Jan 20-24 storm window opens (Jan 22 potential)

[Typhoon Tip]

 Looks pretty straight forward actually... but still a thing of beauty. 

 

The teleconnectors are in relay.  The EPO is crashing and sets the table with a massive cold insert into Canada.  All operational runs and for the most part, their majority ensembles show a marked cooling over the Canadian shield over the next 5 days as ridging in the far NE Pac punches enough inland to really tip the deep layer flow SE/SSE over western Canada.   

 

This teleconnects with a negative anomaly (SPV genesis) in C/S Canada - the exotic depths of which are probably being assisted along by a well-timed -NAO pulse;  the EPO and NAO thus dual exert on the deep layer medium and a huge anomaly results.   

 

This activity precedes the PNA changing by a week's ~ lag.  During the former reign, it becomes less likely that a major precipitation event will unfold because of the intense suppressive influence by the SPV anomaly.   However, during the ~ 20-24th ... if all goes according to plan, the EPO and NAO weaken some in their negative modes; the SPV thus weakens to an open L/W.    Meanwhile the PNA rises some 5 SD in the 7 to 10 days leading.  

 

 

Particularly in the ESRL channel (top left) this is true.   The NCEP, as noted yesterday, will tend to play catch-up; but even here, there is an impressive PNA recovery.  Both throw a large Archambaultian signal here as a mean, and seeing as the NAO and SPV relax some, the larger mass fields should enter a period of important cyclogenesis.   Granted, this does not have to be along the East Coast, however, climatology favors.

 

I would yellow the 18 and 19th, and then go red for the 20th ... 21st - 24th.  

 

The reason I put KU in the title is because I do see this being more MA and NE in nature, given to the magnitude of antecedent cold next week supplying a deeper ambient baroclinic push down the eastern part of the Continent.  The PNA may not even be recovered entirely to 0.0 when the fuse is lit on this.  In rise, western heights may become antithetic to the MJO's whopper Phase 6 loop-back, which is highly suspect to loop a wave of that intensity - usually they die off a bit before reprocessing to a retrograde phase.  We'll see on that... But clearly there are other processes trying to overcome in the Pacific, and the burgeoning +PNA signal over the next 10 days would tend to break toward cyclogenesis given to the anomalous cold and antecedent gradient in the OV-MA regions.   

 

Stay tuned!

[CoastalWx]

Something is definitely flagged around that time, agreed.  It may be offshore, but there are enough signs to make you go hmm.

[HM]

I don't know man; I think it is going to be tough. The fast flow and lack of real North Atlantic blocking may keep things too progressive and out to sea. Perhaps eastern New England can get a good clipping. We are going to need a northern s/w that goes to town and amplifies quickly enough under the PV (Feb 06?). Feb 06 was a classic MJO-stratospheric coupling scenario.

[Typhoon Tip]

I don't know man; I think it is going to be tough. The fast flow and lack of real North Atlantic blocking may keep things too progressive and out to sea. Perhaps eastern New England can get a good clipping. We are going to need a northern s/w that goes to town and amplifies quickly enough under the PV (Feb 06?). Feb 06 was a classic MJO-stratospheric coupling scenario.

 

I wouldn't worry about that... 

[Typhoon Tip]

Update:

 

Much of the impetus in starting this KU thread is based upon the relaxation in the flow.  The polarward indices as provided by CPC and CDC overnight still suggest that the SPV should weaken in about a week.   More importantly, a robust rise in the PNA at just the right spatial-temporal interval takes place.   That could all well mean a better western ridge push- a lowering of heights over the deep SE would teleconnect at that time.   

 

The operational GFS run at 12z hints at this pretty loudly - I think the threat is real, and may come into better focus, operationally.  Obviously we are 9+ days away.  But in a general synoptic mechanical sense we'd want to watch for a "subsume" scenario.  

 

I've described that in the past, but what that means is when you have a Pac or intermediate stream S/W passing S of a remnant SPV fragment over southern Canada, and the S/W induces said fragmentation to slip S in a phase.   I would think having a waning SPV with a PNA pulse timed well might be a good canvas/start for setting that sort of table.   

