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

[Nibor]

[Nibor]

[Nibor]

3k nam is kinda ugly...

 

[Nibor]

For what it's worth, experimental long range HRRR that ran at 6z

[F5TornadoF5]

Upton now has Winter Storm Warnings for all of Suffolk County

 

URGENT - WINTER WEATHER MESSAGE
National Weather Service New York NY
347 AM EST Wed Dec 16 2020

NYZ078-080-179-162100-
/O.UPG.KOKX.WS.A.0001.201216T1900Z-201217T1800Z/
/O.EXA.KOKX.WS.W.0001.201216T1900Z-201217T1800Z/
Northwestern Suffolk-Southwestern Suffolk-Southern Nassau-
347 AM EST Wed Dec 16 2020

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

* WHAT...Heavy snow expected. Total snow accumulations of 6 to
  13 inches. Winds gusting as high as 50 mph.

* WHERE...Northwestern Suffolk, Southwestern Suffolk and
  Southern Nassau Counties.

* WHEN...From 2 PM this afternoon to 1 PM EST Thursday.

* IMPACTS...Travel could be very difficult to impossible. The
  hazardous conditions could impact the morning or evening
  commute. Gusty winds could bring down tree branches.

* ADDITIONAL INFORMATION...There is still some uncertainty with
  how much, if any mixing occurs Wednesday night. Snowfall amounts
  could be a bit lower than forecast along south coastal portions
  of the region if more mixing occurs.

 

URGENT - WINTER WEATHER MESSAGE
National Weather Service New York NY
347 AM EST Wed Dec 16 2020

NYZ079-162100-
/O.UPG.KOKX.WS.A.0001.201216T1900Z-201217T1800Z/
/O.EXA.KOKX.WS.W.0001.201216T1900Z-201217T1800Z/
Northeastern Suffolk-
347 AM EST Wed Dec 16 2020

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

* WHAT...Heavy snow expected. Total snow accumulations of 7 to
  10 inches. Winds gusting as high as 50 to 55 mph.

* WHERE...Northeastern Suffolk County.

* WHEN...From 2 PM this afternoon to 1 PM EST Thursday.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions could impact the morning or evening commute. Gusty
  winds could bring down tree branches.

* ADDITIONAL INFORMATION...There is still some uncertainty with
  how much, if any mixing occurs Wednesday night. If more mixing
  occurs, snowfall amounts will be lower.

 

URGENT - WINTER WEATHER MESSAGE
National Weather Service New York NY
347 AM EST Wed Dec 16 2020

NYZ081-162100-
/O.UPG.KOKX.WS.A.0001.201216T1900Z-201217T1800Z/
/O.EXA.KOKX.WS.W.0001.201216T1900Z-201217T1800Z/
Southeastern Suffolk-
347 AM EST Wed Dec 16 2020

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

* WHAT...Heavy snow expected. Total snow accumulations of 4 to 10
  inches. Winds gusting as high as 50 to 55 mph.

* WHERE...Southeastern Suffolk County.

* WHEN...From 2 PM this afternoon to 1 PM EST Thursday.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions could impact the morning or evening commute. Strong
  winds could cause tree damage.

* ADDITIONAL DETAILS...There is still some uncertainty with how
  much, if any mixing occurs Wednesday night. If more mixing
  occurs, snowfall amounts will be lower.

 

 

 

 

 

[Nibor]

6z Reggie

[F5TornadoF5]

Looks like some slight improvement on 6z rgem compared to 00z.

[F5TornadoF5]

6z

6z



00z

[Nibor]

Tidbits has more panels. Changes to rain on LI on the rgem.

[SnowGoose69]

2 minutes ago, Nibor said:

Tidbits has more panels. Changes to rain on LI on the rgem.

The biggest change from 18-24 hours ago is that for places like N Queens Bronx Manhattan models are colder and if any sleet or rain does occur it’s probably not til 06Z where as 02-04Z was more possible earlier.  Similar changes have happened for south Queens/LI where the changeover is now probably 05Z (maybe 04) but it seems more rainy or dry slotty now vs sleet(3km NAM says otherwise).  I am more confident saying 8-12 at LGA now and probably 7-10 at JFK.  I wouldn’t be shocked either way if the mix line overachieved and still made it to LGA and a tad beyond or if it never even made it to Long Island.  After all, those two scenarios involve maybe a 20 mile difference in the end 

[USCG RS]

3 hours ago, wizard021 said:

I am going to be right. 

 

All hail and bow at my feet 

Is what I believe you were trying to say

[MJO812]

Great overnight  runs

Let the fun begin

[weatherpruf]

4 hours ago, MJO812 said:

GFS and Euro give NYC 15 inches 

 

Looks like a classic 6-8 maybe more of a snow to sleet situation. Would you have taken that last year and been thrilled? Two years ago? And while it is totally unscientific, at least in NJ, a decent snow in Dec usually portends at least a few more events later on; personally I need something to pay attention to than current world events....

