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

[SnowGoose69]

Just now, jm1220 said:

I will say for whatever it's worth the GFS doesn't show the same warm nose the NAM has at 36hr on the soundings. Strange with a fairly strong southerly wind at 700-750mb. The 700 low does take a slightly better track on the gfs than the NAM. 

Its not even close either.  Normally the GFS would be like isothermal 0 or -1C and you just figure its under compensation for mid level WAA.  Its like -5C lol

[jm1220]

3 minutes ago, psv88 said:

 

You see our winter storm watch? 3-10"...wtf is that

Means we're essentially right on the line and they don't know what will happen lol. My point/click still says 8-14" though. Jackpot  

Long Beach only around an inch.  

[SnoSki14]

Still floored I'm under a WSW for 12-20" just west of Piscataway.

That's a bust waiting to happen.

[Allsnow]

3 minutes ago, Allsnow said:

12z euro

[NJwx85]

Gotta love that dynamic cooling signal on the 18z GFS as it moves from NE PA, across NNJ and into the LHV.

[SnowGoose69]

1 minute ago, Allsnow said:

12z euro

The Euro map probably includes sleet so those totals across LI/metro are probably lower.

[NJsnow89]

2 minutes ago, SnoSki14 said:

Still floored I'm under a WSW for 12-20" just west of Piscataway.

That's a bust waiting to happen.

What’s your location? I’m in Piscataway. 

[MJO812]

Wow gefs 

[HVSnowLover]

Gfs looks nice but with the low in that position I think most of the immediate area at least flips to sleet or rain for a brief time. Models look better than they did this morning though at least. 

[MJO812]

2 minutes ago, HVSnowLover said:

Gfs looks nice but with the low in that position I think most of the immediate area at least flips to sleet or rain for a brief time. Models look better than they did this morning though at least. 

Gefs is further south and east

[bluewave]

The GFS V15 is getting replaced by the v16 next year due to the cold bias. It will be the least reliable piece of guidance for this event.
 

https://dtcenter.org/sites/default/files/events/2020/1-fanglin-yang.pdf

Outstanding Issues
• PBL inversion
• Cold bias in the lower troposphere in winter
• Surface temperature biases

[MJO812]

[RCNYILWX]

Thanks! The storm you're referring to is probably 3/14/17. 

That's the one! I'll fix my original comment. Definitely a good cautionary system with respect to mid level warmth. I remember watching the mixing line surge northward on correlation coefficient on OKX and DIX during that event. 

 

You made a comment later that the models often underdo the warming aloft and that's absolutely right. It's tough to say yet that the NAM is handling it perfectly because even at this range it can be too amplified with key mass fields. That said, have seen it perform better than the globals several times out here re. warm nose aloft. Hopefully the Euro is capturing things well enough and a good chunk of the city and interior LI can manage to get several hours of heavy snow rates before mixing/dryslot.

 

 

 

 

 

[MJO812]

Gefs

[gravitylover]

1 hour ago, uncle W said:

Feb 61 had heavy snow from NYC northwest almost to the great lakes...it was later in the season and temperatures were zero before the storm...but it does happen...

Looks like the hill country SW of Syracuse got buried in this one.

1 hour ago, shadowsintherain said:

Ahh the good old days! Can’t believe I’ve been watching you folks that long! My God. Where does the time go???


.

The time? What about the hair... 

1 hour ago, wizard021 said:

Nam is 100% better , h5 low is further south we get hit backside with 2 to 4 inch hour rates for an hour .

5 decades of weather watching around here and I can only think of two or three times that backside snows actually amounted to anything of consequence. Christmas 02 being the most dramatic of them.

1 hour ago, RCNYILWX said:

Only wraparound/CCB that I can remember really working out for a storm that didn't have a good track overall for the city and western and central LI was the Christmas 2002 noreaster. I guess you could kind of group in the late Feb 2010 Snowicane but that was an odd beast of a storm.

As mentioned above. What a cool storm that was right? From a cold rain to a foot of glue in just a few hours. The biggest problem was how wet the lower layers were and how hard they froze overnight. That was one of the worst shoveling episodes I've ever experienced and I had to get it done so I could leave home at 6am for work. No sleep at all that night...

