Currently monitoring guidance for March late 3rd through the 4th for the next ( beyond the 28th) significant event

[Typhoon Tip]

Alright ... let's try a different tact this go around.

There is an important signal for the dates in the title, one that I would characterize as a medium impact for now, with both higher and lower correction potential.

Firstly, I realize the villagers are bit edgy if not incensed by the debacle that's gone on in the models, wrt the 28th system. I mean I get it. Unfortunately, nature is not going to wait for you to get over it. The language contained is not intended to sell cinema here.  It's should be treated as an early awareness, outline some observations for consideration regarding the 3rd/4th event.  Technically being inside of 7 days ... (5.5 or so days 18z, and this is in shotgun sites of our region ...), this is not an atypical range to preliminary a threat assessment.  That is what this is for. It is important to compartmentalize these recent disappointments as being unrelated to this prospect - because simply put ... they are unrelated to this prospect. I will be happy to come in here and add the operative adjectives should this evolve in a clear and obvious d-drip direction..

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Basic synopsis:  A deeper more expansive full latitude trough than has been observed in recent weeks if not months, appears slated to be ejected out of the semi permanent -PNA nadir over the SW... resulting ultimately in a fast moving QPF loaded Miller A type low genesis and track that brings it to our doorstep by the end of the 3rd.   It is lifting N out of the Arklotext region, which climatologically that's brought flooding problems in springs, owing to proximity to warm inflow/Gulf of Mexico moisture source, resulting in an enormous PWAT transport. We have ample cold on the N side of this particular low. Presently modeled in both the Euro and GFS operational version ... a cryo sufficiently cold air mass is in place across PA/NY NE England, back built by +PP in Ontario, already as this system is modeled to approach.   The cold side of risks a hefty amount of liq equiv in S/IP/ICE over perhaps a 12 to 18 hour period.  

Models: You are all aware of the 00z, 06z, 12z, and this recent 18z blends of the GFS ... but for the sake of discussion: monster in that particular guidance source.  Negatively tilted with over a 100kts of massively loaded jet transport. The exit/lateral/entry regions of this thing are extraordinary, even as it is being force by the antecedent and on-going -PNA footprint, to open up a dish pan trough structure when it cross through - again...as GFS is arranging things.  This is the most intense version of this system I can find, moving the low track over central LI to SE Ma ~  targeting deep interior for goodly dose of IP/ZR and snow W_N

The Euro made a pretty significant correction N... having about half to 3/4 of the GFS amplitude, targeting DC to NJ for a significant snow event. 

Perhaps the most use/telling are the ensemble means... The GEFs seem to parrot the operational version, having an impressively large deep solution that varied from SE Ma to the Benchmark over the last several cycles.  The EPS has made significant attempt toward more structure, as has the GEPs...  Perhaps someone can post those images ? 

All these are improving over cycles, with the EPS and GEPs making a more convincing lurch today.  They also have an interestingly varied spread in intensity, with some of them getting rather exotic - this I feel owes to the incredible diabatic inject this system has as a ( really ...) early spring, deeper latitude origin, riding N into a cold antecedent/seasonal latency in place in our region.  Hence the high ceiling potential. The "super blend" of these is almost a perfect scenario ... but that's likely just a present artifact of noise.  

Caveats emptors and the lower ceiling potential: 

1 .. the -PNA footprint is raging through next week, and March 4.  System ejected out of the west will need to supply  ( most likely...) there own mechanical power to overcome being lift over the negative (NVA) aspect of the SE ridge.   

2 ..In reality, I suspect some de-magnification shit will occur.   ...I don't believe the GFS is necessarily right with 20" in Albany and 3" of sleet and ZR from Kevin to myself... But, the blend of the GEFS/EPS/GEPs is trending to a much, much more deeper full troposphere ejection through the W.  As comparison, that's a much different animal compared to the over-sell that took place with the 28th and is also the biggest mass modality we've seen perhaps since Dec. 

[ORH_wxman]

Really nice outline John…thanks for the start on this thread. 
 

Im going to ask people to keep this thread cleaner than the last one. Keep the discussion on topic. There’s going to be highs and lows on the model guidance, but stick to the meteorology. We have a banter thread too if peeps need to sound off (and a panic thread too). 

[FXWX]

10 minutes ago, ORH_wxman said:

Really nice outline John…thanks for the start on this thread. 
 

Im going to ask people to keep this thread cleaner than the last one. Keep the discussion on topic. There’s going to be highs and lows on the model guidance, but stick to the meteorology. We have a banter thread too if peeps need to sound off (and a panic thread too). 

Good move Will...

[ineedsnow]

18z EPS  took a big shift towards the GFS some really strong members in there

[MJO812]

1 minute ago, ineedsnow said:

18z EPS  took a big shift towards the GFS some really strong members in there

There is a limit to how far north this can go

[Typhoon Tip]

41 minutes ago, ineedsnow said:

18z EPS  took a big shift towards the GFS some really strong members in there

Seeing a repeating theme of very deep pressures spread around odd locations considering the synoptics … Again, I suspect as is/was the case in the GEFs, this may be owing to the very large latent heat ingest this system had access to when it emerges out of the Arklotex region. 

