December 1st-3rd 2019 Winter Storm Potential

Good morning all.  I figure Id start a thread regarding early next weeks potential because I wanted to lay out some of the key upper level features that will help set the stage for the possibility of wet, white, and mixed precip, but as usual the devil is in the details which wont come to light until late week most likely.    I dont want it to get lost in the other thread as we cont to discuss it.  Keep in mind this potential, and I stress potential, is still 6-7days out and several key features that will play an integral part have yet to even develop.  Timing, strength, and positioning of the these upper level features which will be dictated by the mid week system, will set us up for this possibility for the early next week system.  So when model watching this week keep this in mind....little detail shifts in the upper levels will lead to MUCH larger shifts in the details at the surface.  When have we ever seen the surface details of a system verify at this range?  Never!  

So again this thread will highlight the big picture only.   Here goes:


Within about 24 hours this is what the 500mb configuration will look like.  





What we have is a stout -NAO ridge over Greenland(blocking ridge), a -PNA(trough) along the west coast(WC), and a N Pacific ridge centered south of Alaska, and west of the WC of Canada.  The mid week system, that will bring the gusty winds for Thanksgiving, will form as a result of a piece of the energy from the WC trough spinning up into an upper level low (ULL).  This ULL will cut and track well up into the GL before it takes a brief turn S&E and passes off the NE coast line.  This track of course leads to our area in the warm sector of the surface low and therefore precip is mostly wet; perhpaps some sloppy mix and wet snow changes over well to the N&W.  Look again above.  Its because of the ridge axis being centered where it is that allows the ULL to cut as far north and west as it does; however, its the -NAO ridge to our NE that actually prevents it from tracking even further N.  The N Atlantic blocking actually is what shifts it track back to the S&E.  Hopefully the giff above is woking so you can follow the mid week ULL and see its track as it exits the NE coast.  NOTE: when an ULL tracks to our N its almost a lock that most of our area is on the warm side of a system.  This will be a key point when we discuss the early week potential below.  

Let's shift gears now.  Below is the 500mb configuration by late Wed eve.  As you can see the ULL is in the upper GL and is about to be shunted a little S&E from here.  

But pay attention to how the Ridge trough configuration is developing out west.  This configuration is termed a Rex Block where you have 500mb HP Ridge north of 500mb LP trough to the south(Ridge over Trough) along the west coast.  Notice now that the N Pac ridge, which was S of Alaska over open water is now shifting east; nosing into the WC of Canada.  This is vital as you will see.     



As you can see below by 06z Sat(about 2am) the rex block is really established and the ridging continues to build east through Canada.  All the while our mid week ULL has taken up position at the 50N lat 50W Long (aka 50/50 low) position which in turn deepens and feeds back on the -NAO ridge to its north leading to its enhancement as we cont through Sat.   This leads to cold canadian air filtering in behind the mid week system.




Below now is valid for 21z (5pm Sat eve).  The next piece of energy has broken off from the WC trough and ejected N&E; however, this is as far north as it gets on this run due to the rex block over top to the north.  As you saw in the mid week storm set up above the higher heights were not there over Canada so the ULL was able to traverse N&E unimpeded until it encountered the N Atlantic blocking (-NAO) where it was shunted S&E.  




In this set up however the ULL is shunted S&E and takes a track through the Ohio valley and exits the EC somewhere near central to south NJ on this run.  Now notice a few things in the loop above and the static image below.  




As the ULL approached the EC the -NAO blocks is breaking down, as is the Rex block.  The EPO region is becoming strongly +.  The timing of this is important.

The take home:

1) We have to see a track that takes the ULL south of Long Island in order to max the white chances for any of us.  

2) If the Rex block breaks down too quickly then it will allow the ULL to gain more latitude over the central CONUS before turning ESE and thus exiting the EC further N.  bringing us closer to the warm sector.  

3) If the -NAO block breaks down too quickly the same problem as point 2 above can happen.  

