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

[Rjay]

There's some really wind potential with this one too.  

[Nibor]

7 minutes ago, Rjay said:

Weenie comment but I really want this to close off south of us

 

I think that's the first run of the euro where it closed off at 500mb. 0z CMC did so as well a little further south than the euro.

[MJO812]

Euro is basically a blizzard for NYC

Euro shows near a foot for NYC. Slow this down some more and cut off south of NYC  like the cmc and this would be a MECS.

[Neblizzard]

2 minutes ago, Nibor said:

I think that's the first run of the euro where it closed off at 500mb. 0z CMC did so as well a little further south than the euro.

Also notice the enhanced PNA spike, very encouraging trends 

[wizard021]

The cmc is really doing fine , must be upgraded . 

[Stormlover74]

Just now, wizard021 said:

The cmc is really doing fine , must be upgraded . 

Let's wait a few days before congratulating it

[LibertyBell]

2 hours ago, TriPol said:

 

I feel bad for people in Montauk.

 

those clown maps always do that

[LibertyBell]

1 hour ago, Rjay said:

There's some really wind potential with this one too.  

so it really might be like Boxing Day 2010

[Nibor]

6z gfs another huge hit. Really tucked in. 

[wizard021]

Would love to see those gefs members over NJ. Move east . Some are really tucked in like the icon. 

[wdrag]

Written with maybe too much faith in the consensus through the 06z/12 cycle??  Take this with a grain of salt .. i just am reading what i THINK  the consensus is telling me. 

Now stakes in by Sunday night?  Snow blowers the ready? Hope so, at least for the interior. Until something in the modeling breaks down, thinking of planning ahead is a good idea.

So far so good for the nor'easter snowstorm through the 06z/12 cycle.  I'll add some support graphics.  Model trends, maybe minor south in some cases but overall the NAEFS says stay the course!  I will not call this a blockbuster snow storm yet with near blizzard conditions for parts of NJ/s CT since rain could mix in, and timing 3 hrs of 1/4S+ and/or BS, plus gusts in excess of ~35 MPH is fraught with uncertainty 5 days in advance and could more easily not occur.  However, modeling continues, so far,  to allow for an easy over a foot in some parts of our area.  BUTTTTT... thermal profiles on the EC are dangerously close to a mix or rain across NJ s of I80 including NYC LI.... AND...modeling can break down and weaken the cues. 

So, barring a greater flattening of the 00z/12 ensembled 500MB forecast upper air short wave which would mean less lift, less developed closed lows at 850-700MB, I am thinking the jackpot of big time powder 1 foot plus is the I84 corridor (ne PA-extreme nw NJ/se NYS interior CT) to near I90. A wetter snow down here near and s of I80 (my non scientific heart attack amounts if all snow for those with vulnerable conditions).  This would be associated with not only DGZ, but snow ratios well above 10 to 1, maybe 13 to 1???? I don't have the snow ratio tool so I cannot be sure. The other factor, the southern edge of the 700MB RH in the northern semicircle of the probable weak 700MB low, usually slow movement, favorable for a 700MB front and associated banding. Again, BARRING a future weakening of the model 500MB short wave and associated fraying of 700 and 850MB lows.  

Coastal flooding: A moderate event seems probable Thursday morning, for LI/NJ coasts (minor Wednesday morning) and must absolutely follow NWS guidance on this--they have some tools I don't have.  Just quickly referenced the Stevens output and knowing that we will see 45 MPH wind gusts on LI/NJ immediate coast (60 MPH gusts possible s of LI on the open water near 44025?), and the ensembled low pressure near 995MB and the high near 1034MB over Quebec and ~24 hours or more of Ekman transport suggests to me a significant coastal flood event. Timing of onshore winds and lowering of pressure is always critical but with an an astronomically high tide, it's easier to flood. 

Graphics: NWS ensembled consensus for 3+ inches of snow Wednesday. , their human interactive assessment of qpf amounts (the heavier 1.5" purple is usually associated with rain, the weather.us presented EPS ECMWF low pressure for Thursday morning (ever deeper consensus and nicely clustered--note the big high over Quebec., a snapshot GEFS probabilistic of 6+" of snow (10 to 1 ratios)-Yellows pushing 70-75%. I just cant post the ECMWF amounts yet...  but suffice to say it's been spotting 18" here and there for the past 5 cycles in the northeast and is tending to settle on a SNE PA/nw NJ axis.   I want to wait another day before I lock in on the EC.  557A/12

 

 

 

[crossbowftw3]

Liking where I'm sitting more and more here. Aside from the GFS almost every single one likes the Catskills for 8"+ on this one. Today's going to be critical to watch the models, especially GFS.

 

@wdrag how high do you think ratios get inland? I was thinking up to around 15:1 but with P&C forecast giving me a high of 27 and a low of 15 Wednesday I'd think maybe a bit higher?

[lee59]

I'm just happy there is something ligit to track. To early to say for sure, who gets what.

[SnoSki14]

36 minutes ago, NJsnow89 said:

Gfs is a bit concerning for the coast. Low has trended further north. 

Ensembles are steady run to run so I think it's just noise. 

However the risk of a tucked in solution is out there. 

[wdrag]

1 hour ago, crossbowftw3 said:

Liking where I'm sitting more and more here. Aside from the GFS almost every single one likes the Catskills for 8"+ on this one. Today's going to be critical to watch the models, especially GFS.

 

@wdrag how high do you think ratios get inland? I was thinking up to around 15:1 but with P&C forecast giving me a high of 27 and a low of 15 Wednesday I'd think maybe a bit higher?