43 minutes ago, wizard021 said:

That model is crazy. How is Coastal Maine getting 20 to 30 inches.

The tiny sliver goes right over the Mt A massif. There's a 'big rock' named Mt Agamenticus in that corner and it has a habit of drawing whatever last little bit of storm is passing by and amplifying it. When the ski area was operational they would often record absurd snowfall amounts when the mountains in the vicinity would show a few inches. Now it's just a conglomeration of awesome mt bike trails but it still gets crazy snow.

[F5TornadoF5]

3 minutes ago, MJO812 said:

Cut those almost in half and that would be my forecast, specifically for our area.

[mikem81]

8 minutes ago, JoshSnow said:

Anthony do you have the GEFS clownmap?

You can see that around 4 of the members are too close to the coast near NJ and the others  are in perfect position (excluding the 4 that are sun-tanning in bermuda)

You 

[Sn0waddict]

Quite the dry slot on the HERPES. Sheesh

[sussexcountyobs]

4 minutes ago, Sn0waddict said:

Quite the dry slot on the HERPES. Sheesh

I wouldn't mess with HERPES. You'll always regret it.

[David-LI]

5 minutes ago, Sn0waddict said:

Quite the dry slot on the HERPES. Sheesh

Alright now they're naming models after infectious diseases.

[MJO812]

9 minutes ago, Sn0waddict said:

Quite the dry slot on the HERPES. Sheesh

Alot of snow for NYC

[NJwx85]

[SnowGoose69]

The one similarity between the RGEM and GFS (especially the HRDPS) is that they both want to go just snow or rain and not so much have the period of sleet

[MJO812]

7 minutes ago, NJwx85 said:

Snowmap looks great 

[HVSnowLover]

Surface temps will rise above freezing righ

3 minutes ago, SnowGoose69 said:

The one similarity between the RGEM and GFS (especially the HRDPS) is that they both want to go just snow or rain and not so much have the period of sleet

surface I would think rises above freezing along immediate coast once precip lightens so rain might make more sense. If the upper layers warm further inland then sleet seems more likely (by inland I’m even talking like anywhere not on the Jersey coast or south shore of LI) 

[weatherpruf]

36 minutes ago, SnoSki14 said:

Still floored I'm under a WSW for 12-20" just west of Piscataway.

That's a bust waiting to happen.

Well a local store sold 12 snowblowers today so I suspect collusion of some sort.

[romba]

1 minute ago, JoshSnow said:

Why don’t u post it what happens after that hour! 

Maps stopped loading on tidbits

[MJO812]

5 minutes ago, JoshSnow said:

Why don’t u post it what happens after that hour! 

[weatherpruf]

27 minutes ago, RCNYILWX said:

That's the one! I'll fix my original comment. Definitely a good cautionary system with respect to mid level warmth. I remember watching the mixing line surge northward on correlation coefficient on OKX and DIX during that event. 

 

You made a comment later that the models often underdo the warming aloft and that's absolutely right. It's tough to say yet that the NAM is handling it perfectly because even at this range it can be too amplified with key mass fields. That said, have seen it perform better than the globals several times out here re. warm nose aloft. Hopefully the Euro is capturing things well enough and a good chunk of the city and interior LI can manage to get several hours of heavy snow rates before mixing/dryslot.

 

 

 

 

 

The day before that storm I was being my usual Eeyore self and saying that March storms rarely deliver more than a foot in the immediate NYC area, but not because I know anything about the science its just history. No less than Mitchell Volk came on and basically said I was right ( for the wrong reasons maybe ) and that he thought there would be more sleet. Not only was there, but it went way north of where it was supposed to, but those areas had a longer duration snow and still did well. We got about 3-6 of garbage here.

[jm1220]

7 minutes ago, JoshSnow said:

It fills in and it’s all snow! I don’t think there’ll be a dry slot if the low doesn’t go overhead. Look at the euro and gfs

What we’re looking for in terms of the dryslot is the 700mb low track not the surface.