4) If both the rex block and NAO block break down too quickly then it becomes a full on cutter and no one is white; we torch when the precip arrives (least likely scenario but possible)


Like I said in my summary of the overall pattern last week, I believe a resistance is in the air in the form of a very incoherent MJO signal.  Despite the fact that the forcast graphs have it in the COD  there is high variability in what is happening dayater day let alone in 6-7 days from now.  Of course the N&W peeps have the best chance to cash in here, andd I do believe N&W of I-95 sees accumulation.  That said Im not totally out for the coast either.  The blocking is there to allow it to happen, but the details of how it all plays out is still in question for me.   Overall the GFS and Euro (all euro maps used above) are very similar in the big picture set up I described above with the subtle differences in where the ULL exits the coast and as it does so the GFS has a more neutral to neg tilt where as the Euro is still a more progressive or positive tilt.  If you look at the surface maps between the two you'll see the GFS tries to form a deformation band on the NW side of the surface LP associated with the neg tilt to the trough where as the precip shield is more disorganized and scattered on the euro.  As a result a difference in snow fall totals and total QPF exists regardless of where it falls.  GFS much higher overall vs the lower totals on the euro.  These are the details for which we should not be worried about until late in the week.  

WE TRACK!!!  

Well quite the run on the 12z GFS

I think chances of getting at least an inch for most folks are going up.  Front end WAA if we miss out on the coastal.  I understand it's at least 5 days out, but this is legit tracking at least.  

This kind of image gets me optimistic and seeing a lot of model guidance trend towards coastal in this general area.  We will have to play the model game for a few more days at least, so expect the usual bad days before we know.

Yeah that storm looks like it could be pretty strong which could also create more cold if I'm correct. I have a feeling even the coast will do well even if relative to this time of year. Or maybe we all get the g word!!

LOL! 18Z GFS storm sits off the NJ coast for a day caught in the block. That kind of solution would yield monster snow totals.

heehaw453 wrote:LOL!  18Z GFS storm sits off the NJ coast for a day caught in the block.  That kind of solution would yield monster snow totals.  

The HH 18Z run.
But not out of the realm with a NAO AND A 50/50 BLOCK. last night Oz had is actually transcend ESE then NW then NE. We have seen some crazy trackers with our storm due to this block which has been underestimated all year long like to WAR.
Time will tell but as Scott said ....WE TRACK!!

Getting interesting now for the LHV.NWS now has me all snow for the event.Looks like the first accumulating snow is on the way.

amugs wrote:

heehaw453 wrote:LOL!  18Z GFS storm sits off the NJ coast for a day caught in the block.  That kind of solution would yield monster snow totals.  

The HH 18Z run.
But not out of the realm with a NAO AND A 50/50 BLOCK. last night Oz had is actually transcend ESE then NW then NE. We have seen some crazy trackers with our storm due to this block which has been underestimated all year long like to WAR.
Time will tell but as Scott said ....WE TRACK!!

Bring it home Doc and Mugsy! It would be nice to see a significant early December snowstorm.

SoulSingMG wrote:OOF.

yeah, big storm would be a G.... for inland and us coasties may see a few inches, need to get it colder somehow or system slightly more offshore. 850 winds would also make this a B word.

jmanley32 wrote:

SoulSingMG wrote:OOF.

yeah, big storm would be a G.... for inland and us coasties may see a few inches, need to get it colder somehow or system slightly more offshore.  850 winds would also make this a B word.

Meh. Until the Euro comes on board I'm remaining skeptical.

GFS thermals are always wrong give me low that bombs off the coast with a block screams dynamics and big snow remember sometimes you smell the rain and get big snows my coastal peeps should now this

What did the Euro show snow wise for the area? I can't tell a thing from 24 hours panels on tidbits.

Personally, I would not set high expectations for this system, folks. I don’t think this system will be much of a winter event based on what I’m seeing, but hey, I’ll still track it!