I don't really know... BUFKIT allows access to that.  It could be 15 to 1.  Bottom line lots of powder. (EC is seemingly too strong but might be right...if so,  all the better for the healthy snow lovers.. i just need to look for break downs.  Seemed to me the 06z/GEFS slightest edge south but .. keeps our forum in big time axis, especially I84-I80 (exclusive of LI warming aloft).

[Heisy]

Man a lot of those EPS lows are way too tucked in for my liking. We need that trend to stop immediately

[Tatamy]

06z GEFS Mean snow depth at 138 hours

[SnowGoose69]

2 minutes ago, JoshSnow said:

Chris, you seriously considering icon? I never even look at that model, worst global model for sure

I think he’s just saying the system would track more tucked with a weaker PNA.  The ICON verbatim would probably still be 5-10 inches of snow for anyone north of Sandy Hook and west of Islip before they changeover over but the ICON of course doesn’t resolve the cold air correctly and has like 1 hour of snow.  This event barring some sort of massive change in several parameters even if it flips to liquid will probably be in the category of a January 87 March 93 February 2014 in regards to how much snow you see before a flip 

[wdrag]

If you like the Euro...  then folks LI and s of I80 need to be aware of probably less than 10 to 1 snow ratios, a water snow and sleet mix (rain coasts).  The 850 and 700 temps are not that cold  flaring with -2C. 

[tim]

32 minutes ago, JoshSnow said:

Tucked would be fine for NYC not for eastern Long Island!

...i'll be on the razors edge again along with "eastern long island" who is in riverhead..whats 

the old adage??..."got to smell the rain to get the heavy snow"..

[bluewave]

18 minutes ago, JoshSnow said:

Chris, you seriously considering icon? I never even look at that model, worst global model for sure

That’s not what I am saying. It’s pretty rare for any individual model or ensemble group to nail a winter storm track down from 5 days out. But the models and ensemble members show some PNA spread which is normal. Even among the EPS members, we do better with the members with a stronger ridge near California. It allows the UL to dig closer to the TV instead of GL. The further south the UL digs, the better insurance policy we have against a hugger track. We may have to wait until the UL comes ashore near California  tonight into Sunday for a more definitive answer.

[Allsnow]

4 minutes ago, bluewave said:

That’s not what I am saying. It’s pretty rare for any individual model or ensemble group to nail a winter storm track down from 5 days out. But the models and ensemble members show some PNA spread which is normal. Even among the EPS members, we do better with the members with a stronger ridge near California. It allows the UL to dig closer to the TV instead of GL. The further south the UL digs, the better insurance policy we have against a hugger track. We may have to wait until the UL comes ashore near California  tonight into Sunday for a more definitive answer.

Why have the Costal storms tracks return? Monday and Wednesday will now make it 4 for the month 

[Zelocita Weather]

It’s a balance between the low position and the confluence/cold air, we have all seen a low pressure tucked onto the Delaware beaches, but NYC not see a flake due to confluence (Feb 5 2010); lots of fresh very cold air and a lot of moisture should make this at least a 6” storm, but very well could be 1’ plus...

[bluewave]

2 minutes ago, Allsnow said:

Why have the Costal storms tracks return? Monday and Wednesday will now make it 4 for the month 

Blocking. First the big +PNA spike early in the month and now the strong block near Greenland and the Pole. 

[Allsnow]

Just now, Zelocita Weather said:

It’s a balance between the low position and the confluence/cold air, we have all seen a low pressure tucked onto the Delaware beaches, but NYC not see a flake due to confluence (Feb 5 2010); lots of fresh very cold air and a lot of moisture should make this at least a 6” storm, but very well could be 1’ plus...

The confluence will make or break this event. 

[Allsnow]

All the eps members are a significant snowfall for nyc 

[crossbowftw3]

1 minute ago, Allsnow said:

All the eps members are a significant snowfall for nyc 

Member 1 looks kinda odd compared to the rest 

[CIK62]

Snow totals summary: Mon.  +  Wed./Thurs.    EURO   2.5" + 14.0",   CMC   0 0" + 17.0",    GFS  0.5" + 13.0".       Non gust winds still 18-25mph.

Cautions......Two fast movers, borderline S/R for City, but 2"+ to work with.     

Euro is running between 15-35 for a week.   GFS still goes to the 60's on Christmas.     With snow still on the ground?!    Come on man. >>>>>>>   The 06Z just lost 30 degrees on the Highs for 25th,26th. !!!

Amended:        Cobb Method   GFS 0Z is all Snow for NYC............. 21" in 19 hours!

[Rjay]

35 minutes ago, wdrag said:

If you like the Euro...  then folks LI and s of I80 need to be aware of probably less than 10 to 1 snow ratios, a water snow and sleet mix (rain coasts).  The 850 and 700 temps are not that cold  flaring with -2C. 

Thanks for all your input.  It's greatly appreciated and I love that your enthusiasm for  all types of weather has stayed with you for all these years.  

This part isn't for you Walt, but I want our members to remember a few things if they decide to talk about ratios today.   Firstly, it's probably too early to talk about ratios in a serious manner.  Secondly, if you do want to talk about ratios, you really need to look at the soundings.  Thirdly, don't discount the wind when trying to figure out ratios.

[Ericjcrash]

3 minutes ago, Rjay said:

Thanks for all your input.  It's greatly appreciated and I love that your enthusiasm for  all types of weather has stayed with you for all these years.  

This part isn't for you Walt, but I want our members to remember a few things if they decide to talk about ratios today.   Firstly, it's probably too early to talk about ratios in a serious manner.  Secondly, if you do want to talk about ratios, you really need to look at the soundings.  Thirdly, don't discount the wind when trying to figure out ratios.

Yeah, its going to be pretty windy and that's always underplayed when people assume ratios.