Major Nor'easter snow storm (possible top 20) Noon Wednesday-Noon Thursday Dec 16-17, 2020

[tdp146]

4 minutes ago, jm1220 said:

I think where you’d really want to pay attention is 750-800 mb. I’ll have to look up where there may be soundings. 

These are the warmest panels from the Euro for 850 and 700. I think the short term models will be key for this. NAM will pick up on the warm layers over LI. 

[HeadInTheClouds]

9 minutes ago, NJwx85 said:

If you want to know where the cutoff is, you can pretty much just follow the dewpoints. The 10 degree dew point line is probably close to where the brick wall sets up.

Really? You might want to inform the models, most of them are giving significant totals 50 miles north of that line you drew. 

[Brian5671]

1 minute ago, HeadInTheClouds said:

Really? You might want to inform the models, most of them are giving significant totals 50 miles north of that line you drew. 

he's trying to make a general point, it's not verbatim.    

[jm1220]

1 minute ago, tdp146 said:

These are the warmest panels from the Euro for 850 and 700. I think the short term models will be key for this. NAM will pick up on the warm layers over LI. 

Euro has the same resolution as the Nam so it should pick up the same warm layers etc. 

[Blizzardo]

4 minutes ago, WarrenCtyWx said:

That seems a little bit too far south. That would put Rockland and Orange counties out of the game.

and its still 48 hours out...

[NJwx85]

3 minutes ago, HeadInTheClouds said:

Really? You might want to inform the models, most of them are giving significant totals 50 miles north of that line you drew. 

Yeah, significant totals. Nothing approaching 18" like what you will see close to I-80.

[HeadInTheClouds]

2 minutes ago, Brian5671 said:

he's trying to make a general point, it's not verbatim.    

I disagree with his point though. There is going to be significant snow north of westchester county. 

[Blizzardo]

1 minute ago, HeadInTheClouds said:

I disagree with his point though. There is going to be significant snow north of westchester county. 

thats your opinion... just like its his opinion...which is in line with my opinion...

 

 

[jm1220]

FWIW Upton going with snow/sleet mix for now in E Suffolk and 4-8” S Fork, 6-10” N Fork. West of there for now all snow and 8-12” in W Suffolk and west. Additional snow Thu morning which wasn’t added in yet. 

[HeadInTheClouds]

1 minute ago, NJwx85 said:

Yeah, significant totals. Nothing approaching 18" like what you will see close to I-80.

Sure. I think the sweet spot will be Eastern Penn-Northern Jersey-Rockland/Westchester on east. 10-12 inch totals well north of there though according to most guidance. I don't consider that a cutoff. 

[HeadInTheClouds]

2 minutes ago, Blizzardo said:

thats your opinion... just like its his opinion...which is in line with my opinion...

 

 

i didn't say he wasn't entitled to his opinion. 

[NJwx85]

7 minutes ago, HeadInTheClouds said:

Sure. I think the sweet spot will be Eastern Penn-Northern Jersey-Rockland/Westchester on east. 10-12 inch totals well north of there though according to most guidance. I don't consider that a cutoff. 

You're going to go from 12" to 2" over a very short distance and that's going to be close to the line I indicated. Keep in mind the dew points are based on the 12z Euro so you can use your model of choice. Nobody knows for sure where exactly the snow stops, but the model consensus is just North of I-84.

[HVSnowLover]

32 minutes ago, jfklganyc said:

I go up on the water out there and within the Long Island spectrum that’s true. But when you look at the bigger picture, the eastern North Shore only works for snow if  you have a good coastal setup as opposed to 15 miles North and West of the city line which can work in various marginal scenarios. 

 

The storm is a perfect example. If it isnt marginal, North Shore does great. But if it is marginal, you would rather be in White Plains than Huntington

Agree you need stronger dynamics on north shore of LI to flip to snow than White Plains even though parts of the North Shore are close to same latitude. But White Plains is more like 30 miles inland not 10-15

[White Gorilla]

19 minutes ago, NJwx85 said:

You're going to go from 12" to 2" over a very short distance and that's going to be close to the line I indicated. Keep in mind the dew points are based on the 12z Euro so you can use your model of choice. Nobody knows for sure where exactly the snow stops, but the model consensus is between I-84 and I-90.

Closer to I 90 than I 84 imo 

[Blizzardo]

Just now, NJwx85 said:

You're going to go from 12" to 2" over a very short distance and that's going to be close to the line I indicated. Keep in mind the dew points are based on the 12z Euro so you can use your model of choice. Nobody knows for sure where exactly the snow stops, but the model consensus is between I-84 and I-90.

Exactly!! And I said anything north of the state line could be in for a rude awakening. Nobody knows just how far north the big snow will get but I'll never bet against cold dry air!

[jm1220]

6 minutes ago, HVSnowLover said:

Agree you need stronger dynamics on north shore of LI to flip to snow than White Plains even though parts of the North Shore are close to same latitude. But White Plains is more like 30 miles inland not 10-15

The snow average for White Plains from what I know is something like high 30 inches annually while for me it’s a little less but not much, low 30s I think. In recent years this area really benefitted from the late developer Miller B events that Westchester might not have gotten as much from. But in I-95 rain snow line events it’s definitely better being in White Plains. 
 

White Plains is also higher in latitude. I’m at the Bronx/upper Manhattan latitude. 

