Re: Long Range Thread 28.0

[SENJsnowman]

EPS has some bombs for 2/13

Good n/s interaction.

Hello My Pretty! 🥰

[nutleyblizzard]

Very tricky setup with the Feb. 12/13 threat. The Euro Op run is a southern slider, but this needs to be watched. Like Heehaw said it’s all about the timing with the northern and southern energies. My gut tells me it’s unfortunately one of those all or nothing events, and with our luck lately I’m not feeling very confident.

[dkodgis]

CRY HAVOC AND LET SLIP THE DOGS OF WAR!!!

Model mayhem.

I say we are all due for a bit of luck

[heehaw453]

I normally don't show Op surface maps at this range. I do believe based on what the setup is there is this kind of upside. To Nutley's point boom or bust with this. The h5 though I believe colder solutions will prevail. May not be decent snows if phasing is off.

[heehaw453]

I like where things are at for D6. Closing off ULL with it being given a bit of Red Bull as it hits the coast from the n/s.  There's potential here folks. This will go colder IMO as we get closer and potential for stalling. Hopefully things hold, but track worthy for now IMO...

[heehaw453]

Data continues to show favorability. Hopefully this is something to kick start the pattern.

GEFS teleconnection for 2/12
AO -1.25 falling rapidly
EPO -.5 falling rapidly
NAO ~-2 steady
PNA +.75 rising rapidly

It's also about trajectory with teleconnections.

GEFS Bias corrected MJO


SOI

[heehaw453]

Also this storm has plenty of cold air getting wrapped around its backside. That's clear and the PNA ridge will aide that on the split flow. Make no mistake if it deepens the mid-levels will crash as its core full of cold air and there is cold air to our NW pushing down.  The other point the ULL will probably exit off Delmarva as it came ashore in Bay Area.

[MattyICE]

Also this storm has plenty of cold air getting wrapped around its backside. That's clear and the PNA ridge will aide that on the split flow. Make no mistake if it deepens the mid-levels will crash as its core full of cold air and there is cold air to our NW pushing down.  The other point the ULL will probably exit off Delmarva as it came ashore in Bay Area.

Norm Macdonald rule?? Love it. I specifically like your idea about the colder air wrapping in. I think more and more a straight cutter is likely slipping off the table. That may have been better to reinforce the Greenland block more quickly, but retrograding Scandinavian blocking is more classic anyhow. I think even if a lot of the area starts as rain it can switch over in time for it to matter. There should theoretically only be so much it can gain latitude before shunted to the east.

[heehaw453]

Yeah Matty. No cutter with this one IMHO. The Euro last night was a step a away from a nuke.  If the ULL can close off before it hits the coast folks will be seeing this storm in a new light. The issue is it's a bit disorganized as it's approaching the coast and that allows its mid-levels to spread additional warmth as the storm approaches the area. That's my key now is can we get a proper phase and the southern stream closes off in time. If that happens snow deficits will be closing around here, but if not still think the area can see a few inches.

[sroc4]

Also this storm has plenty of cold air getting wrapped around its backside. That's clear and the PNA ridge will aide that on the split flow. Make no mistake if it deepens the mid-levels will crash as its core full of cold air and there is cold air to our NW pushing down.  The other point the ULL will probably exit off Delmarva as it came ashore in Bay Area.

Here are most of the major players.  As heehaw stated there are big picture players out over the pacific that justify us even talking about this as a potential.  The SOI crash is legit, strong neg for now 10days.  THIS is a major signal for a shake up to the atmosphere is underway, and cold is coming for the eastern third of the CONUS.  The MJO is also on its way, if not already when you look at the OLR maps actually, into phase 8 which 100% supports a colder soln in the east.  The MJO and the SOI are intimately linked, and adds another feather in the cap that supports a winter storm for the 12-14th time frame, as well as the potential for a more sustained colder pattern.  BUT The question is still what about IMBY for the 12th-14th??








Here are the flys in the ointment that will determine the IMBY questions.  All three maps, Euro/cmc/gfs are valid images for Saturday eve 10pm.

n/s = northern stream,
s/s = southern stream

These two pieces are what heehaw has been discussing.  The n/s is the red bull Heehaw talked about a post or two above.  Timing and positioning of both of these are critical.  What's going to determine these details?

First the Northern Atlantic.  This area of energy is the 50/50-ISH low that will slow things down to allow these two pieces to interact.  But the strength and positioning of the 50/50-ish low is the first extremely important factor in determining the when and how the n/s and s/s stream interact.
 
