Re: Long Range Thread 27.0

[rb924119]

Trust the process, folks, and get your sleep. As I’ve said before, the models are going to struggle seeing what I think should happen until it’s much closer in time. There are A LOT of factors working in our favor to give us a memorable winter, and their constructive interference is going to start being realized. The idea of transitioning after the 20th has evolved as expected, now as we enter the new year, it’s time for the hammer to drop.

[aiannone]

Trust the process, folks, and get your sleep. As I’ve said before, the models are going to struggle seeing what I think should happen until it’s much closer in time. There are A LOT of factors working in our favor to give us a memorable winter, and their constructive interference is going to start being realized. The idea of transitioning after the 20th has evolved as expected, now as we enter the new year, it’s time for the hammer to drop.

From your mouth to Mother Nature’s ears!!

[chief7]

Bring it home Rob

[rb924119]

The reversal of the Stratospheric winds is irrelevant, Scot; it’s a byproduct of the warming. The warming is what effects the actual changes in the atmosphere, not the wind reversal.And with the warming where it is, you’re going to have a “shadow” vortex develop equatorward of it, relative to averages

That’s my exact point Ray. Esp when there is no reversal the position of the SPV is critical. Up through now it’s position has been poorly oriented for most of NA.

Ignore the reversal, it’s irrelevant to the sensible weather. The only thing it satisfies is tue textbook definition. The evolution of the warming is what matters. The warming in the Stratosphere that you currently see on maps has been ongoing since the first week of December. Those fluxes are going to start impacting the Troposphere next week. So to say that the state of the Stra today is effecting the weather today isn’t fair. You’d have to look at November to see how the Strat  evolved in order to make the argument you’re making. That’s my point.

I couldnt disagree more.  I think at times, major changes to the strat can take time to see the result of the surface yes.  But I also think while it may not be directly influencing the trop they are always linked.  Under certain conditions more so, and others less so.   Despite a term we want to call a tropopause, there is no definite large scale piece of cellophane separating the two.  So under relatively stable conditions, or minor changes to the strat you can see direct correlation between where the lowest heights of the SPV live and the TPV live.  This can be demonstrated over and over.  A change at the strat isnt locked to a 3-6 week lag time when they have been coupled as they have been between 10mb down through 100, and consequently the troposphere.  But as the forecast shows the 10mb nd 50mb SPV is set to de couple as a result of a second even stronger wave of warming begining at the top10m and eventually translating down.  

I think the warming throughout Dec was such that it weakened the SPV some but actyed more to push it, rather than to strongly weaken it.  There wasnt enough weakening and warming of the vortex itself, just the surrounding ridging acted as an expanding balloon that pushed the vortex over to the wrong side of the hemi.  And because there is some link and has been since the fall the 500mb pattern responded accordingly.  

.....back to our regularly scheduled programming. Sorry, folks, I didn't mean to hijack this thread, but again, I felt that my other post was appropriate given the amount of passion in this debate.

Im going to take my response to this piece by piece, Scott.

1. I think at times, major changes to the strat can take time to see the result of the surface yes.  But I also think while it may not be directly influencing the trop they are always linked.

To start off, it's widely agreed upon by those who have studied Troposphere-Stratosphere fluxes that the average lag period is approximately one month. I have read this in several papers over the years, though, obviously, the exact amount of lag is dependent upon various factors, most notably the strength and duration of anomalous flux. I have subjectively adapted my own lag time when it comes to forecasting based on a combination of experience, research, and analysis of conditions leading up to each particular event. That's how I come up with my (subjective) time frame of a general 3-6 weeks. For example, this event is taking approximately one month to be expressed. However, I think the follow-up event (happening now) will not take nearly that long as the atmospheric "receptivity" to these fluxes is much higher. Conceptually, think of this first event as the "primer", while the next event (evolving as we speak.....or, type lol) will already have the foundation laid for it to be more quickly reflected in the Troposphere. That's how I look at it. So, conceptually, the follow-up event should end by the first week of January, and I think by Week 3, the results should be evolving in the Troposphere. We will see how this works out.

