01/22/16-01/23/16 Update #1 - Historic Storm Possible

SNOW MAN wrote:

Frank_Wx wrote:Here is 06z GFS snowman. Right now there are two evolutions shown on the models. Both evolutions give the area snow, so it is win win for us. But not for inland areas into PA. 

Thanks Frank.

Yep confirms my thinking. Even SNE does great in this run. Wow what a map!!! It shows 2ft+ for most of NJ, and the scary part is that's without ratios!!!

Each map shows something different for the coast does their look to be mixing issues

WOW!!! Frank! The euro, and GFS and Canadian ALL showing 18"+. When have you ever seen that. Too bad we are still 4 days out.

Let's not forget about the NAVGEM & JMA showing the storm too.

When u wake up to 6 pages from a thread frank started last night it's big where's sroc

Snowfall wrote:When u wake up to 6 pages  from a thread frank started last night  it's big where's sroc

Got that right lol

Frank, your map has a timestamp of jan 28, is that a separate storm?

This reminds of 92' for coastal no. Except with more snow

If this historic event should happen- and my confidence level is starting to build one has to wonder with such a dynamic storm, what the high resolution short range models might find in those CCB bands. The atlantic waters are very warm which could cause quite explosive results with thundersnow. I would not be surprised to see 3ft lollipop amounts in and around the area if this storm lives up to its full potential.

And imo if this storm comes through with the warm Atlantic I wouldn't be surprised for no coast to get 2ft plus like boxing day

Looking at the Euro surface maps it appears there be one of two things happening here.  Either convective feedback or the LP is becoming occluded.  

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Notice how At hrs 138-144 there is a second center N and east of the main center of LP.  The bulk of the Moisture shield is actually around the LP center further to the NE rather than the one just off the coast.  I believe there is a reason for this and I will explain.

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If this is a convective feedback problem than it means the model is having trouble with where to place the center of the LP and everything looks spread out.  As we move closer this should correct and everything should consolidate into one large precip shield, and the expansion of higher snow totals back NW to interior areas should occur.

However, I believe this is actually the latter, occlusion of the main Low.  When I look at the 500mb charts I see that the main area of LP just off the Delmarva at hr 144 it is nearly beneath it.  This in essence occludes the surface LP AKA caps it off over top.  What I mean by that is the divergence(air moving away from itself) over the top of the surface LP needed to strengthen it is no more.  The reason being is that now by hrs 138- 144 the upper level LP, with counterclockwise air rushing towards its center, is directly over top of the surface LP center, which also has counter clockwise winds rushing towards its center.  

As the air rushing into the center of any LP collides with itself it is going to either move up or down right?  At the surface there is nowhere for this colliding air to go but up because of the ground which strengthens vertical upward motion deepening the LP and enhancing convection and precip.  However because an upper level LP also has air crashing into itself at the center it does not have the ground to limit which direction that air moves. So while some air will move up, you will also get air to move down causing sinking air at its center.  If there is a surface LP benath this sinking air it will essentially limit the rising air of the surface LP effectively "occluding it, or capping it off.  

The best analogy for this is your fireplace.  If the flue of your fireplace is wide open then the warm air from the fire(surface LP) is allowed to rise rapidly and exit the chimney maximally.  If you close the flue partially or completely(surface LP slides under the ULL) you limit the rising warm air and the flames become dampened until it essentially burns(snows) itself out.  

Here you can see the surface LP is sitting right under the ULL by hr 144

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The reason we get enhanced precip to the NE and a second center of LP is that we have two jet streaks at 300mb.  Now while the main area of LP is being dampened by upper level convergence, ULL sitting on top of it, that second area of LP and enhanced precip is because of enhanced upper level divergence.  The L front quadrant and the R rear quadrants of a jet streak as a general rule will lead to enhanced upper level divergence in these locations(small black circle in image below).  If you have divergence aloft then you can only infer that the air to replace it comes from underneath it at the surface.  Rising air as we all know lowers pressures and enhances convection and precip.


This is why I think we see what we see on the Euro.  I see it on the other models as well but believe the Euro is handling this the best at the moment.  We will have to see how this trends going forward and the timing of the occlusion of the main low.  This may be a limiting factor in just how far interior the expansion of the precip field can make it, leading to sharp cutoffs.

