Discussion OBS for minor to possibly moderate impact winter storm interior 4A Tue - midnight Tue 12/2/25, may bring first measurable snow-sleet to coastal areas including NYC

[MANDA]

Thinking along the lines of 2-4" for my location and elevation.  Expect main / well traveled roads to have few if any issues as they will be heavily treated.  Side and back roads I would expect issues.  Not a bad start to the season and no matter what the first half of December looks to average solidly below normal.

[SnoSki14]

Probably some white rain at the onset, maybe even a little grass accumulation at best but will all turn to rain with temps near 40F. 

[MJO812]

7 minutes ago, SnoSki14 said:

Probably some white rain at the onset, maybe even a little grass accumulation at best but will all turn to rain with temps near 40F. 

Agree

All rain event for the coast

[SnowGoose69]

This probably is a snow event for NYC in January, even without a true high to the north but 12/2 is too early for that setup.  The temps are cold enough but the DPs are not due to the airmass in place

[SnoSki14]

6 minutes ago, SnowGoose69 said:

This probably is a snow event for NYC in January, even without a true high to the north but 12/2 is too early for that setup.  The temps are cold enough but the DPs are not due to the airmass in place

Agreed

[EastonSN+]

12 minutes ago, SnowGoose69 said:

This probably is a snow event for NYC in January, even without a true high to the north but 12/2 is too early for that setup.  The temps are cold enough but the DPs are not due to the airmass in place

I believe a good comparison would be December 5/6 2009. Offshore track resulting in hours of white rain. Areas just north and west had a moderate accumulation.

Actually a perfect benchmark track.

[EastonSN+]

Courtesy of Rays winter storm archive.

Again no accumulation for the coast.

[SnowGoose69]

16 minutes ago, EastonSN+ said:

I believe a good comparison would be December 5/6 2009. Offshore track resulting in hours of white rain. Areas just north and west had a moderate accumulation.

Actually a perfect benchmark track.

Forgot about that storm, that was one of the craziest cases I remember where the setup was almost perfect and it rained.  Many of us at that point felt we were headed for another 97-98

[EastonSN+]

1 minute ago, SnowGoose69 said:

Forgot about that storm, that was one of the craziest cases I remember where the setup was almost perfect and it rained.  Many of us at that point felt we were headed for another 97-98

I lived in Norwalk CT at the time and it snowed the entire time yet did not accumulate at all. 

[vegan_edible]

in albany until after new years. nam just said im getting 17 inches here. 

 

love getting nam'd

[MANDA]

21 minutes ago, EastonSN+ said:

Courtesy of Rays winter storm archive.

Again no accumulation for the coast.

Gotta love the old TWC maps!

[SnowGoose69]

17 minutes ago, vegan_edible said:

in albany until after new years. nam just said im getting 17 inches here. 

 

love getting nam'd

The RRFS looks reasonable with 2-4 or 3-5 up that way which is good news because it'll be the NAM replacement within a year.  

[NJwx85]

I could see a last minute cold tick that would bring accumulating snows to the coastal interior (West of the PIP and North of Rt 80) but as of now I think it’s mostly confined to the higher elevations of NW NJ and areas North and West of the 287/17/87 junction near Sloatsburg.

[the_other_guy]

Accuweather saying 1-3 for Westchester. Thats trending positive and I wouldnt write this off yet

[NJwx85]

2 minutes ago, the_other_guy said:

Accuweather saying 1-3 for Westchester. Thats trending positive and I wouldnt write this off yet

The 3” would be up near Yorktown Heights with less than an inch for Yonkers. Westchester is a tale of two worlds. The dividing line is often near Hastings on 87.

[snywx]

6 minutes ago, NJwx85 said:

I could see a last minute cold tick that would bring accumulating snows to the coastal interior (West of the PIP and North of Rt 80) but as of now I think it’s mostly confined to the higher elevations of NW NJ and areas North and West of the 287/17/87 junction near Sloatsburg.

Sloatsburg will prob be the transition line between accumulating snow & white rain. I’ve seen this story many times before. Rockland especially with these gradient storms is a snow hole. To get into the 5” + amounts you prob want to be in northern Sussex/w Passaic into Orange County. Watches should be going up for Orange/Sussex in the next update 

[the_other_guy]

19 minutes ago, NJwx85 said:

The 3” would be up near Yorktown Heights with less than an inch for Yonkers. Westchester is a tale of two worlds. The dividing line is often near Hastings on 87.

Thats me! I find one line at the Cross County and another at 287. There is also a North-South line just west of 95 for the coastal plain

[NorthShoreWx]

31 minutes ago, SnowGoose69 said:

The RRFS looks reasonable with 2-4 or 3-5 up that way which is good news because it'll be the NAM replacement within a year.  