[Franklin0529]

10 minutes ago, MJO812 said:

Great overnight  runs

Let the fun begin

U think the coastal Monmouth county see any accumulation

[JC-CT]

Can you "unjump" off a cliff?

[SnowGoose69]

13 minutes ago, weatherpruf said:

Looks like a classic 6-8 maybe more of a snow to sleet situation. Would you have taken that last year and been thrilled? Two years ago? And while it is totally unscientific, at least in NJ, a decent snow in Dec usually portends at least a few more events later on; personally I need something to pay attention to than current world events....

This will likely be the biggest event of the winter I think.  I still expect La Niña background state eventually takes over.  It might not be til late January but I expect the majority of snow this winter still falls before 1/20

[weatherpruf]

4 minutes ago, JC-CT said:

Can you "unjump" off a cliff?

Only online...

[weatherpruf]

2 minutes ago, SnowGoose69 said:

This will likely be the biggest event of the winter I think.  I still expect La Niña background state eventually takes over.  It might not be til late January but I expect the majority of snow this winter still falls before 1/20

That happened in the 2011 La Nina...but we had serious blocking that overcame anything else.....in my area after the last Jan storm it was over except for the wicked ice event in Feb. 

[Big Jims Videos]

18 minutes ago, Franklin0529 said:

U think the coastal Monmouth county see any accumulation

Highly doubt it unless there's a band at the end which lingers over Monmouth.  But I do think a flip to snow tomorrow morning will happen for a time and the wind could make it look fun for a bit.  

[wdrag]

 

543AM 12/16: No change in thinking including uncertainties along I95 which to me means we have a chance to exceed this winter, what will occur NYC-LI-coastal NJ tonight.  I just cannot shake the basics: S+ axis is usually 90 miles left of the 850 low and the northern half of the 700MB low and the deformation zone near 500 MB with contribution from the nose of the 850MB  50-65 kt easterly jet (moisture transport). This favors I84 and banding casts northwest to a central PA - east central NY area (roughly IPT-ALB) where 20-25" seem probable within 60 miles of that axis - at least in the high terrain, but must consider mountain shadow lesser amounts in the leeward valleys.  There a multiple models showing that axis.  In our forum, I think most everyone will see a period of sleet near or after midnight and that the bulk of the snow occurs in a 6-10 hour period prior ~ midnight, but that there will be a tail of moderate to heavy snow toward dawn with still 1-4" after sunrise Thursday on top of whatever occurs before sunrise---the heavier 4" potential ne PA, extreme nw NJ, se NYS and CT {where 5" may occur in 2-3 hours after sunrise Thursday}.  Drifts to 4 feet possible ne PA, se NYS and northern CT where 18" accumulates since winds will gust 30-40 Mph at times overnight. NYC CP still 6-10" in my mind but shakey and may be too high because of only 10-1 snow ratios at best, sleet and possibly rain compacting as well as temps near 33F at times during the night.  The power outage concerns continue near I95 with 45-50 MPH gusts (9P-6A). Coastal flooding - please see NWS offices for minor or moderate near the time of high tide Thursday morning. Finally, even if it rains or is above freezing w LI and Monmouth/northern Ocean County NJ tonight--- there could be sudden icing near sunrise Thursday when the wind switches from northeast to north and drops temps 5-10F in an hour,  and iceing the residue  and make travel very hazardous again in leftover new snowfall. Otherwise temps in the I84 corridor ~20-25F throughout the event.  Will add some graphics by 6AM on wherever the last page of the thread.  NOT a top 20 for NYC...best chance is MPO-POU axis in our forum.  This is my last topic update for this event. 

Will begin a storm accumulation obs  (snow/rain/sleet/damaging wind/coastal flooding) and nowcast topic by 6A to begin to be used once the snow begins-which I think will be between 1-4PM in our NJ/PA/w LI part of there forum. 

Graphics: my last on adding prestorm graphics.

NWS experimental severity index, the NWS snowfall forecast for our area as per 5A/16. 00z/16 EPS 10 to 1 snow ratio snowfall--i still think too high se edge and then snow ratios will magnify I84 corridor northwestward  NWS probabilistic 6+ and 18+. (Note NYC prob of 6+ is not that high). The 00z/16 SPCHREF gives us a better chance of exceeding 6" but the edges are always shaky. SPC SREF plumes for NYC. Please use all as options and may your expectations verify-just be realistic. 

