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

[North and West]

3 minutes ago, SnoSki14 said:

Knock on wood but anyone getting 6"+ amounts will have a white Christmas this year.

The grinch storm is gone, we still have blocking in place, and things actually get kinda favorable for more snow last week of December if the GEFS is correct. 

Models are also raising the heights around Alaska, which would help a lot with the cold supply. 

These models have mood swings wilder and more unpredictable than my children fighting over halloween candy bartering.

[wizard021]

9 minutes ago, Brian5671 said:

the 2 inch amts were over done.   You don't need a big bomb to get 12 inches of snow-PD storm in 2003 was actually weak and many got 18 inches

Confluence looking strong 

[T5403CG]

Moved to LI (NW Nassau) from DC area 18 months ago, hoping I’d get a bit more snow. Last year wasn’t great! Fingers crossed for this. One thing that’s interesting to me is that down there I would have seen a 20 mi difference as more or less unpredictable, but everything clearly shows quite a diff between North Shore and South Shore on LI that I suppose is relatively common?

Yes... I live in West Islip... a few years back we had a storm that dumped 32"+ in Commack... Near northern state... I live 6-7 miles south... and on the South Shore we lost about 12" to rain before it turned to snow...

That 5+ miles can make such a huge difference in accumulation...

Sent from my moto g power using Tapatalk

[Snowshack]

9 minutes ago, SnoSki14 said:

Knock on wood but anyone getting 6"+ amounts will have a white Christmas this year.

The grinch storm is gone, we still have blocking in place, and things actually get kinda favorable for more snow last week of December if the GEFS is correct. 

Models are also raising the heights around Alaska, which would help a lot with the cold supply. 

Sure would be a nice change to have a cold and snowcovered runup to the holidays but I'm not buying yet.

 

[NJwx85]

14 minutes ago, Brian5671 said:

the 2 inch amts were over done.   You don't need a big bomb to get 12 inches of snow-PD storm in 2003 was actually weak and many got 18 inches

It's extremely difficult to get high amounts of precipitation to fall when you're ramming moisture into brick wall of dense, dry air. We would have received higher amounts if the coastal had been stronger due to stronger dynamics. 

[MJO812]

Great low spot

[HVSnowLover]

46 minutes ago, David-LI said:

12z euro totals

Yea this is why I'd be a little worried north of I84. This run is still okay but models seeming to pick up on the impact of confluence on the northern extent of precip

[MJO812]

Eps is a really long duration storm

[NorthShoreWx]

32 minutes ago, Cerinthe Major said:

Moved to LI (NW Nassau) from DC area 18 months ago, hoping I’d get a bit more snow. Last year wasn’t great! Fingers crossed for this. One thing that’s interesting to me is that down there I would have seen a 20 mi difference as more or less unpredictable, but everything clearly shows quite a diff between North Shore and South Shore on LI that I suppose is relatively common?

Relatively common.  A good way to think of it is the south shore folks are on the beach and the north shore folks are 10 or 15 miles inland.  The LI Sound isn't insignificant, but it's a much smaller body of water and after October also colder.  In 2015, a significant portion of the Sound froze over.  if anything, it adds more snow than it detracts.

[White Gorilla]

26 minutes ago, HVSnowLover said:

Yea this is why I'd be a little worried north of I84. This run is still okay but models seeming to pick up on the impact of confluence on the northern extent of precip

Will gladly take this here in POU at a foot.  

[crossbowftw3]

8 minutes ago, HVSnowLover said:

Yea this is why I'd be a little worried north of I84. This run is still okay but models seeming to pick up on the impact of confluence on the northern extent of precip

If another tick or two happens southeast we will likely end up out of warning amounts. Models finally picking up confluence...as I had always said this had a chance to evolve to a 95 crusher and it's already getting there: will us north of 84 slip out of warning level totals remains to be seen 

[SnowGoose69]

If you look at the 700 temps/low even the 12Z ECMWF is darn close for a period near JFK/SI.  The system is still a hybrid Miller B scenario to an extent so the lows mature a nose close to being too late where the 700 low is displaced.  Verbatim a shift of 30 miles south on the 12Z Euro is ideal for NYC itself for sure

[jm1220]

3 minutes ago, NorthShoreWx said:

Relatively common.  A good way to think of it is the south shore folks are on the beach and the north shore folks are 10 or 15 miles inland.  The LI Sound isn't insignificant, but it's a much smaller body of water and after October also colder.  In 2015, a significant portion of the Sound froze over.  if anything, it adds more snow than it detracts.

In March 2019 there were definitely differences between my parents’ place in Long Beach and here in S Huntington snow cover wise and amount that fell. I had 10-12” or so across 3 systems and they had maybe a few inches. 

[RU848789]

Pretty happy with 12Z.  My thoughts, for what they're worth...

Basically, the Euro, UK and CMC all moved a bit SE with their snow fields, as the confluence was a bit stronger, so the track of the low was a bit further SE, meaning the snow/rain (or snow/sleet) lines moved SE a bit (like 10-20 miles, which isn't a lot, but makes a big difference for some), more towards what the GFS had been showing - and the GFS moved significantly further NW with its track and snow field, meaning the models are closer together than they were the last 2 cycles, but still some differences obviously.  Models should in theory converge as one gets closer to an event (every model will show almost the exact same forecast 1 hr into the future), though, but good to see.  