To your second point, I don't fundamentally disagree with you, but again, I think that you are taking the linkage too directly, and are not properly accounting for the observed and well-demonstrated lag between the two atmospheric levels. And that lag goes both ways. For example, sometimes blocking in the Troposphere can be what causes the Stratospheric vortex disruption, and, in certain orientations (one of which we will be seeing evolve beginning later next week) the flux transport is more efficient than in others (sustained ridging in the NAO and EPO/WPO domains are the most efficient mechanisms for inducing vertical fluxes to the Stratospheric vortex). So, keep this in mind, as this will work in our favor to continue to perturb the Stratospheric vortex, and we should see a THRID warming event as we get toward the end of January and beginning of February, especially with the presence of the easterly QBO, but this one will be induced by the strong blocking in the NAO domain.

2. Despite a term we want to call a tropopause, there is no definite large scale piece of cellophane separating the two.

To this point, ok, no; there isn't a truly impermeable layer separating the two. But don't forget, the Tropopause is a large inversion that separates the Troposphere from the Stratosphere, so, there actually IS a separation between the two. Let me show you something:



Here's a conceptual model of our Troposphere ("T"), Tropopause ("T.P."), and Stratosphere ("S") based on a thermal profile. The black "C" (cold) and "W" (warm) represent the temperature scale, and the red line denotes the general thermal profile throughout the three vertical atmospheric layers. As you can see, the Troposphere cools with height, the Tropopause starts generally isothermal (steady temperature) then warms with height before leveling off again, and then the Stratosphere cools with height again. I think we can both agree that, in the Northern Hemisphere, the wind always blows with cold air on the left, correct? That's why we have westerly jets. In the middle of the Troposphere AND the Stratosphere, this would result in wind going INTO the page (or, in our case, the computer/phone/tablet screen).

Now, take a look at the green circles on the thermal diagram, labeled "1" and "2", and go to the top of the graphic where I zoomed in a little bit. Also notice how I have "C" (cold) and "W" (warm) color coded now. Ok, so in the first circle, you can see that we clearly have colder air sitting beneath warmer air. As a result, we would conceptualize a wind coming OUT of the page (or, in our case, computer/phone/tablet screen), as denoted by the circle with the dot. However, note that the thermal profile reverses in the second circle. Therefore, the wind must also reverse and be going INTO the page (or, in our case, computer/phone/tablet screen), as denoted by the "X" with the dot. This wind reversal signifies that the two levels are, in fact, separate entities, even thought they are not technically "separate". Basically, it's a large scale inversion just like the ones that wreck all of Jman's wind events, or at least a lot of them (lol), since the momentum cannot be transported through it, and the layers "decouple" to a degree. Same thing here.

To take this a step further, take a look at the following images taken from the initialization of the GFS Operational at 100 hPa, 70 hPa, 50 hPa, 30 hPa, 20 hPa, and 10 hPa. The black lines denote height, the wind barbs are self explanatory, and the colors are temperature. Pay attention to the wind barbs in the red box in each of the images. Notice how they all start out uniformly westerly/northwesterly at 100 hPa, but then as you look at 70 hPa, 50 hPa, and 30 hPa, there is a clear, albeit much weaker reversal, where the wind goes easterly. Then, the wind starts reversing again at the 20 hPa level, and further at 10 hPa. This helps to show the concept discussed above in real time.









3.  So under relatively stable conditions, or minor changes to the strat you can see direct correlation between where the lowest heights of the SPV live and the TPV live.

I do not fundamentally disagree with you here - if there are no fluxes being added into the system, then conceptually, yes, there's no lagged input to account for, so they should look fairly similar in real time.

4. A change at the strat isnt locked to a 3-6 week lag time when they have been coupled as they have been between 10mb down through 100, and consequently the troposphere.  But as the forecast shows the 10mb nd 50mb SPV is set to de couple as a result of a second even stronger wave of warming beginning at the top 10mb and eventually translating down.

I touched on this in my first point. It isn't a coupling or decoupling that you're looking at, per se'; it's a lagged effect as the heat flux works its way down (or up).

5. I think the warming throughout Dec was such that it weakened the SPV some but actyed more to push it, rather than to strongly weaken it.  There wasnt enough weakening and warming of the vortex itself, just the surrounding ridging acted as an expanding balloon that pushed the vortex over to the wrong side of the hemi.  And because there is some link and has been since the fall the 500mb pattern responded accordingly.