 

Or not ... we'll see -     20th-24th.   Even if that particular type of phasing doesn't materialize, I still see this kind of concerted PNA rise in the CPC members, occurring during antecedent polar outbreak, as cyclogenetic through the overall medium:

 

[CoastalWx]

GEFS like day 10. They take advantage of that ridge and drop some energy down into the plains. Would likely be a Miller B deal..if any.

[OSUmetstud]

I'm not sure if we have the right -NAO signature for a KU.  Also, the flow continues to be quite fast in the medium/extended as HM alluded to...which makes it difficult for amplification/phasing.

[CoastalWx]

I'm not sure if we have the right -NAO signature for a KU.  Also, the flow continues to be quite fast in the medium/extended as HM alluded to...which makes it difficult for amplification/phasing.

 

Yeah I'm not looking at it from a KU point of view...but something that could be a factor in eastern SNE anyways.

[OSUmetstud]

Yeah I'm not looking at it from a KU point of view...but something that could be a factor in eastern SNE anyways.

 

yeah me either.

 

Even though their is a bit of ridging into northern Greenland...the Atlantic looks distinctively non-negative NAO.

 

You would generally see low heights extending outward through that Atlantic ridge in an effective -NAO.

 

[Typhoon Tip]

I'm not sure if we have the right -NAO signature for a KU.  Also, the flow continues to be quite fast in the medium/extended as HM alluded to...which makes it difficult for amplification/phasing.

 

Firstly, too -NAO reliant;  it's not a prerequisite environmental variable.    

 

2ndly, hense the "relaxation of the flow" - out in time, the flow slows, AS the PNA spikes.   Objectively, many operational guidance have entered a hint that there something to this analysis and we'll see how this evolves.   

[Typhoon Tip]

It occurs to me -  there are probably some differing opinions on what is meant by "KU Storm".   It's not in the officially recognized AMS glossary of terms;  it's a phrase founded upon the published works of Kocin and Uccellini (chk spelling).   I have the books.  

 

Still, so as to avoid any semantic entanglements I've changed the title of this to just storm.  That way, we won't offend anyone's delicate sensibilities or opinions about what counts as a KU storm.

 

For me, it's less about demographic impact and more about atmospheric constructs identifiable/causal.   Demographics are important, but there is their NESDIS scale, which considers that.  

[H2Otown_WX]

Yeah I'm not looking at it from a KU point of view...but something that could be a factor in eastern SNE anyways.

Talk me off the ledge.

[powderfreak]

It occurs to me - there are probably some differing opinions on what is meant by "KU Storm". It's not in the officially recognized AMS glossary of terms; it's a phrase founded upon the published works of Kocin and Uccellini (chk spelling). I have the books.

I am fairly certain most posters on here are familiar with what a KU storm is and what that mention implies.

[Typhoon Tip]

I am fairly certain most posters on here are familiar with what a KU storm is and what that mention implies.

 

Okay, then what? 

 

that's why I changed the title to storm, because I am not sure what that "implication" means, seeing as it's not official

[ORH_wxman]

A -NAO is not required for a KU in a -EPO/+PNA pattern for New England.

 

 

A phase change from + to - is classic in this pattern for a KU....but not sure if that will happen...but just throwing it out there. Jan 2005 had a big +NAO leading up to it and it was a true Archambault Event where the NAO goes from + to -. That is a true Archambault Event...going from - to + is not...that is a reverse Archambault Event as I like to call it....it favors snow, but it is not a big precipitation indicator....its just that if you have a storm signal there, it is extremely often snow.

[Typhoon Tip]

A -NAO is not required for a KU in a -EPO/+PNA pattern for New England.

 

 

A phase change from + to - is classic in this pattern for a KU....but not sure if that will happen...but just throwing it out there. Jan 2005 had a big +NAO leading up to it and it was a true Archambault Event where the NAO goes from + to -. That is a true Archambault Event...going from - to + is not...that is a reverse Archambault Event as I like to call it....it favors snow, but it is not a big precipitation indicator....its just that if you have a storm signal there, it is extremely often snow.

