilizes the ambient PV and that weakens the storm of it ( so to speak..) breaking down its circulation ... As that occurs, it radially expands S in latitude...and regions above the periphery than experience more DVM nodes and heights blossom --> blocking ensues...etc...  -AO 

Then there has been many papered research efforts relating the QBO phases with that SSW tendency as well... Since the QBO is a fluid mechanical phenomenon, ...guess it doesn't take a huge intuitive leap to see how all that above might have a relationship if they are concurrently happening in the same planetary system - huh.   There appears to be a west ( more blocking ) versus easterly phase ( less blocking )?  I may have that backwards just off the top of my head... There may be a missing circuit that relates all these together into a seasonal tendency.. 

And also, in fairness ...this what I researched of this/these subject matter(s) as of 8 years ago - surely enough time to have evolved the understanding further.    

But, Ozone vs QBO .. both have veracious statistical correlations.  Usually when covariance kicks in, I start suspecting there is an "invisible" real driver that relates the two - but who knows.

It seems like per my own observation...

-- a  (QBO(E) + Solar Min)  = higher likelihood of SSW

-- a  (QBO(W) + Solar Min) = reduced, but still elevated likelihood of SSW

-- a  (QBO(E)  + Solar Max) = reducing more, but still elevated likelihood of SSW

-- a  (QBO(W) + Solar Max) = lowest chance for observing an SSW     

                                                  by "likelihood,"  means comparing against the longer term frequency - and if I have the E vs W backward, just switch those lol.. 

Lastly, I don't know what HM was really talking about...I'm just saying it smacks as related to much of this.  I also want to point out ...there can be -AO winters that do not have SSW phenomenon observed. There can be +AO winters with a single SSW event and some 2-week period where the AO did fall...but may not have been negative - but the fall characterizes the influence of the former.  The problem is, SSWs are just one component in driving total seasonal polar teleconnector/index behavior... It's like the NAO became - imho - overly assessed and popular in the 1990s and the SSW probably will have to go through that meme popularity curve too -

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