I think our disagreement here is more semantics than anything else. The degree to which we feel that the warming weakened the vortex can be subjective, but we both agree on the same premises - the vortex was weakened to some degree, and it was also shifted equatorward. However, I think there's a reasonable amount of information to say that the Stratospheric vortex has taken a pretty substantial hit. The below is the Euro Ensemble zonal wind forecast initialized at 23rd December. As you can see, the first wave of warming knocked it to the lower red line, which is the 90th percentile (very statistically significant, anomalously weak), and this second warming event will do the same:



And this where I will close out by saying that even though there will likely be no formal reversal, that point is moot, because the reversal is not the cause of what we experience here in the Troposphere; it's a byproduct. The warming itself is what sets the events in motion, because those anomalous fluxes have been working downward over the last few weeks into the troposphere, and now we will start to see the Tropospheric pattern respond.

I hope that all of this made sense, for you and everybody, but if not, let me know and we can take it further

[rb924119]

Folks, this is lunacy:



I don’t like to throw around the word “historic”, but this has the most potential that I can remember ever seeing in a sustained pattern. Why sustained? Look at Europe - that cold is reloading AGAIN, and in a retrograding pattern like we are now getting into, that signals what’s coming here 10-20 days later. I can’t promise you snow in your backyard, but I can tell you that it’s going to be darn far cry from last year. Trust the process, folks, because IT’S COMING.

[rb924119]

Folks, this is lunacy:



I don’t like to throw around the word “historic”, but this has the most potential that I can remember ever seeing in a sustained pattern. Why sustained? Look at Europe - that cold is reloading AGAIN, and in a retrograding pattern like we are now getting into, that signals what’s coming here 10-20 days later. I can’t promise you snow in your backyard, but I can tell you that it’s going to be darn far cry from last year. Trust the process, folks, because IT’S COMING.

Just saying’….

[rb924119]

Folks, this is lunacy:



I don’t like to throw around the word “historic”, but this has the most potential that I can remember ever seeing in a sustained pattern. Why sustained? Look at Europe - that cold is reloading AGAIN, and in a retrograding pattern like we are now getting into, that signals what’s coming here 10-20 days later. I can’t promise you snow in your backyard, but I can tell you that it’s going to be darn far cry from last year. Trust the process, folks, because IT’S COMING.

Just saying’….

A more complete list:



Arguably the greatest winters of any of our lifetimes are on this list (excluded some others such as ‘10-11, ‘13-‘14, and ‘14-‘15 because they were dominated by the Pacific), and we are entering a period lining up to be very, very similar. CP, if this doesn’t get you at least intrigued, then there’s no hope for you, my friend haha

[dsix85]

People on X going crazy with the Euro run.

[dsix85]

People on X going crazy with the Euro run.

[sroc4]

Fantasy storms showing back up in the LR....

Check!

Now lets cont to see them as we head in and under 5-7days.....


We Track!!!!  

[rb924119]

Fantasy storms showing back up in the LR....

Check!

Now lets cont to see them as we head in and under 5-7days.....


We Track!!!!  

January 6th-9th to start

[sroc4]

I also think we can’t let go of 4-5th just yet either. Odds against but 500 isn’t that far away. 12z Cmc yesterday showed just how close it is. It’s all about timing. Southern energy just needs to get out ahead of the northern energy by just a little and we get a phase and neutral to neg tilt in time. Odds are against for now but still enough to watch for the next 24 hrs or so

[rb924119]

I also think we can’t let go of 4-5th just yet either. Odds against but 500 isn’t that far away.  12z Cmc yesterday showed just how close it is. It’s all about timing. Southern energy just needs to get out ahead of the northern energy by just a little and we get a phase and neutral to neg tilt in time. Odds are against for now but still enough to watch for the next 24 hrs or so

Yeah, I agree - I don’t like the ridge placement either; it’s too far east. Close, and we may get some light snow/snow showers associated with the frontal passage, but I think it comes together too late for us.

[rb924119]

12z GFS and GEM are Godzillas for a large portion of this forum between the 6th-8th, details to be determined. Carry on

[uanswer2me]

12z GFS and GEM are Godzillas for a large portion of this forum between the 6th-8th, details to be determined. Carry on

Which portion? I'm 3 miles due east of Philly in New Jersey.

[SENJsnowman]

12z GFS and GEM are Godzillas for a large portion of this forum between the 6th-8th, details to be determined. Carry on

Which portion? I'm 3 miles due east of Philly in New Jersey.