[Chris12WX]

1 hour ago, MJO812 said:

There is a limit to how far north this can go

Please explain.

[MJO812]

Just now, Chris12WX said:

Please explain.

Explain the block that we have in place ? Look at what's going on with Mondays storm.

[ineedsnow]

0z GFS over ct

[ineedsnow]

0z CMC  much further north compared to 12z  just grazes SNE 

[Chris12WX]

6 minutes ago, MJO812 said:

Explain the block that we have in place ? Look at what's going on with Mondays storm.

No. Are you suggesting the GFS is the western goal post? Or that the GFS is wrong and the Euro is correct? Or that a blend of the two is more accurate? 

[SnoSki14]

16 minutes ago, MJO812 said:

Explain the block that we have in place ? Look at what's going on with Mondays storm.

GFS is trending towards more confluence for the 3/4. If that continues then the storm will have to transfer to the coast like CMC shows.

Unless the storm phases in that case you're looking at a powerful inland runner. Either way it should be interesting 

We'll know more after the 28th storm passes. 

[George001]

Good start to the 0z suite, big shift north.

[jbenedet]

I don’t like this one for snow chances for 90% of us. A 975 mb low will laugh at confluence that is not accompanied by surface cold anomalies.

Looks quite warm out ahead. All cold behind—it will want to gain significant latitude.
 

First guess is I think VT and upstate NY in good spot, as are far interior of NH and Maine. Mainly rain elsewhere.

 

[SnoSki14]

12 minutes ago, jbenedet said:

I don’t like this one for snow chances for 90% of us. A 975 mb low will laugh at confluence that is not accompanied by surface cold anomalies.

Looks quite warm out ahead. All cold behind—it will want to gain significant latitude.
 

First guess is I think VT and upstate NY in good spot, as are far interior of NH and Maine. Mainly rain elsewhere.

 

A system will rapidly deamplify and transfer to the coast under strong confluence.

The setup with Greenland blocking and a 50/50 underneath suggests there will be some confluence in place.

The question becomes how strong will it be. 

As of now the GFS solution is an outlier however if models trend towards a weaker 50/50 then a cutter will play out.

In that case you'd wanna be west as even VT/NH would flip to rain. 

It's too early to tell exactly what will happen 

[George001]

13 minutes ago, SnoSki14 said:

A system will rapidly deamplify and transfer to the coast under strong confluence.

The setup with Greenland blocking and a 50/50 underneath suggests there will be some confluence in place.

The question becomes how strong will it be. 

As of now the GFS solution is an outlier however if models trend towards a weaker 50/50 then a cutter will play out.

In that case you'd wanna be west as even VT/NH would flip to rain. 

It's too early to tell exactly what will happen 

The Pope is right. That weak blocking isn’t going to be enough to stop a 975mb low from gaining latitude. Stronger storms move poleward, that’s what they do. The gfs isn’t really an outlier, the EPS made a big shift north the past couple of cycles and so has the Canadian. And when you take into account that guidance underestimates the WAR at this range, it can be argued that there is room for this to trend even more north. I guess it’s possible it goes back south, but I’m really liking this setup. Hopefully the Euro makes a bump north at 0z.

[40/70 Benchmark]

EURO is LBSW graze.

[SnoSki14]

1 hour ago, George001 said:

The Pope is right. That weak blocking isn’t going to be enough to stop a 975mb low from gaining latitude. Stronger storms move poleward, that’s what they do. The gfs isn’t really an outlier, the EPS made a big shift north the past couple of cycles and so has the Canadian. And when you take into account that guidance underestimates the WAR at this range, it can be argued that there is room for this to trend even more north. I guess it’s possible it goes back south, but I’m really liking this setup. Hopefully the Euro makes a bump north at 0z.

And Euro affirms that the GFS is an outlier atm.

And like I said if the weaker confluence scenario is true then yes the GFS will be right but that's not a foregone conclusion. 

How's your Boston blizzard working out? 

[40/70 Benchmark]

The 00z OP EURO is a blue print for one good nuclear melt before ride off into the sunset for the season.

[40/70 Benchmark]

That PV lobe N of ME is going to be a big problem for someone if EURO is more right....gonna be a sharp cut off with this one like Jan 2016 and Jan 96 (not saying its of that caliber, just prominent examples that people will remember). The N edge of the heavy snow band will be nuclear assuming this doesn't get shredded.

The GFS starts phasing the lobe in over PA and NYS, but the EURO has it out ahead more to the NE so that it shunts the system and doesn't phase until the maritimes. Gonna be an interesting model war....a compromise between the two could be very nice if that PV decided to give that southern wave road head near the cape.

[40/70 Benchmark]

Looks as though there are several 00z EPS members that have that middle ground phasing that annihilates sne.