Snowfall wrote:When u wake up to 6 pages  from a thread frank started last night  it's big where's sroc

I have decided to remain relatively quite until Tuesday, mostly for superstitious reason, however, I did offer some analysis above. I still want to get to the Tuesday Wed time frame to go all in since our energy is not onshore yet. That said I am 90% on board with a major storm to affect the entire area with details yet to be determined.

Still worried about a southern trend with what the ECM showed last night even though it wad personally still a great run. Have to watch the details. Lots of time to trend from a '96 challenger to a wide right too late Nemo. (Different setup I know, better example would be early Feb 2010 where I got 7", DC got like 3 feet, Philly almost 2 feet and NYC barely anything.... As I said dont worry about cutting or warm air, we want this to close off and stallright off New Jersey to put us in the best banding. Not down by DE, not way out in the ocean. Literally just off of ACY tucked in between NJ and LI parked would slam the whole I95 corridor down to the coast.

rb924119 wrote:Nice post above, Sroc. Not trying to be an a$$, but there are a couple of small details that aren't quite right, but it does get the point across. Anyway, I'm totally with you in the sense of not getting hopes up. I do not like the southeast trend of the Euro Op and it's ensemble, and the new look they give to the western ridge. The GFS still looks like it will continue to correct northwest, based upon the ensemble clustering of 500 hPa spaghettis showing a sharper trough in relation the other ensemble mean and even the Op. Lastly, it would still appear that the Canadian ensemble doesn't know what it wants to do, and is a total mess haha Really don't want to see that western ridge begin to collapse, but unfortunately, I think we will still end up with a further southeast track. We shall see.

When looking at the low locations on the euro ens there is a very small number of LP well S of the mean. I believe this small cluster is skewing the mean a tad further south and east. The main cluster seems to be tucked up inside NW of the mean. We shall see how the next 48hrs shakes out.

00z EPS

Comparatively the 6z GEFS are similarly clustered, with less south of the mean.

rb924119 wrote:

Quietace wrote:Comparatively the 6z GEFS are similarly clustered, with less south of the mean.

Yup, which is why I expect the mean to continue to correct northwest in successive runs. 00z (top) versus 06z (bottom):





There's a good portion that are inside the mean and Op, which is a GREAT sign, and honestly, what I hope the Euro corrects to lol

The Para Euro has been NW of the OP since it has shown the system, yet the 0z data is not available on WXbell yet so I cant compare yet.

FWIW, TWC just had their report and hinting at the "B" word saying a stay at home snow storm sat, said a foot in DC maybe 6 inches north of there (what are they looking at?), and the winds will be high and come in off ocean warm temps to just around freezing so its not go be really cold? What are they looking at and btw they were talk bout euro. But needless to say media is chirping i give it another day or two b4 the panic sets in. If you all know frankie from nova scotia on youtube (he is autitistic) I love to watch his videos, you wanna talk about weather excitement! I am trying so hard to temper and sorry for my all out excitement pour out lat night lets just say I was "out, having a bit too much fun lol" and checking on my phone.

Sorry OT but if anyone saw ttwc within the past hr or seen news that 14 car accident that has the bronx river parkway shutdown in yonkers is the exit near my mother in law. Just crazy highwway will be closed until tuesday!

rb924119 wrote:

jmanley32 wrote:FWIW, TWC just had their report and hinting at the "B" word saying a stay at home snow storm sat, said a foot in DC maybe 6 inches north of there (what are they looking at?), and the winds will be high and come in off ocean warm temps to just around freezing so its not go be really cold?  What are they looking at and btw they were talk bout euro.  But needless to say media is chirping i give it another day or two b4 the panic sets in.  If you all know frankie from nova scotia on youtube (he is autitistic) I love to watch his videos, you wanna talk about weather excitement!  I am trying so hard to temper and sorry for my all out excitement pour out lat night lets just say I was "out, having a bit too much fun lol" and checking on my phone.

Sorry OT but if anyone saw ttwc within the past hr or seen news that 14 car accident that has the bronx river parkway shutdown in yonkers is the exit near my mother in law.  Just crazy highwway will be closed until tuesday!

Jman, just for you, here's the extended GFS MOS data for NYC, which is a tabled model output for the weather station's location. The numbers I have highlighted are the progged sustained wind speeds in knots. Would this quench your thirst for wind? haha

Jeeze is that sustained? 44mph (or is it kts) for a period of the event.  Ummm ya lol