GEFS are in a prime spot

rb924119 wrote:Personally, I would not set high expectations for this system, folks. I don’t think this system will be much of a winter event based on what I’m seeing, but hey, I’ll still track it!

ok so last time u were wrong so sorry but hope that happens again this time lol. Ur still smart but I oh so want you to be wrong.

jmanley32 wrote:

rb924119 wrote:Personally, I would not set high expectations for this system, folks. I don’t think this system will be much of a winter event based on what I’m seeing, but hey, I’ll still track it!

ok so last time u were wrong so sorry but hope that happens again this time lol. Ur still smart but I oh so want you to be wrong.

How was I wrong last time? Lol there were “surprise” snow totals all the way down into Putnam county and into Connecticut. Even NW NJ had some snow out of that. I was never supposed to make it into the city. That said, I never did issue an official forecast so I guess it’s a mute point. But all that said, part of me hopes I’m wrong too, and no hard feelings hahaha :p

rb924119 wrote:Personally, I would not set high expectations for this system, folks. I don’t think this system will be much of a winter event based on what I’m seeing, but hey, I’ll still track it!

While I think I know where your at, care to elaborate a little?

We are 5/6 days away nothing etched in stone upper air pattern looks great surface we look at as we get closer

sroc4 wrote:

rb924119 wrote:Personally, I would not set high expectations for this system, folks. I don’t think this system will be much of a winter event based on what I’m seeing, but hey, I’ll still track it!

While I think I know where your at, care to elaborate a little?  

Doing this from mobile for a third time is annoying, but because I love you guys, I’ll forward the cliff notes version

The below is a post from Armando’s board in response to if my reason why is because it will be too warm:

“Yes, but that’s only part of it. The trajectory of the system as well as how I expect this trajectory to evolve as a result of the ambient hemispheric synoptics are the others. I have posted more technical discussion over on 33 if you’re there, but basically the evolution of this system is not one that is auspicious for significant winter weather for our area in my opinion. Storms that come from the west are almost always overmodeled in their precipitation fields, only to seemingly disappear as lead time decreases. This is supported when you look at mid-level streamflow, which depicts your “deep” moisture source to be almost exclusively from the Pacific. This then gets downsloped over the Rockies with very little additional moisture flux from the Gulf and Atlantic. Secondarily, this system reaches maturity over the Upper Midwest, and then slowly decays as it continues east-southeastward. So, while it presents itself as a “classic bowling ball” low, in reality, almost all of the dynamics associated with a more classic deepening/maturing cyclone through the column, one that actively is closing off south and/or east of our area, will be non-existent. The mid-levels are not organized enough to support this, and the window of *temporary* reorganization is very small given the progressive nature of the system. Third, when you look at the state of the ambient synoptic atmosphere/ocean couplet, it supports less of a suppressing effect on this system, which makes me think that we end up seeing it pass directly over or even slightly north of our area. This does two things: 1. Prevents us from being in any favorable location for any remaining dynamics to assist in precipitation rates/thermal profiles, as we will get dry slotted. 2. Allow for the stale Pacific air that this system is bringing with it to dominate, as the warm advection out ahead of this would be not be countered. This leads me to additional points that because this system starts so far north/west, the effects of the frontrunning warm advection will be enhanced for us, and without any fresh injection of cold air from a northern stream system, we have no real way to mitigate it in-situ. Secondly, once you get through the initial warm advection surge, conditions will be generally unsettled with showery type precipitation and generally “milder” conditions as the mid- and low-level lows pass overhead.”

I think today’s 12z EURO Op was pretty close in its depiction of sensible effects at the surface, though I fear it could even get a little worse than that by the time it’s over. If you want me to diagnose further, though, let me know, but I think that you can synthesize the details I left out regarding the synoptic hemispheric/oceanic alignments haha

You actually mentioned some of my worries in your excellent discussion

rb924119 wrote:

jmanley32 wrote:

rb924119 wrote:Personally, I would not set high expectations for this system, folks. I don’t think this system will be much of a winter event based on what I’m seeing, but hey, I’ll still track it!

ok so last time u were wrong so sorry but hope that happens again this time lol. Ur still smart but I oh so want you to be wrong.

