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

[MJO812]

Winter Storm Warning for NYC

8-12 inches

[nycsnow]

Winter Storm Warning

URGENT - WINTER WEATHER MESSAGE
National Weather Service New York NY
340 PM EST Tue Dec 15 2020

NJZ006-NYZ072>075-176>178-161200-
/O.UPG.KOKX.WS.A.0001.201216T1900Z-201217T1800Z/
/O.NEW.KOKX.WS.W.0001.201216T1900Z-201217T1800Z/
Hudson-New York (Manhattan)-Bronx-Richmond (Staten Island)-
Kings (Brooklyn)-Northern Queens-Northern Nassau-Southern Queens-
340 PM EST Tue Dec 15 2020

...WINTER STORM WARNING IN EFFECT FROM 2 PM WEDNESDAY TO 1 PM EST
THURSDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 8 to 12
  inches. Winds gusting as high as 45 to 50 mph.

* WHERE...Portions of northeast New Jersey and southeast New York,
  including New York City and northwestern Long Island.

* WHEN...From 2 PM Wednesday to 1 PM EST Thursday.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions could impact the morning or evening commute. Gusty
  winds and heavy wet snow could bring down scattered to numerous
  tree branches.

* ADDITIONAL INFORMATION...Snowfall amounts could be a bit lower
  than forecast along south coastal portions of the region if
  sleet mixes in Wednesday Night.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency.

Check local Department of Transportation information services for
the latest road conditions.

[David-LI]

3k NAM simulated Infrared. Could this be right and we see precipitation by 4 pm tomorrow? 

Take it with a grain of salt

[weatherpruf]

I must say, all the confusion around here, some saying its good others bad, I learn to look at the long time posters and see what they think. I think JM1220 knows these kinds of set ups pretty well; so JM, I'm looking to you....because I think it will be some snow and a lot of sleet. But it will still look nice. 

[NJwx85]

Winter Storm Warning here for 12-16 inches and gusts up to 45MPH.

[SnowGoose69]

The biggest difference a tick in the surface low track might make is in that snow early Thursday AM.  The mid-level lows are still going to cross the metro but if the surface low takes a 30 mile jog from where the NAM has it now that CCB like area could do more damage here 08-13Z Thu AM

[KeithB]

7 minutes ago, weatherpruf said:

I must say, all the confusion around here, some saying its good others bad, I learn to look at the long time posters and see what they think. I think JM1220 knows these kinds of set ups pretty well; so JM, I'm looking to you....because I think it will be some snow and a lot of sleet. But it will still look nice. 

I like this. Also, if things go bad...now we have someone we can blame

[Brian5671]

4 minutes ago, SnowGoose69 said:

The biggest difference a tick in the surface low track might make is in that snow early Thursday AM.  The mid-level lows are still going to cross the metro but if the surface low takes a 30 mile jog from where the NAM has it now that CCB like area could do more damage here 08-13Z Thu AM

will likely come down to a nowcast for some areas

[jm1220]

RGEM apparently still quite warm/tucked in for 18z run today. 

[Northof78]

WSW for 12" - 16" for W Essex...not bad, WSW for 12" - 20" for N/C NJ in Somerset County....45mph gusts....near blizzard conditions. 

[Juturna]

NWS Upton not buying into the warmer NAM from earlier.

 

Quote

The surface low will move NNE along the Mid Atlantic coastline
and then eastward off the Delmarva Wednesday night into
Thursday. Given the strong Arctic high to the north with
surface and low level temperatures at or below freezing, most
of the area should see an all snow event. The last several runs
of the NAM put this somewhat into doubt with a more amplified
upper trough and stronger mid level jet bringing in warmer air
aloft, also a dry slot late Wed night. With the ECMWF actually
trending colder and remaining slower, did not entirely buy this
scenario except for the lower boroughs of NYC and the south
shore/east end of Long Island.