Second the ridge along the west coast that I outlined and show the ridge axis with the black arrow.  All three models show it going up as we approach the time of the maps I posted.  This is what allows the n/s energy to dig into the conus, and POTENTIALLY open the gates to the cold air source and add energy IF they interact at the right times.  It is critical that the s/s energy gets out ahead of the n/s, but not too much.  This allows the back side entry and tilts our heights up the coast.  However, if the s/s is in line with or slight behind the n/s energy or if the n/s is not allowed to dig enough then it will act as a steering mechanism that brings the system OTS and minimal cold air involvement in which case you get a system that either slips off to to our south or we see the N edge of the precip shield but it isnt cold enough to make a huge potential, esp for the coastal plain.    

Now what could lead to less n/s digging and or throw off the timing of the n/s will be the small area of vorticity I circled just off the west coast out over the Pac.  This piece on all three models is there with subtle yet import differences in its timing, positioning and strength.  On all models this piece of energy seems to be undercutting the WC ridge to a degree as it comes ashore and begins to knock down the ridge to varying degrees.  This LIKELY WILL play a factor, for better or worse.  The positioning and strength of the 50/50-ish low; however, is a mechanism, that could negate some of these effects.

Again the full details of ALL the key points I highlighted above will be important.  FACT:  the pattern IS DEF on its way to a fundamental change that will allow multiple opportunities between the 12-4th thorugh at leat the end of the month.  Fiction: We know for a fact that your back yard will reap the benefits of this regarding white gold.  Truth is we just dont know, but.....


WE TRACK!!  

[heehaw453]

06Z EPS is an absolute beast. I would say if we don't get something out of this in peak climo with NAM/Atlantic and PAC like that then that is really really unfortunate. Also don't get too detailed on thermal profiles yet. They will change frequently with consolidation/placement of the mid-levels.

[sroc4]

[quote="sroc4"]

Also this storm has plenty of cold air getting wrapped around its backside. That's clear and the PNA ridge will aide that on the split flow. Make no mistake if it deepens the mid-levels will crash as its core full of cold air and there is cold air to our NW pushing down.  The other point the ULL will probably exit off Delmarva as it came ashore in Bay Area.

Here are most of the major players.  As heehaw stated there are big picture players out over the pacific that justify us even talking about this as a potential.  The SOI crash is legit, strong neg for now 10days.  THIS is a major signal for a shake up to the atmosphere is underway, and cold is coming for the eastern third of the CONUS.  The MJO is also on its way, if not already when you look at the OLR maps actually, into phase 8 which 100% supports a colder soln in the east.  The MJO and the SOI are intimately linked, and adds another feather in the cap that supports a winter storm for the 12-14th time frame, as well as the potential for a more sustained colder pattern.  BUT The question is still what about IMBY for the 12th-14th??








Here are the flys in the ointment that will determine the IMBY questions.  All three maps, Euro/cmc/gfs are valid images for Saturday eve 10pm.

n/s = northern stream,
s/s = southern stream

These two pieces are what heehaw has been discussing.  The n/s is the red bull Heehaw talked about a post or two above.  Timing and positioning of both of these are critical.  What's going to determine these details?

First the Northern Atlantic.  This area of energy is the 50/50-ISH low that will slow things down to allow these two pieces to interact.  But the strength and positioning of the 50/50-ish low is the first extremely important factor in determining the when and how the n/s and s/s stream interact.
 
Second the ridge along the west coast that I outlined and show the ridge axis with the black arrow.  All three models show it going up as we approach the time of the maps I posted.  This is what allows the n/s energy to dig into the conus, and POTENTIALLY open the gates to the cold air source and add energy IF they interact at the right times.  It is critical that the s/s energy gets out ahead of the n/s, but not too much.  This allows the back side entry and tilts our heights up the coast.  However, if the s/s is in line with or slight behind the n/s energy or if the n/s is not allowed to dig enough then it will act as a steering mechanism that brings the system OTS and minimal cold air involvement in which case you get a system that either slips off to to our south or we see the N edge of the precip shield but it isnt cold enough to make a huge potential, esp for the coastal plain.    

Now what could lead to less n/s digging and or throw off the timing of the n/s will be the small area of vorticity I circled just off the west coast out over the Pac.  This piece on all three models is there with subtle yet import differences in its timing, positioning and strength.  On all models this piece of energy seems to be undercutting the WC ridge to a degree as it comes ashore and begins to knock down the ridge to varying degrees.  This LIKELY WILL play a factor, for better or worse.  The positioning and strength of the 50/50-ish low; however, is a mechanism, that could negate some of these effects.