 

Agreed!  but ... if that period of time is going to be successful with a "storm", the wild card is flow relaxation.  The PNA could rise, but if the SPV remains too dominant, eh -

[OSUmetstud]

Agreed!  but ... if that period of time is going to be successful with a "storm", the wild card is flow relaxation.  The PNA could rise, but if the SPV remains too dominant, eh -

 

isn't that what I said above...the thing you disagreed with?

[Typhoon Tip]

isn't that what I said above...the thing you disagreed with?

 

 

not exactly.   don't want to get into a semantic debate, but ...i am discussing the probability of the flow relaxation and what that could lead too - you guys "appear" to assume it doens't.

 

different things -

[OSUmetstud]

not exactly.   don't want to get into a semantic debate, but ...i am discussing the probability of the flow relaxation and what that could lead too - you guys "appear" to assume it doens't.

 

different things -

 

I'm not saying it can't...it's just a thing that could go wrong.

[Typhoon Tip]

I'm not saying it can't...it's just a thing that could go wrong.

 

Well yeah, definitely  -  it's predicated on that.   

 

What's weird, the 12z Euro is really biting on the scenario but you can see that it rides the tightrope between the two.  I tell you what ... if heights over MIA fall another 4 DM prior to the SW getting to 90w in that solution.   

[Edge Weather]

Tip, 

 

The Euro Control run  on Accu-weather has your KU this morning for next Tuesday, and it is a thing of beauty.  You can definitely see the potential on this morning's Euro run, but it just misses.  The Control run brings home the goods in a BIG way.  I posted the following in the New York forum earlier today: 

 

Euro Control run this morning bombs the storm out next Tuesday into a major Nor'easter, developing it near the Virginia Capes as a 996mb at 198 hrs, then taking to to just off Asbury Park as a 982mb low at 204 hrs, then to Cape Cod as a 974mb low. 850's are amazingly cold, right off the coast and south of Long Island so everyone is snow. It shows around a foot of snow for everyone with nice wrap-around. It is a thing of beauty.  At the height of the storm it has the 850 temps at -10 to -20 just to the west of NYC and almost into NYC and surface temps in the single digits.  So, verbatim, this would most likely be a high ratio snow too, so the amount I gave was probably too low.  Of course, who knows if this will happen, but Tip in the New England forum has been talking about the possibility of a KU on this day for quite some time now, and verbatim, this model shows probably 1-2 feet for NYC and vicinity.  And, yes I know it is just one model, but this model did nail the October 29, 2011 snowstorm very well in our area, even better than the operational run, so who knows?

[Typhoon Tip]

Tip, 

 

The Euro Control run  on Accu-weather has your KU this morning for next Tuesday, and it is a thing of beauty.  You can definitely see the potential on this morning's Euro run, but it just misses.  The Control run brings home the goods in a BIG way.  I posted the following in the New York forum earlier today: 

 

Euro Control run this morning bombs the storm out next Tuesday into a major Nor'easter, developing it near the Virginia Capes as a 996mb at 198 hrs, then taking to to just off Asbury Park as a 982mb low at 204 hrs, then to Cape Cod as a 974mb low. 850's are amazingly cold, right off the coast and south of Long Island so everyone is snow. It shows around a foot of snow for everyone with nice wrap-around. It is a thing of beauty.  At the height of the storm it has the 850 temps at -10 to -20 just to the west of NYC and almost into NYC and surface temps in the single digits.  So, verbatim, this would most likely be a high ratio snow too, so the amount I gave was probably too low.  Of course, who knows if this will happen, but Tip in the New England forum has been talking about the possibility of a KU on this day for quite some time now, and verbatim, this model shows probably 1-2 feet for NYC and vicinity.  And, yes I know it is just one model, but this model did nail the October 29, 2011 snowstorm very well in our area, even better than the operational run, so who knows?

 

1234abc   ...  is that Swedish ?