 

[Heisy]

9 minutes ago, wdrag said:

 

 

543AM 12/16: No change in thinking including uncertainties along I95 which to me means we have a chance to exceed this winter, what will occur NYC-LI-coastal NJ tonight.  I just cannot shake the basics: S+ axis is usually 90 miles left of the 850 low and the northern half of the 700MB low and the deformation zone near 500 MB with contribution from the nose of the 850MB  50-65 kt easterly jet (moisture transport). This favors I84 and banding casts northwest to a central PA - east central NY area (roughly IPT-ALB) where 20-25" seem probable within 60 miles of that axis - at least in the high terrain, but must consider mountain shadow lesser amounts in the leeward valleys.  There a multiple models showing that axis.  In our forum, I think most everyone will see a period of sleet near or after midnight and that the bulk of the snow occurs in a 6-10 hour period prior ~ midnight, but that there will be a tail of moderate to heavy snow toward dawn with still 1-4" after sunrise Thursday on top of whatever occurs before sunrise---the heavier 4" potential ne PA, extreme nw NJ, se NYS and CT {where 5" may occur in 2-3 hours after sunrise Thursday}.  Drifts to 4 feet possible ne PA, se NYS and northern CT where 18" accumulates since winds will gust 30-40 Mph at times overnight. NYC CP still 6-10" in my mind but shakey and may be too high because of only 10-1 snow ratios at best, sleet and possibly rain compacting as well as temps near 33F at times during the night.  The power outage concerns continue near I95 with 45-50 MPH gusts (9P-6A). Coastal flooding - please see NWS offices for minor or moderate near the time of high tide Thursday morning. Finally, even if it rains or is above freezing w LI and Monmouth/northern Ocean County NJ tonight--- there could be sudden icing near sunrise Thursday when the wind switches from northeast to north and drops temps 5-10F in an hour,  and iceing the residue  and make travel very hazardous again in leftover new snowfall. Otherwise temps in the I84 corridor ~20-25F throughout the event.  Will add some graphics by 6AM on wherever the last page of the thread.  NOT a top 20 for NYC...best chance is MPO-POU axis in our forum.  This is my last topic update for this event. 

Will begin a storm accumulation obs  (snow/rain/sleet/damaging wind/coastal flooding) and nowcast topic by 6A to begin to be used once the snow begins-which I think will be between 1-4PM in our NJ/PA/w LI part of there forum. 

Graphics: my last on adding prestorm graphics.

NWS experimental severity index, the NWS snowfall forecast for our area as per 5A/16. 00z/16 EPS 10 to 1 snow ratio snowfall--i still think too high se edge and then snow ratios will magnify I84 corridor northwestward  NWS probabilistic 6+ and 18+. (Note NYC prob of 6+ is not that high). The 00z/16 SPCHREF gives us a better chance of exceeding 6" but the edges are always shaky. SPC SREF plumes for NYC. Please use all as options and may your expectations verify-just be realistic. 

 

Hey Walt thanks! I’m looking to head to Williamsport Pa, but good some recommendations for Lewisburg...where would you head if you were me to hit the jackpot right now?! You’re the best, thanks!!!

[LibertyBell]

2 hours ago, F5TornadoF5 said:

Upton now has Winter Storm Warnings for all of Suffolk County

 

URGENT - WINTER WEATHER MESSAGE
National Weather Service New York NY
347 AM EST Wed Dec 16 2020

NYZ078-080-179-162100-
/O.UPG.KOKX.WS.A.0001.201216T1900Z-201217T1800Z/
/O.EXA.KOKX.WS.W.0001.201216T1900Z-201217T1800Z/
Northwestern Suffolk-Southwestern Suffolk-Southern Nassau-
347 AM EST Wed Dec 16 2020

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

* WHAT...Heavy snow expected. Total snow accumulations of 6 to
  13 inches. Winds gusting as high as 50 mph.

* WHERE...Northwestern Suffolk, Southwestern Suffolk and
  Southern Nassau Counties.

* WHEN...From 2 PM this afternoon to 1 PM EST Thursday.

* IMPACTS...Travel could be very difficult to impossible. The
  hazardous conditions could impact the morning or evening
  commute. Gusty winds could bring down tree branches.

* ADDITIONAL INFORMATION...There is still some uncertainty with
  how much, if any mixing occurs Wednesday night. Snowfall amounts
  could be a bit lower than forecast along south coastal portions
  of the region if more mixing occurs.

 

URGENT - WINTER WEATHER MESSAGE
National Weather Service New York NY
347 AM EST Wed Dec 16 2020

NYZ079-162100-
/O.UPG.KOKX.WS.A.0001.201216T1900Z-201217T1800Z/
/O.EXA.KOKX.WS.W.0001.201216T1900Z-201217T1800Z/
Northeastern Suffolk-
347 AM EST Wed Dec 16 2020

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

* WHAT...Heavy snow expected. Total snow accumulations of 7 to
  10 inches. Winds gusting as high as 50 to 55 mph.