Again the full details of ALL the key points I highlighted above will be important.  FACT:  the pattern IS DEF on its way to a fundamental change that will allow multiple opportunities between the 12-4th thorugh at leat the end of the month.  Fiction: We know for a fact that your back yard will reap the benefits of this regarding white gold.  Truth is we just dont know, but.....


WE TRACK!!  

Just so folks can see the big picture, as of the 6z GFS initialization this am this is where the current positions of where the energy that will be our "n/s" and "s/s" energy currently sits way out over the Pac, and where the two pieces of energy that will combine to form our 50/50 energy as we head through the weekend. We have a little time before we sort through some of the finer details so def dont get too caught up in any one surface soln as the week progresses. By Saturday the pieces all come onshore and together.

[billg315]

12z GFS rolling, let's see what it says. Inside of 6 days now, so it's getting to "go-time" on this model tracking.

[MattyICE]

Rain for most on 12z GFS OP - but as hard as it truly tries to classically “cut” it can’t. It ends up still transferring to the coast just too late for many of us. I think it’s still “fixable” for the NYC metro. Wouldn’t take much at this lead time. It’s also just nice to see a juiced up storm to kick off the pattern. May rain in peoples backyards but could end up a worthy sacrifice towards a better outcome as the pattern matures later in the period.

[heehaw453]

Also this storm has plenty of cold air getting wrapped around its backside. That's clear and the PNA ridge will aide that on the split flow. Make no mistake if it deepens the mid-levels will crash as its core full of cold air and there is cold air to our NW pushing down.  The other point the ULL will probably exit off Delmarva as it came ashore in Bay Area.

Here are most of the major players.  As heehaw stated there are big picture players out over the pacific that justify us even talking about this as a potential.  The SOI crash is legit, strong neg for now 10days.  THIS is a major signal for a shake up to the atmosphere is underway, and cold is coming for the eastern third of the CONUS.  The MJO is also on its way, if not already when you look at the OLR maps actually, into phase 8 which 100% supports a colder soln in the east.  The MJO and the SOI are intimately linked, and adds another feather in the cap that supports a winter storm for the 12-14th time frame, as well as the potential for a more sustained colder pattern.  BUT The question is still what about IMBY for the 12th-14th??








Here are the flys in the ointment that will determine the IMBY questions.  All three maps, Euro/cmc/gfs are valid images for Saturday eve 10pm.

n/s = northern stream,
s/s = southern stream

These two pieces are what heehaw has been discussing.  The n/s is the red bull Heehaw talked about a post or two above.  Timing and positioning of both of these are critical.  What's going to determine these details?

First the Northern Atlantic.  This area of energy is the 50/50-ISH low that will slow things down to allow these two pieces to interact.  But the strength and positioning of the 50/50-ish low is the first extremely important factor in determining the when and how the n/s and s/s stream interact.
 
Second the ridge along the west coast that I outlined and show the ridge axis with the black arrow.  All three models show it going up as we approach the time of the maps I posted.  This is what allows the n/s energy to dig into the conus, and POTENTIALLY open the gates to the cold air source and add energy IF they interact at the right times.  It is critical that the s/s energy gets out ahead of the n/s, but not too much.  This allows the back side entry and tilts our heights up the coast.  However, if the s/s is in line with or slight behind the n/s energy or if the n/s is not allowed to dig enough then it will act as a steering mechanism that brings the system OTS and minimal cold air involvement in which case you get a system that either slips off to to our south or we see the N edge of the precip shield but it isnt cold enough to make a huge potential, esp for the coastal plain.    

Now what could lead to less n/s digging and or throw off the timing of the n/s will be the small area of vorticity I circled just off the west coast out over the Pac.  This piece on all three models is there with subtle yet import differences in its timing, positioning and strength.  On all models this piece of energy seems to be undercutting the WC ridge to a degree as it comes ashore and begins to knock down the ridge to varying degrees.  This LIKELY WILL play a factor, for better or worse.  The positioning and strength of the 50/50-ish low; however, is a mechanism, that could negate some of these effects.

Again the full details of ALL the key points I highlighted above will be important.  FACT:  the pattern IS DEF on its way to a fundamental change that will allow multiple opportunities between the 12-4th thorugh at leat the end of the month.  Fiction: We know for a fact that your back yard will reap the benefits of this regarding white gold.  Truth is we just dont know, but.....


WE TRACK!!  