12z NAM snow totals look reasonable for the coast. 

[wdrag]

ECAI is NO warmer than its 06z version... holding firm, in the range of noise whether any 5-10 mi slight south adjustment is worthy of significance.

What I aw was some slightly colder T/TD's compared to the 06z version...  Not sure whether NYC CP can hit 40... looks slightly colder upper 30s mostly rain but am not changing anything in previous threadline or I95 considerations.  

Maybe tomorrow I'll adjust to a moderate impact 6" event nw hills NJ-Poconos through interior se NYS w CT and interior MA. I think a low improbability wet snow ice tree limb breakage zone might be from maybe Easton PA to Passaic-Morris County-HPN-IJD line where temps hover at or below 32F all day. and IFFFF 4+" can accumulate on trees and wires.  Again low prob but depends on qpf and ptype. 

Still uncertainty on qpf amounts but strong fluxes with PRESFR as the low intensifies more than a mb/hr after 12z Tue, and so will have mixed ptypes both n/s of the general r/s line. mPing might be helpful. 

[Wxoutlooksblog]

Alot of precip issues determined by timing and whether low pressure holds back long enough that antecedent cold HP is gone or runs right into it since we do not yet have a purely southern storm track. Tuesday's was the one that had a shot but only if it started early enough. This probably the case now for the first two weeks of Dec.

WX/PT

[sussexcountyobs]

1 hour ago, snywx said:

Sloatsburg will prob be the transition line between accumulating snow & white rain. I’ve seen this story many times before. Rockland especially with these gradient storms is a snow hole. To get into the 5” + amounts you prob want to be in northern Sussex/w Passaic into Orange County. Watches should be going up for Orange/Sussex in the next update 

Yup. Sloatsburg, Tuxedo Park  From my years of commuting home that way every day, I agree. Stole my thunder about watches most likely going up this evening for my area.

[snywx]

2 minutes ago, sussexcountyobs said:

Yup. Sloatsburg, Tuxedo Park  From my years of commuting home that way every day, I agree. Stole my thunder about watches most likely going up this evening for my area.

We already have one up for orange. The first events of the season are always fun 

[Tatamy]

3 hours ago, MANDA said:

Thinking along the lines of 2-4" for my location and elevation.  Expect main / well traveled roads to have few if any issues as they will be heavily treated.  Side and back roads I would expect issues.  Not a bad start to the season and no matter what the first half of December looks to average solidly below normal.

I am thinking 1-2” for me before a mix/change to rain.  Definitely going for the under with this event by me with the models setting up the rain/snow line across my area.

[hudsonvalley21]

34 minutes ago, snywx said:

We already have one up for orange. The first events of the season are always fun 

URGENT - WINTER WEATHER MESSAGE National Weather Service New York NY 113 PM EST Sun Nov 30 2025 NYZ067-010700- /O.NEW.KOKX.WS.A.0003.251202T0900Z-251203T0300Z/ Orange- 113 PM EST Sun Nov 30 2025 ...WINTER STORM WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY EVENING... * WHAT...Heavy snow possible. Total snow accumulations between 4 and 7 inches possible. * WHERE...Orange County. * WHEN...From late Monday night through Tuesday evening. * IMPACTS...Travel could be very difficult. The hazardous conditions could impact the Tuesday morning and evening commutes. PRECAUTIONARY/PREPAREDNESS ACTIONS... Monitor the latest forecasts for updates on this situation. &&

 

[SnowGoose69]

1 minute ago, hudsonvalley21 said:

URGENT - WINTER WEATHER MESSAGE National Weather Service New York NY 113 PM EST Sun Nov 30 2025 NYZ067-010700- /O.NEW.KOKX.WS.A.0003.251202T0900Z-251203T0300Z/ Orange- 113 PM EST Sun Nov 30 2025 ...WINTER STORM WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY EVENING... * WHAT...Heavy snow possible. Total snow accumulations between 4 and 7 inches possible. * WHERE...Orange County. * WHEN...From late Monday night through Tuesday evening. * IMPACTS...Travel could be very difficult. The hazardous conditions could impact the Tuesday morning and evening commutes. PRECAUTIONARY/PREPAREDNESS ACTIONS... Monitor the latest forecasts for updates on this situation. &&

 

Might have put Putnam/Rockland in there but can always be added tomorrow 

[coastalplainsnowman]

2 hours ago, SnowGoose69 said:

Forgot about that storm, that was one of the craziest cases I remember where the setup was almost perfect and it rained.  Many of us at that point felt we were headed for another 97-98

Was confused for a moment because I distinctly remember a December 5th storm which crushed LI, noteworthy for how quickly it melted away.  But I see now that one was 2003.