* WHERE...Northeastern Suffolk County.

* WHEN...From 2 PM this afternoon to 1 PM EST Thursday.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions could impact the morning or evening commute. Gusty
  winds could bring down tree branches.

* ADDITIONAL INFORMATION...There is still some uncertainty with
  how much, if any mixing occurs Wednesday night. If more mixing
  occurs, snowfall amounts will be lower.

 

URGENT - WINTER WEATHER MESSAGE
National Weather Service New York NY
347 AM EST Wed Dec 16 2020

NYZ081-162100-
/O.UPG.KOKX.WS.A.0001.201216T1900Z-201217T1800Z/
/O.EXA.KOKX.WS.W.0001.201216T1900Z-201217T1800Z/
Southeastern Suffolk-
347 AM EST Wed Dec 16 2020

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

* WHAT...Heavy snow expected. Total snow accumulations of 4 to 10
  inches. Winds gusting as high as 50 to 55 mph.

* WHERE...Southeastern Suffolk County.

* WHEN...From 2 PM this afternoon to 1 PM EST Thursday.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions could impact the morning or evening commute. Strong
  winds could cause tree damage.

* ADDITIONAL DETAILS...There is still some uncertainty with how
  much, if any mixing occurs Wednesday night. If more mixing
  occurs, snowfall amounts will be lower.

 

 

 

 

 

where is the one for Southern Nassau county and how much did they predict for there?  Thanks

[wdrag]

25 minutes ago, Wentzadelphia said:

Hey Walt thanks! I’m looking to head to Williamsport Pa, but good some recommendations for Lewisburg...where would you head if you were me to hit the jackpot right now?! You’re the best, thanks!!!

My thinking is north of I80 between MPO and IPT or I88 region to the northern Catskills for the NYS 20+.  You have to be safe wherever,  drifts and services including roads may shut down for a time there?  Also, check with others herein, NWS updates and TWC, of course updated modeling including the HRRR.  I'm doubtful of 20" here in Wantage... can happen but sleet is my concern between midnight and 4AM. You need to be in all powder, better snow rations but modeled 1.5" qpf. Again, this my opinion only and not gospel.  Definitely seek other opinions. Let's hope this works. 

[Northof78]

Dew points in low and mid single digits across the region....impressive airmass and very important.

[LibertyBell]

2 minutes ago, wdrag said:

My thinking is north of I80 between MPO and IPT or I88 region to the northern Catskills for the NYS 20+.  You have to be safe wherever,  drifts and services including roads may shut down for a time there?  Also, check with others herein, NWS updates and TWC, of course updated modeling including the HRRR.  I'm doubtful of 20" here in Wantage... can happen but sleet is my concern between midnight and 4AM. You need to be in all powder, better snow rations but modeled 1.5" qpf. Again, this my opinion only and not gospel.  Definitely seek other opinions. Let's hope this works. 

I really wish I was in my other home for this.....it's south of I-80 and just north of Allentown (halfway between ABE and MPO actually) but at 2,000 ft elevation it should stay all snow and get around 2 feet shouldn't it?

 

[LibertyBell]

1 hour ago, SnowGoose69 said:

This will likely be the biggest event of the winter I think.  I still expect La Niña background state eventually takes over.  It might not be til late January but I expect the majority of snow this winter still falls before 1/20

then you have other la nina winters like 55-56 or the one we had a few years ago which has the most snow in March....why were those different?

Even if this is a frontloaded winter, if we use 10-11 as an example we could get another HECS in the latter third of Jan, like around the 25th or so.

 

[HVSnowLover]

1 hour ago, SnowGoose69 said:

This will likely be the biggest event of the winter I think.  I still expect La Niña background state eventually takes over.  It might not be til late January but I expect the majority of snow this winter still falls before 1/20

That’s deflating especially coming off last winter but at least this event will produce way more snow than all of last winter did 

[Heisy]

12 minutes ago, LibertyBell said:

I really wish I was in my other home for this.....it's south of I-80 and just north of Allentown (halfway between ABE and MPO actually) but at 2,000 ft elevation it should stay all snow and get around 2 feet shouldn't it?

 

Sorry dumb question, but what do the stations MPO & IPT stand for?

[LibertyBell]

1 minute ago, Wentzadelphia said:

Sorry dumb question, but what do the stations MPO & IPT stand for?

MPO is Mount Pocono

KIPT is Williamsport

 

[SnoSki14]

13 minutes ago, Northof78 said:

Dew points in low and mid single digits across the region....impressive airmass and very important.

I'm at 8F dew so that's a good sign. Will see if the cold, dry high helps force the low more offshore as it moves north.