 

Um, interesting.  I don't of course have any experience in using any such tool, therefore no intuitive correction borrowed from historical performance nuances/biases, can be applied - so I take your word for it.   

 

The others ..HM, OSU' et al, make a good point about the speed of the flow.  It may be that the models are having a tougher time focusing on that time period in question, not just because it's an extended lead, but because it's like ...trying to hit a fast moving target from a long distance away (so to speak).  If the flow were a bit more relaxed already, a stronger physical presence, in the form of a sufficient upstream perturbation in the field, might be processed/seen more clearly. 

 

If there is any truth to that notion (weak analogy or not...),  that would nicely explain why every cycle of the operational GFS, going back days at this point, has large closed sfc circulation, albeat weak, but doing so centered on the 22-24th time frame(s).   Also, it's doing so on the leading edge of a rather strong cold deep layer thickness push into the OV/TV longitudes/latitudes, which flags a period of heightened baroclinicity will be in place near the Gulf Stream interface with the continental cP air.   Given that actually taking place, the low it has, as is, might simply be a response to the intense numerical instability the former concept introduces through that region.   In other words, it would not take much to detonate something more important. 

 

There is another component to all this that I am monitoring in the Global models; it has to do with static heights and balanced geostrophic winds over Florida and adjacent N Gulf and SE Coastal waters.   UKMET and ECM from 00z demo this regionally well ... The heights are more than 582dm over central Florida.  In the past, I have used that as a rough guideline for whether S/Ws can survive a pass through the latitudes of the TV, without the background flow being too aggressive - causing it to be damped/smoothed/absorbed, more than an effective storm producing impulse.    On the UKMET for example, the main impulse at 144 hours was located up over western/SW Canada, at that point in, the heights over Florida are already down to 576dm;  that is certainly intriguing suggestion that the Canadian impulse may dig and maintain it mechanical presence in the flow down into those latitudes.   Time will tell...

[Edge Weather]

Hi Tip,

 

The Euro Control run is basically the main ensemble member of the European operational run, similar to the ensemble member 1 of the GFS.  It usually looks very similar to the operational run but occasionally looks different and when it looks different it sometimes means it is on to something, and sometimes it doesn't.  What is interesting is that it takes the clipper on the same track as the operational run but bombs it out instead.  Going out in time that far though, it does show the potential.  

[Typhoon Tip]

Hi Tip,

 

The Euro Control run is basically the main ensemble member of the European operational run, similar to the ensemble member 1 of the GFS.  It usually looks very similar to the operational run but occasionally looks different and when it looks different it sometimes means it is on to something, and sometimes it doesn't.  What is interesting is that it takes the clipper on the same track as the operational run but bombs it out instead.  Going out in time that far though, it does show the potential.  

 

Interesting ... welp, we shall see how that compares to the version made public coming out shortly - 

[OKpowdah]

My problem with forecasting any notable snow events for New England during this period is that I don't see much of a mechanism for enough amplification of a shortwave upstream to handle the fast flow south of the PV.

[Edge Weather]

Looks like the Euro took one step closer to this morning's control run.  Not there yet, but really close.  

[Baroclinic Zone]

Weekend clipper, as modeled on the 1/14 12z Euro, bombs off the coast of Maine.  Will need to watch that system, and than the follow up shortwave as it drops into the trough,  System will form somewhere, will it be close enough to the coast?

[Baroclinic Zone]

Weekend clipper, as modeled on the 1/14 12z Euro, bombs off the coast of Maine.  Will need to watch that system, and than the follow up shortwave as it drops into the trough,  System will form somewhere, will it be close enough to the coast?

 

Also, 5h looks eerily similar to Jan 2005.

[Typhoon Tip]

My problem with forecasting any notable snow events for New England during this period is that I don't see much of a mechanism for enough amplification of a shortwave upstream to handle the fast flow south of the PV.

 

 

I dunno - the 180 hour GONAPS looks reeeeallly good   ahahhahha

[Baroclinic Zone]

Here you go John,  Todays 12z Euro.