Just so folks can see the big picture, as of the 6z GFS initialization this am this is where the current positions of where the energy that will be our  "n/s" and "s/s" energy currently sits way out over the Pac, and where the two pieces of energy that will combine to form our 50/50 energy as we head through the weekend.   We have a little time before we sort through some of the finer details so def dont get too caught up in any one surface soln as the week progresses.  By Saturday the pieces all come onshore and together.  


 

Agree 100%. Moving parts abound and too early for specifics. However, I think there needs to be some n/s that sneaks out ahead of the s/s for the air mass and keep this southern piece from riding too far north. As shown this won't work here as the air mass is too warm initially and this is a CNE special. What I was seeing before is more confluence over NE. There has to be enough resistance to keep this storm to bomb off Delmarva and LI. This is going to be a powerful storm most likely and it would be a damn shame to waste it.

[heehaw453]

Rain for most on 12z GFS OP - but as hard as it truly tries to classically “cut” it can’t. It ends up still transferring to the coast just too late for many of us. I think it’s still “fixable” for the NYC metro. Wouldn’t take much at this lead time. It’s also just nice to see a juiced up storm to kick off the pattern. May rain in peoples backyards but could end up a worthy sacrifice towards a better outcome as the pattern matures later in the period.

It needs more resistance to the north. I would like a little n/s to sneak out ahead of the s/s to prevent that and also facilitate cooling the antecedent air mass. Can't waste a bomb like this in peak climo. No how no way.

[billg315]

12Z GFS showing transfer to coastal Low taking place but it looks like with upper levels closing off a little too late and a little too "tucked" right over New Jersey so goes over to snow on the backside but still primarily a rain event.  If that coastal pops a little earlier and a little further south/east of the GFS modeling, I think we could be in good shape. On the 0z Euro the Low pops around the southern Delmarva, which is where I think we would want it -- hence the more impressive snow output on the Euro.
Also curious for heehaw and sroc's thoughts (and this may have been covered earlier in the thread at a point I didn't read) with regard to the fact that it doesn't appear to me that we have a strong High over eastern Canada. Am I correct in that? And if so does that deprive us of A. a better cold air source, and B. allow the Low to get further north (which is not good for us)?

[sroc4]

Rain for most on 12z GFS OP - but as hard as it truly tries to classically “cut” it can’t. It ends up still transferring to the coast just too late for many of us. I think it’s still “fixable” for the NYC metro. Wouldn’t take much at this lead time. It’s also just nice to see a juiced up storm to kick off the pattern. May rain in peoples backyards but could end up a worthy sacrifice towards a better outcome as the pattern matures later in the period.

It needs more resistance to the north. I would like a little n/s to sneak out ahead of the s/s to prevent that and also facilitate cooling the antecedent air mass. Can't waste a bomb like this in peak climo. No how no way.

If you guys look closely on this run the 50/50-ish position is a tad too far north.  There is too much space between the 50/50 and the system.  With the system being so amped and phasing with the n/s the poor wave spacing allows to much height amplification out ahead leading to the tucked track.  In this scenario if the 50/50 was even a 100-200 miles further south and west it would not have allowed for the primary to get that far N

[sroc4]

12Z GFS showing transfer to coastal Low taking place but it looks like with upper levels closing off a little too late and a little too "tucked" right over New Jersey so goes over to snow on the backside but still primarily a rain event.  If that coastal pops a little earlier and a little further south/east of the GFS modeling, I think we could be in good shape. On the 0z Euro the Low pops around the southern Delmarva, which is where I think we would want it -- hence the more impressive snow output on the Euro.
Also curious for heehaw and sroc's thoughts (and this may have been covered earlier in the thread at a point I didn't read) with regard to the fact that it doesn't appear to me that we have a strong High over eastern Canada. Am I correct in that? And if so does that deprive us of A. a better cold air source, and B. allow the Low to get further north (which is not good for us)?

IMO the cold air will come from the digging n/s energy and the 50/50 MUST be in good position to create confluence as the primary trys to cut.  W/O strong confluence over the NE the amplified nature of a phasing system will allow to much height amplification and warm sectoring, of the coastal plain at the very least, out ahead of the primary.

[sroc4]

Obv it goes without saying that we have to keep expectations in check as there are so many ways for which this can turn sour for some, or many.