I’ll answer your question over in the banter thread.

[sroc4]

12z GFS and GEM are Godzillas for a large portion of this forum between the 6th-8th, details to be determined. Carry on

Which portion? I'm 3 miles due east of Philly in New Jersey.

I’ll answer your question over in the banter thread.

No need to take that response to Banter snowman.  Just point out that obv at this lead time the details of things like R/S lines and who see what if any are of course subject to change.  Let me set the table for the big picture.  

Currently at the surface the 12z GFS shows a primary cutting into the Ohio valley, before transferring to the coast off the DelMarVa region, +/-, and trecking south of LI.  This results in a nice storm that gives much of the area its first significant accumulating snow between the 6th-8th time frame.    (Do not let the snow map such you in like the blue light to the bug in the summer)  








Now one has to ask ones self does this soln make sense?  In short the answer is a respunding YES...as it stands.  To answer that  in a little detail you have to see if the main ingredients are in place, and to do so that lets look at the 500mb to set the table.  

What you see in this first image is a negative AO, neg NAO, and a 50/50 low.  The AO and NAO in a negative state, ie: ridging in these areas, this allows polar air to be just to our north.  The fact that we have this high latitude blocking in place keeps the 50/50 low, which by the way is the result of the likely swing and miss of the energy coming together too late after passing through between the 4th and 5th, in place long enough to trap a polar HP to our north which in turn forces our primary surface low into the Ohio Valley to transfer to the coast early and south enough to draw in cold air a mature into a winter storm for the North east.




No of course the grain of salt MUST be applied here for this is still 162+ hrs out, and lord knows the best storms have remained in the LR only over the past year or so.  But IMHO a soln that leads to our first winter Nor'easter is real for the period between 6-8th because 1) our MJO has now spent a significant amt of time in phases that are typically cold and snowy in the NE, which gives our -AO/-NAO blocking forecast legitimacy AND 2) there are changes in positioning of the STRAT PV by this time frame that are also typically favorable to allow cold air into the region.  

Our coverage area including the entire coastal plain is 100% in the running here for a nice winter storm, the details of which are still yet to be determined.  Detailed back yard questions should hold off until at least the end of the week.   While I used the GFS, to varying degrees the CMC and Euro are similar both surface and at 500 with of course differences.  No storm or wet storm for some or many are not off the table either so lets keep ourselves in check for now.  

We Track

[toople]

12z GFS and GEM are Godzillas for a large portion of this forum between the 6th-8th, details to be determined. Carry on

Did you think this could trend too far north? I feel like 7 days is forever.

[sroc4]

12z GFS and GEM are Godzillas for a large portion of this forum between the 6th-8th, details to be determined. Carry on

Did you think this could trend too far north?  I feel like 7 days is forever.  

See post above

[toople]

12z GFS and GEM are Godzillas for a large portion of this forum between the 6th-8th, details to be determined. Carry on

Did you think this could trend too far north?  I feel like 7 days is forever.  

See post above

I’m sorry about that. You can delete my post if you want. I’m so embarrassed

[rb924119]

12z GFS and GEM are Godzillas for a large portion of this forum between the 6th-8th, details to be determined. Carry on

Which portion? I'm 3 miles due east of Philly in New Jersey.

I’ll answer your question over in the banter thread.

No need to take that response to Banter snowman.  Just point out that obv at this lead time the details of things like R/S lines and who see what if any are of course subject to change.  Let me set the table for the big picture.  

Currently at the surface the 12z GFS shows a primary cutting into the Ohio valley, before transferring to the coast off the DelMarVa region, +/-, and trecking south of LI.  This results in a nice storm that gives much of the area its first significant accumulating snow between the 6th-8th time frame.    (Do not let the snow map such you in like the blue light to the bug in the summer)  








Now one has to ask ones self does this soln make sense?  In short the answer is a respunding YES...as it stands.  To answer that  in a little detail you have to see if the main ingredients are in place, and to do so that lets look at the 500mb to set the table.  

What you see in this first image is a negative AO, neg NAO, and a 50/50 low.  The AO and NAO in a negative state, ie: ridging in these areas, this allows polar air to be just to our north.  The fact that we have this high latitude blocking in place keeps the 50/50 low, which by the way is the result of the likely swing and miss of the energy coming together too late after passing through between the 4th and 5th, in place long enough to trap a polar HP to our north which in turn forces our primary surface low into the Ohio Valley to transfer to the coast early and south enough to draw in cold air a mature into a winter storm for the North east.