How was I wrong last time? Lol there were “surprise” snow totals all the way down into Putnam county and into Connecticut. Even NW NJ had some snow out of that. I was never supposed to make it into the city. That said, I never did issue an official forecast so I guess it’s a mute point. But all that said, part of me hopes I’m wrong too, and no hard feelings hahaha :p

Wasnt there a system where you said you had egg on your face? I could sworn I saw that which also made me laugh cuz this is not a exact science. And yes you were partially right, no one can get it exact, if they did that would be amazing.

rb924119 wrote:

sroc4 wrote:

rb924119 wrote:Personally, I would not set high expectations for this system, folks. I don’t think this system will be much of a winter event based on what I’m seeing, but hey, I’ll still track it!

While I think I know where your at, care to elaborate a little?  

Doing this from mobile for a third time is annoying, but because I love you guys, I’ll forward the cliff notes version

The below is a post from Armando’s board in response to if my reason why is because it will be too warm:

“Yes, but that’s only part of it. The trajectory of the system as well as how I expect this trajectory to evolve as a result of the ambient hemispheric synoptics are the others. I have posted more technical discussion over on 33 if you’re there, but basically the evolution of this system is not one that is auspicious for significant winter weather for our area in my opinion. Storms that come from the west are almost always overmodeled in their precipitation fields, only to seemingly disappear as lead time decreases. This is supported when you look at mid-level streamflow, which depicts your “deep” moisture source to be almost exclusively from the Pacific. This then gets downsloped over the Rockies with very little additional moisture flux from the Gulf and Atlantic. Secondarily, this system reaches maturity over the Upper Midwest, and then slowly decays as it continues east-southeastward. So, while it presents itself as a “classic bowling ball” low, in reality, almost all of the dynamics associated with a more classic deepening/maturing cyclone through the column, one that actively is closing off south and/or east of our area, will be non-existent. The mid-levels are not organized enough to support this, and the window of *temporary* reorganization is very small given the progressive nature of the system. Third, when you look at the state of the ambient synoptic atmosphere/ocean couplet, it supports less of a suppressing effect on this system, which makes me think that we end up seeing it pass directly over or even slightly north of our area. This does two things: 1. Prevents us from being in any favorable location for any remaining dynamics to assist in precipitation rates/thermal profiles, as we will get dry slotted. 2. Allow for the stale Pacific air that this system is bringing with it to dominate, as the warm advection out ahead of this would be not be countered. This leads me to additional points that because this system starts so far north/west, the effects of the frontrunning warm advection will be enhanced for us, and without any fresh injection of cold air from a northern stream system, we have no real way to mitigate it in-situ. Secondly, once you get through the initial warm advection surge, conditions will be generally unsettled with showery type precipitation and generally “milder” conditions as the mid- and low-level lows pass overhead.”

I think today’s 12z EURO Op was pretty close in its depiction of sensible effects at the surface, though I fear it could even get a little worse than that by the time it’s over. If you want me to diagnose further, though, let me know, but I think that you can synthesize the details I left out regarding the synoptic hemispheric/oceanic alignments haha

So sorry oh mighty Ray. For I do not mean to trouble you. I know how difficult it can be to “copy and paste”, especially for a third time. I hope your not experiencing any pronounced carpal tunnel as a result. That said I appreciate the analysis.

sroc4 wrote:

rb924119 wrote:

sroc4 wrote:

rb924119 wrote:Personally, I would not set high expectations for this system, folks. I don’t think this system will be much of a winter event based on what I’m seeing, but hey, I’ll still track it!

While I think I know where your at, care to elaborate a little?  