[heehaw453]

12Z GFS showing transfer to coastal Low taking place but it looks like with upper levels closing off a little too late and a little too "tucked" right over New Jersey so goes over to snow on the backside but still primarily a rain event.  If that coastal pops a little earlier and a little further south/east of the GFS modeling, I think we could be in good shape. On the 0z Euro the Low pops around the southern Delmarva, which is where I think we would want it -- hence the more impressive snow output on the Euro.
Also curious for heehaw and sroc's thoughts (and this may have been covered earlier in the thread at a point I didn't read) with regard to the fact that it doesn't appear to me that we have a strong High over eastern Canada. Am I correct in that? And if so does that deprive us of A. a better cold air source, and B. allow the Low to get further north (which is not good for us)?

IMO the cold air will come from the digging n/s energy and the 50/50 MUST be in good position to create confluence as the primary trys to cut.  W/O strong confluence over the NE the amplified nature of a phasing system will allow to much height amplification and warm sectoring, of the coastal plain at the very least, out ahead of the primary.

100% agree. I think the blocking will pinch the 50/50 a bit more south west. Matter of fact I like seeing amped solution now because I think the reality will be not quite as amped. Models have a tendency to go extremes at this range only to pull back as the fidelity of the data increases.

[DAYBLAZER]

Fantastic discussion everyone. Really educational. Happy to see some activity on the board, things certainly have been bleak.

From a purely non-scientific point of view, I'll say this: I am perfectly content (perhaps even pleased) that models are not throwing out consensus 'bullseye' target hits for our area at this juncture. For the past few years, it seems that every storm that gives us those big hits on LR guidance 5-7 days out almost always falls apart by the time shorter-range guidance comes into play. No matter how good things look in the atmosphere.

I've had a feeling for awhile now that once our region finally gets a good old-fashioned snow storm, it will be from a system that gradually builds enthusiasm during the final few days leading up to it. Who knows, maybe this is it.

[sroc4]

Fantastic discussion everyone. Really educational. Happy to see some activity on the board, things certainly have been bleak.

From a purely non-scientific point of view, I'll say this: I am perfectly content (perhaps even pleased) that models are not throwing out consensus 'bullseye' target hits for our area at this juncture. For the past few years, it seems that every storm that gives us those big hits on LR guidance 5-7 days out almost always falls apart by the time shorter-range guidance comes into play. No matter how good things look in the atmosphere.

I've had a feeling for awhile now that once our region finally gets a good old-fashioned snow storm, it will be from a system that gradually builds enthusiasm during the final few days leading up to it. Who knows, maybe this is it.

Could not have said it better myself!

[heehaw453]

12Z Model round up for pre-Valentines Day storm consensus is CNE snow storm. I would give it until Friday/Saturday for better data fidelity before I start trusting anything. Like I said before these h5 long wave patterns in conjunction with MJO are favorable for snowfall in these parts. But like anything a discrete event is just that.

[Frank_Wx]

I've been mostly quiet as we approach a pretty active time period. I mentioned last week that we're looking at a pattern change to occur post FEB 10th. We're on our way there, and a nice snowstorm may come with it. This is made possible by an active MJO wave that will be propagating through phases 7&8 which enables an anomalous EPO ridge to form. This ridge dislodges the northern jet further south, and gives us the opportunity - FINALLY - to see northern and southern stream interaction. This has been missing pretty much all winter.

The bonus feature of the long range will be the Stratosphere. As of today, models continue to show a very robust SSWE happening around mid-February. We'll see if that comes to fruition but it's looking good. However, let's not get ahead of ourselves! We have a storm to track. Aka the pre-VDay storm.

The latest EURO did not have the phase. It is all southern stream driven (like all our storms this year). You're probably wondering, wait, you just told us the development of a -EPO should allow for more northern and southern stream phasing. While in theory this is true, the issue I'm seeing with this specific event is that we lose the PNA ridge, which ends up throwing off the rest of the 500mb set-up upstream. There is a very pesky short wave that tries to crash into the PAC NW around the 12th. This impacts our storm on the east coast. Couple that with the 50/50 Low position Scott talked about, there are a couple of things working against keeping our storm track to our S&E.

However, these types of things can change once they are better sampled. We definitely can't declare this event "dead" quite yet. Let's see where we stand come Saturday. It really won't take much. We really just need a better 50/50 position and better heights out west.

[Irish]

Sorry, I just see it being too warm for the 12th-13th storm, likely mostly rain. After that we have more promise.

[heehaw453]

Last two GFS runs 00Z/06Z based on teleconnection/pattern is what I was thinking for this storm. Nothing has changed with the LW pattern only s/w interaction on Op models is what varies. The linking of n/s with Atlantic trough is going to be the key and that is supported by NAO/MJO you name it.

We shall see. Can't post graphics travelling...

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