No of course the grain of salt MUST be applied here for this is still 162+ hrs out, and lord knows the best storms have remained in the LR only over the past year or so.  But IMHO a soln that leads to our first winter Nor'easter is real for the period between 6-8th because 1) our MJO has now spent a significant amt of time in phases that are typically cold and snowy in the NE, which gives our -AO/-NAO blocking forecast legitimacy  AND 2) there are changes in positioning of the STRAT PV by this time frame that are also typically favorable to allow cold air into the region.  

Our coverage area including the entire coastal plain is 100% in the running here for a nice winter storm, the details of which are still yet to be determined.  Detailed back yard questions should hold off until at least the end of the week.   While I used the GFS, to varying degrees the CMC and Euro are similar both surface and at 500 with of course differences.  No storm or wet storm for some or many are not off the table either so lets keep ourselves in check for now.  

We Track

We should start calling you Picasso, because this is a work of art seriously, though, great synopsis.

To @toople ‘s question, and to piggyback off your post, Scott, I don’t foresee this trending too warm, at least for a lot of us. I’ll have to do a more detailed check, but I think this should end up taking a track that’s pretty optimal for most of this forum, and it may even end up centering along I-95. That said, we will probably see the classic windshield wiper effect, where the models will start trying to hold onto the primary too long and take it up into western PA/NY, only to back off again toward a similar solution to what we are seeing now within three days as the models properly account for the influence of the blocking.

[sroc4]

12z GFS and GEM are Godzillas for a large portion of this forum between the 6th-8th, details to be determined. Carry on

Did you think this could trend too far north?  I feel like 7 days is forever.  

See post above

I’m sorry about that.  You can delete my post if you want. I’m so embarrassed

No worries at all. You posted literally 1min after I posted. Lol

[tomsriversnowstorm]

RB I understand everyone is focusing on next weekend. However, I am curious how the pattern looks after that into January. Is this our shot this weekend or does January have a shot to stay cold still?

[rb924119]

RB I understand everyone is focusing on next weekend. However, I am curious how the pattern looks after that into January. Is this our shot this weekend or does January have a shot to stay cold still?

In my opinion, this is only the beginning. We may have a pattern reload or two when it “relaxes” a bit, as that is pretty typical, but I think we predominantly rock and roll right into March on the whole.

[rb924119]

RB I understand everyone is focusing on next weekend. However, I am curious how the pattern looks after that into January. Is this our shot this weekend or does January have a shot to stay cold still?

In my opinion, this is only the beginning. We may have a pattern reload or two when it “relaxes” a bit, as that is pretty typical, but I think we predominantly rock and roll right into March on the whole.

[jmanley32]

So great to even just see a storm on the mid range, someone posted that the 12z Euro was crazy? What did it show was it similar to GFS. The surface trend from the GFS is interesting, the snow map haws markedly continued to push north starting from south of DC to now keeping southern jersey out, long way to go but couldn't ask for much more to be potenytially tracking a storm in the first week of the new year. Now yes I know I have been negative about this year but after reading these posts I think there is some hope for next weekend and if it plays out verbatim will stomp last years 5 inches and might even top my call for snowfall in NYC lol, I will be glad to be wrong on that one. Going to be a very busy week as I will be coming off a 10 day vacation (much needed) so hopefully the week will fly by and that we will still be seeing this come mid-week to the weekend. Happy new years to all.

[heehaw453]

Regarding 1/7/ threat, Like SROC has nicely pointed out the H as shown in the EPS provides a mechanism for colder air transport before the storm. That's huge and one of the things you look for when talking about significant snow potential. The 50/50 L causes that H to get pinned and the 50/50 low is pinned by the Greenland blocking. It's text book for a nice snowfall event in these parts. The caveat is if the storm amplifies too much then it will tend to push very close to the coast if not slightly inland. That would warm the mid-levels enough for rain especially on the coastal plain. The amplification will probably be determined by the amount of jet stream phasing that occurs with the storm as well as the initial strength of the s/w.

As of now i think regional wide snow accumulations are looking decent with the best chance of substantial accumulations (4"+) in the interior due to the risk of an over amplified storm causing mixing/rain on the coastal plain.

[Sponsored content]