If you live along or NW of the 95 corridor, prepare for a major (8" or more) snowstorm, with 12" or more possible especially just NW of 95 and anywhere NW of there. Just SE of 95 and towards the coast will likely be the battleground for snow/sleet/rain at times. Also by early Thursday, after about 1 am, most folks should be snowing and the winds will increase to blizzard levels, so it should be pretty wild from maybe 1 am to 7 am.  Let's hope for no nasty surprises on this one, especially after last year's fiasco.  I think we're good, though, unless you're at the NJ coast and even they'll likely still have some fun on the backend.  NWS has 15" at my house - that's about my thinking too.  Make it so, lol  

[NJwx85]

7 minutes ago, MJO812 said:

Eps is a really long duration storm

That's because the timing is different within the individual members.

[jm1220]

1 minute ago, SnowGoose69 said:

If you look at the 700 temps/low even the 12Z ECMWF is darn close for a period near JFK/SI.  The system is still a hybrid Miller B scenario to an extent so the lows mature a nose close to being too late where the 700 low is displaced.  Verbatim a shift of 30 miles south on the 12Z Euro is ideal for NYC itself for sure

Yep- this is a situation IMO where we’re looking at dual pol to see where the sleet line ends up. Hopefully it stays just off the beaches. I’m more interested in those mid level low tracks than anything. 

[the_other_guy]

15 minutes ago, NorthShoreWx said:

Relatively common.  A good way to think of it is the south shore folks are on the beach and the north shore folks are 10 or 15 miles inland.  The LI Sound isn't insignificant, but it's a much smaller body of water and after October also colder.  In 2015, a significant portion of the Sound froze over.  if anything, it adds more snow than it detracts.

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

[weatherbear5]

11 minutes ago, SnowGoose69 said:

If you look at the 700 temps/low even the 12Z ECMWF is darn close for a period near JFK/SI.  The system is still a hybrid Miller B scenario to an extent so the lows mature a nose close to being too late where the 700 low is displaced.  Verbatim a shift of 30 miles south on the 12Z Euro is ideal for NYC itself for sure

Looks to me like the warmest 700mb gets on LI is about -5C? Def much colder than the 6z run

 

[Blizzardo]

I wouldn't want to be any further north than the NJ/NY state line. That high is going to press and it will always win. 

[NJwx85]

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.

[friedmators]

Just now, Blizzardo said:

I wouldn't want to be any further north than the NJ/NY state line. That high is going to press and it will always win. 

Yea I tend to agree with this.  Definitely liking my spot a few miles west of the 78/287 intersection. As opposed to Edison where I used to be.

[jm1220]

3 minutes ago, weatherbear5 said:

Looks to me like the warmest 700mb gets on LI is about -5C? Def much colder than the 6z run

 

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. 

[weatherbear5]

1 minute 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. 

Yeah, I agree. He just said 700 which I took literally, but it’s probably just below that in reality haha

 

[crossbowftw3]

5 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.

That cutoff is basically right over my head. Not great. 

[NorthShoreWx]

10 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

I think we're on the same page.  White Plains is farther inland than Huntington which is farther inland than Babylon.  LIS shouldn't be treated as just another lake, but it can't hold a candle to the ocean.

[weatherpruf]

5 minutes ago, friedmators said:

Yea I tend to agree with this.  Definitely liking my spot a few miles west of the 78/287 intersection. As opposed to Edison where I used to be.

I don't think Edison will be in a bad spot from what I can see. In a big storm there usually isn't much daylight between Lebanon and Edison. Boxing Day was one, with Hunterdon County being just a bit too far west, March 2018 was another, with portions of Middlesex County being a bit too far east for the best ratios. Any December storm is welcome if it can put down some decent cover.

[NJwx85]

2 minutes ago, crossbowftw3 said:

That cutoff is basically right over my head. Not great. 

I think you're find as long as you're South of 84. Once North of there you'll get some snow but it won't be like further South.

[WarrenCtyWx]

6 minutes ago, Blizzardo said:

I wouldn't want to be any further north than the NJ/NY state line. That high is going to press and it will always win. 

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

[friedmators]

1 minute ago, weatherpruf said:

I don't think Edison will be in a bad spot from what I can see. In a big storm there usually isn't much daylight between Lebanon and Edison. Boxing Day was one, with Hunterdon County being just a bit too far west, March 2018 was another, with portions of Middlesex County being a bit too far east for the best ratios. Any December storm is welcome if it can put down some decent cover.

This is true.  Its the marginally events like today where Ive been snowing most of the day and its rain down there.

[crossbowftw3]

1 minute ago, NJwx85 said:

I think you're find as long as you're South of 84. Once North of there you'll get some snow but it won't be like further South.

30 miles north of 84, and under 10-15 miles from where that line is set up. I have to imagine further adjustments will be made. 

 

Still thinking failure mode will be 3-6 or maginal warning.