[The 4 Seasons]

EPS 3-run trend, not including off-hour, is shrinking the spread quite significantly and converging on a coastal track that would be favorable for much of SNE. 

GEPS/EPS seem in pretty good agreement right now with GEFS being the far NW outlier, takes the mean Low right over CT. We're still pretty far out in time ~132hrs but the >6" probs are pretty high for this time lead for a good chunk of SNE...which also have dramatically increased since last run.

[Ginx snewx]

1 hour ago, The 4 Seasons said:

EPS 3-run trend, not including off-hour, is shrinking the spread quite significantly and converging on a coastal track that would be favorable for much of SNE. 

GEPS/EPS seem in pretty good agreement right now with GEFS being the far NW outlier, takes the mean Low right over CT. We're still pretty far out in time ~132hrs but the >6" probs are pretty high for this time lead for a good chunk of SNE...which also have dramatically increased since last run.

Good post to take Ray off the Tobin. Dude is teetering 

[jbenedet]

This one will be fun to watch because it’s going to be in absolute beast mode by the time it hits Texas. I think even the GFS guidance is conservative with the early intensity of the surface reflection.

MJO firmly in phase 7 with the way the pacific has been this year?! 

We’re looking at a system that will strongly influence the downstream upper air environment —WARM. So you’re going to need very well timed blocking or staunch blocking. We don’t have the latter. But with the -NAO chances are we could score the former.

For now, my forecast bias is still strongly tilted towards a warm outcome given the way the Pacific floodgates are open and we don’t have antecedent cold over the northeast US or southeast Canada.

[40/70 Benchmark]

1 hour ago, Ginx snewx said:

Good post to take Ray off the Tobin. Dude is teetering 

Well, to be fair, it's easier to feel good about things in CT because you have lesser shot of being porked....you are guaranteed to do well Tuesday, then have less shot of being screwed Friday. I am done for on Tuesday and there is a chance that PV lobe by Maine screws me Friday.

[40/70 Benchmark]

3 hours ago, The 4 Seasons said:

EPS 3-run trend, not including off-hour, is shrinking the spread quite significantly and converging on a coastal track that would be favorable for much of SNE. 

GEPS/EPS seem in pretty good agreement right now with GEFS being the far NW outlier, takes the mean Low right over CT. We're still pretty far out in time ~132hrs but the >6" probs are pretty high for this time lead for a good chunk of SNE...which also have dramatically increased since last run.

 

4 minutes ago, 40/70 Benchmark said:

Well, to be fair, it's easier to feel good about things in CT because you have lesser shot of being porked....you are guaranteed to do well Tuesday, then have less shot of being screwed Friday. I am done for on Tuesday and there is a chance that PV lobe by maine screws me Friday.

What I am saying is evident in the EPS that is posted.

[40/70 Benchmark]

If that s stream doesn't phase with the PV lobe, then confluence will stop it at some point if it's close enough....then of course, if it does phase, then we want the timing to be right or else you get a GFS solution.

Lots to work out, but there is less risk in CT IMO.

[mahk_webstah]

49 minutes ago, jbenedet said:

This one will be fun to watch because it’s going to be in absolute beast mode by the time it hits Texas. I think even the GFS guidance is conservative with the early intensity of the surface reflection.

MJO firmly in phase 7 with the way the pacific has been this year?! 

We’re looking at a system that will strongly influence the downstream upper air environment —WARM. So you’re going to need very well timed blocking or staunch blocking. We don’t have the latter. But with the -NAO chances are we could score the former.

For now, my forecast bias is still strongly tilted towards a warm outcome given the way the Pacific floodgates are open and we don’t have antecedent cold over the northeast US or southeast Canada.

GYX seems to agree.  Has it both rain and snow up here.  A significant snow is still on the table, but it gets iffy in and south of the foothills.  The way things have been this year, and this last several days suggests that we have a ways to go, and that the evolution of the next system will probably tell us something about 4th.  For up here, we dont' need much of a nudge to have a snowstorm, but dicier for SNE.  Also those GEFS and EPS ensemble probs for 6+ snow were quite far south last night.

[qg_omega]

50 minutes ago, jbenedet said:

This one will be fun to watch because it’s going to be in absolute beast mode by the time it hits Texas. I think even the GFS guidance is conservative with the early intensity of the surface reflection.

MJO firmly in phase 7 with the way the pacific has been this year?! 

We’re looking at a system that will strongly influence the downstream upper air environment —WARM. So you’re going to need very well timed blocking or staunch blocking. We don’t have the latter. But with the -NAO chances are we could score the former.

For now, my forecast bias is still strongly tilted towards a warm outcome given the way the Pacific floodgates are open and we don’t have antecedent cold over the northeast US or southeast Canada.

Disagree, highly doubt this phases with the PV.  Destructive interference is much more likely

[40/70 Benchmark]

1 minute ago, qg_omega said:

Disagree, highly doubt this phases with the PV.  Destructive interference is much more likely

Well, it will likely phase at some point, but at what point...even EURO eventually phases it in Maritimes..but not before having it shredded.