The main change made with this update was trying to identify the
best potential for any mixing to occur. Though the Twin Forks
likely will mix with rain or sleet at some point, the warm nose
at 850mb was fairly minimal, becoming basically isothermal for a
few hours. This would occur in the middle of the storm so heavy
snow will have already occurred resulting in at least 3-6" of
snow. Obviously the exact intensity of the precipitation and the
ultimate track of the low play a significant role in
determining the strength of the warm nose at 850mb and ultimate
duration and potential to mix or change over to rain, so trends
in models regarding precipitation types will be monitored and
updated accordingly.

[SleetStormNJ]

3 minutes ago, jm1220 said:

RGEM apparently still quite warm/tucked in for 18z run today. 

Toss........

[nycsnow]

4 minutes ago, jm1220 said:

RGEM apparently still quite warm/tucked in for 18z run today. 

I don’t trust those maps because before they looked crappy and the high res maps weren’t as bad 

[forkyfork]

is it so hard to post a map

[wdrag]

HRRR thru 12z Thu: have a look... might be pretty good. Am confident of big snow back to near ALB and n of BGM  Borrowed from a modeler elsewhere. 

[jm1220]

Watch still in effect here for 3-10". Quite the range, pretty much how I see it. Covers all of Suffolk County so 3" is probably the twin forks, 6" or so here. 

[weatherpruf]

3 minutes ago, Brian5671 said:

will likely come down to a nowcast for some areas

Hmmm....all these storms come to nowcast it seems; kind of makes following a forecast somewhat redundant....but we do it anyway. Gluttons for punishment.

[friedmators]

5 minutes ago, SleetStormNJ said:

Toss........

Def toss.  Rain to 195 and Taint to NY/NJ Border.

[Stormlover74]

21 minutes ago, weatherpruf said:

Feb 2014 was forgettable around here, but it was always progged to be forgettable; we were forecast from the get go for warm nose. That one struggled to get to 3-4 of sleet here; the March sleet storm delivered more here. 

Really? I had a foot 5 miles away

[Stormlover74]

7 minutes ago, Juturna said:

NWS Upton not buying into the warmer NAM from earlier.

 

Not updated though

[loadletterpaper]

Are the model diagnostic discussions still a thing?  Can't find.

[LongBeachSurfFreak]

3 minutes ago, jm1220 said:

Watch still in effect here for 3-10". Quite the range, pretty much how I see it. Covers all of Suffolk County so 3" is probably the twin forks, 6" or so here. 

The big question for western li is does the temp stay below freezing. We haven’t seen that in some recent events that had a change over. But if it does snow removal will be very difficult with sleet and ice. I like 4” at my parents on the bay 6” at my place in Lynbrook and 10” at work on the far uws 

[nesussxwx]

24 minutes ago, David-LI said:

3k NAM simulated Infrared. Could this be right and we see precipitation by 4 pm tomorrow? 

Take it with a grain of salt

these things always like to come in early and leave early

[nesussxwx]

8 minutes ago, wdrag said:

HRRR thru 12z Thu: have a look... might be pretty good. Am confident of big snow back to near ALB and n of BGM  Borrowed from a modeler elsewhere. 

State College bullseye is looking more and more realistic imo.

[NYC10023]

6 minutes ago, weatherpruf said:

Hmmm....all these storms come to nowcast it seems; kind of makes following a forecast somewhat redundant....but we do it anyway. Gluttons for punishment.

every. single. year. 

it's comical to watch the meltdowns turn to jubilation (and back) with each run. 

but, here we are. Waiting for the next run, no less

[jdj5211]

I like to keep an eye on each run of the HRRR.  First place you may start to catch trends and movement of precip....that last run looks good so far... 

[wizard021]

2 minutes ago, jdj5211 said:

I like to keep an eye on each run of the HRRR.  First place you may start to catch trends and movement of precip....that last run looks good so far... 

hrrrr is worthless beyond 12hours.

[wizard021]

9 minutes ago, nesussxwx said:

State College bullseye is looking more and more realistic imo.

I doubt albany sees 20 inchces.

[romba]

RGEM Kuchera. Does Kuchera take sleet into account or treats it as 10:1?

 

[wizard021]

2 minutes ago, romba said:

RGEM Kuchera. Does Kuchera take sleet into account or treats it as 10:1?

 

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