Doing this from mobile for a third time is annoying, but because I love you guys, I’ll forward the cliff notes version

The below is a post from Armando’s board in response to if my reason why is because it will be too warm:

“Yes, but that’s only part of it. The trajectory of the system as well as how I expect this trajectory to evolve as a result of the ambient hemispheric synoptics are the others. I have posted more technical discussion over on 33 if you’re there, but basically the evolution of this system is not one that is auspicious for significant winter weather for our area in my opinion. Storms that come from the west are almost always overmodeled in their precipitation fields, only to seemingly disappear as lead time decreases. This is supported when you look at mid-level streamflow, which depicts your “deep” moisture source to be almost exclusively from the Pacific. This then gets downsloped over the Rockies with very little additional moisture flux from the Gulf and Atlantic. Secondarily, this system reaches maturity over the Upper Midwest, and then slowly decays as it continues east-southeastward. So, while it presents itself as a “classic bowling ball” low, in reality, almost all of the dynamics associated with a more classic deepening/maturing cyclone through the column, one that actively is closing off south and/or east of our area, will be non-existent. The mid-levels are not organized enough to support this, and the window of *temporary* reorganization is very small given the progressive nature of the system. Third, when you look at the state of the ambient synoptic atmosphere/ocean couplet, it supports less of a suppressing effect on this system, which makes me think that we end up seeing it pass directly over or even slightly north of our area. This does two things: 1. Prevents us from being in any favorable location for any remaining dynamics to assist in precipitation rates/thermal profiles, as we will get dry slotted. 2. Allow for the stale Pacific air that this system is bringing with it to dominate, as the warm advection out ahead of this would be not be countered. This leads me to additional points that because this system starts so far north/west, the effects of the frontrunning warm advection will be enhanced for us, and without any fresh injection of cold air from a northern stream system, we have no real way to mitigate it in-situ. Secondly, once you get through the initial warm advection surge, conditions will be generally unsettled with showery type precipitation and generally “milder” conditions as the mid- and low-level lows pass overhead.”

I think today’s 12z EURO Op was pretty close in its depiction of sensible effects at the surface, though I fear it could even get a little worse than that by the time it’s over. If you want me to diagnose further, though, let me know, but I think that you can synthesize the details I left out regarding the synoptic hemispheric/oceanic alignments haha

So sorry oh mighty Ray. For I do not mean to trouble you. I know how difficult it can be to “copy and paste”, especially for a third time. I hope your not experiencing any pronounced carpal tunnel as a result. That said I appreciate the analysis.

My emoticons aren’t showing up!!! There was supposed to be winking faces in there, I swear!!! That wasn’t meant to be negatively snarky, rather, entertainingly snarky haha though I think you know me well enough to interpret it that way (I hope haha). I will say, though, my thumbs are getting a bit tired lmaooo

jmanley32 wrote:

rb924119 wrote:

jmanley32 wrote:

rb924119 wrote:Personally, I would not set high expectations for this system, folks. I don’t think this system will be much of a winter event based on what I’m seeing, but hey, I’ll still track it!

ok so last time u were wrong so sorry but hope that happens again this time lol. Ur still smart but I oh so want you to be wrong.

How was I wrong last time? Lol there were “surprise” snow totals all the way down into Putnam county and into Connecticut. Even NW NJ had some snow out of that. I was never supposed to make it into the city. That said, I never did issue an official forecast so I guess it’s a mute point. But all that said, part of me hopes I’m wrong too, and no hard feelings hahaha :p

Wasnt there a system where you said you had egg on your face? I could sworn I saw that which also made me laugh cuz this is not a exact science. And yes you were partially right, no one can get it exact, if they did that would be amazing.

Oo yeah, that was the first one! Definitely blew that one, I fully admit that lmao but my last one went pretty well, but again, it was more of just a broad statement that north and west of the main 95 corridor had to watch out for sneaky snow/light accumulations. Similar to the one I just posted tonight; no “official” forecast/map or anything like that.