[Blizzardo]

1 minute ago, Torch said:

Only 50% of the time. The other 50% coastal hugger.

No.. its still wins even with a hugger but its not in our area..

[CIK62]

NAM is wishy washy with the snow as it alternates Snow/Rain and ends up as just 6". (Cobb Method)      GFS is all Snow, but gives only 8" for several runs. (Cobb Method)[it had a 33" run 2 days ago]

The CMC and EURO  are about 15"(Kuchera)

[HeadInTheClouds]

1 minute ago, NJwx85 said:

You're going to go from 12" to 2" over a very short distance and that's going to be close to the line I indicated. Keep in mind the dew points are based on the 12z Euro so you can use your model of choice. Nobody knows for sure where exactly the snow stops, but the model consensus is between I-84 and I-90.

Its not that short of a distance though. Just looking at Euro It gives Poughkeepsie 1 foot and decreases precip to a few inches around I90. Thats 80-90 miles. It has 6+ well north of 84. Thats just one model but most others have similar numbers. 

[NJwx85]

2 minutes ago, HeadInTheClouds said:

Its not that short of a distance though. Just looking at Euro It gives Poughkeepsie 1 foot and decreases precip to a few inches around I90. Thats 80-90 miles. It has 6+ well north of 84. Thats just one model but most others have similar numbers. 

The gradient is going to be sharper than what the models indicate. Cannot tell you how many times recently that I was on the fringe and got absolutely nothing. 

[BxEngine]

Discuss the storm. Plenty of other websites to discuss each others mental issues. 

[friedmators]

.

[HeadInTheClouds]

1 minute ago, NJwx85 said:

The gradient is going to be sharper than what the models indicate. Cannot tell you how many times recently that I was on the fringe and got absolutely nothing. 

My point, 84 Is not on the fringe with a foot forecast,  I90 is on the fringe. 

[Gravity Wave]

1 minute ago, NJwx85 said:

The gradient is going to be sharper than what the models indicate. Cannot tell you how many times recently that I was on the fringe and got absolutely nothing. 

You always have to take this account if you're near the northern or western fringe with big, dynamic storms. Sometimes everything works out, but the subsidence from the deform band is rarely handled well, even by many of the mesos.

[jm1220]

9 minutes ago, HeadInTheClouds said:

Its not that short of a distance though. Just looking at Euro It gives Poughkeepsie 1 foot and decreases precip to a few inches around I90. Thats 80-90 miles. It has 6+ well north of 84. Thats just one model but most others have similar numbers. 

In the end I think it’s a sharper gradient than that. I agree that south of I-84 should be good, and near that northern edge could actually do quite well because that’s where ratios could be best and there’s usually a final heavy snow band that sets up there. But north of that it’s subsidence city along with the dry air and amounts drop fast. Guess we’ll see what can still happen but today’s trends aren’t great for Albany for example. 

[tdp146]

[HeadInTheClouds]

4 minutes ago, NJwx85 said:

The gradient is going to be sharper than what the models indicate. Cannot tell you how many times recently that I was on the fringe and got absolutely nothing. 

I hear ya on that. I was on the fringe with Jonas expecting 1-3 inches and saw 1-3 flakes. 

[Blizzardo]

1 minute ago, Gravity Wave said:

You always have to take this account if you're near the northern or western fringe with big, dynamic storms. Sometimes everything works out, but the subsidence from the deform band is rarely handled well, even by many of the mesos.

Subsidence has nothing to do with the northern cutoff. Thats a whole nother story and can also happen anywhere

[weatherbear5]

A bit early to call... but I think the NAM may come in a bit further south than 12z

[wdrag]

Hi!  I don't have any big changes for our forum... My thinking is we have a 6-12 hour blitz of with lingering lighter snows extending this to 20-24 hours. The EPS continues solid 1" to just s of the MA Pike and I agree with posters about sharp cutoff near or just n of I90.  I also have concerns about the I95-LI stretch  (PHl-NYC ) sleet/cold rain/junk mix after the first few hours off thump that will need traveler behavior modifications (S+ for 1-4 hours?) .  Still the EC EPS continues steadfast on a nose of max snowfall from near HAR to somewhere along or just s of I84 to near BOS?  

I don't have enough time to study the 12z cycle (Xmas cards).  This is the NWS collaboration.  I do think this will be high impact nor'easter. Not the severity that it could be because it's shorter duration and not quite the gradient but folks are going to be shoveling and my thinking, they don't want to be out traveling in our forum roughly 6P-3A. 

I have to think a slew of watches will post by 4PM...then we just have to do what the NWS does...  be patient, head for a reasonable blended solution and emphasize their points via social media.  I think our topic is good... probably a touch overdone on top 20 snow event.   Will NYC set a daily record snow tomorrow. I don't know. Can we get to 20" (several 20" reports) in our interior hilly forum... maybe but it's not my emphasis. If we see a widespread 6"+ snowstorm with a band of 12-15" ne PA/extreme nW NJ far se NYS into CT... I am satisfied, particularly since this has been modeled very consistently for days. LI/coastal NJ i our forum... no confidence yet on inches. 311P/14

 

One additional note: You may be noticing strange pockets of heavier and lighter qpf, ditto RH dry and wet fields at 700 and 500 MB. That's model signs of banding..modulation of the qpf fields.  I'd look at the srn edge of the 700-400 moisture for potential banding,.  313P/14