OBS for NYC CP first measurable minor snowfall? 11A Fri 12/20-11A 12/21, embedded with surrounding area periodic minor accumulative snow

[snowman19]

8 hours ago, Allsnow said:

It’s the nam.

should be tossed until 24 hours out 

The NAM should have been discontinued years ago. I can’t believe NWS still bothers using it, it’s horrendous and hasn’t been updated in years. It’s as outdated and embarrassing as the NOGAPS

[MJO812]

Euro slightly more west

 

0z vs 6z

[snowman19]

3 minutes ago, MJO812 said:

Euro slightly more west

 

0z vs 6z

Noise. Nothing has changed since yesterday, very good model consensus (minus the awful NAM) on less than an inch for NYC and 1-2 for the NW suburbs, with the 2 inch amounts being up towards Orange, Passaic, Sussex. @donsutherland1

[wdrag]

Good Thursday morning... as others have mentioned,,similar to yesterday. 

Good Thursday morning everyone-Dec 19.

Similar to yesterday's post. A white Christmas is likely for a few spots in the immediate NYC metro (What do you want to use for immadiate = 10 miles??) from probably two minor events for NYC.

I95 corridor from Baltimore to Philly and NYC tomorrow night-Saturday morning: Probably minor travel impact at worst but a good chance that you'll see your first slight measurable snow of the season... if it occurs, probably less than 1", enough to make spirits brighter and possible slippery pavements Saturday morning.

Maps added are up through 4AM. The NWS model blender snow amount forecast for our area and also a statistical probability of more than 1" of snow and the NWS snowfall forecast before their 4AM issuance. I did add statistical probabilities for Central Park NY which are MUCH lower than what will happen along the NYS-NJ border. 

[IrishRob17]

10 minutes ago, snowman19 said:

Noise. Nothing has changed since yesterday, very good model consensus (minus the awful NAM) on less than an inch for NYC and 1-2 for the NW suburbs, with the 2 inch amounts being up towards Orange, Passaic, Sussex. @donsutherland1

I dont think anyone, including Anthony, is looking for or considering a major storm here, just looking for some mood snow to add to a festive time of the year for many. I know many out there want a blizzard or nothing, that’s fine, but I also know that some of us enjoy any snow that we can get, this time of year especially. 

[MJO812]

7 minutes ago, IrishRob17 said:

I dont think anyone, including Anthony, is looking for or considering a major storm here, just looking for some mood snow to add to a festive time of the year for many. I know many out there want a blizzard or nothing, that’s fine, but I also know that some of us enjoy any snow that we can get, this time of year especially. 

Any snow is good

[wdrag]

7 hours ago, RU848789 said:

@wdrag- for this event, the NBM has consistently shown higher snowfall amounts than all of the major models that most people look at regularly at places like Pivotal and TT (i.e., the Euro, GFS, CMC, UK, NAM, RDPS, etc.) and a decent amount more than the NWS is predicting.  I assume this means that the rest of the NBM models (there are many more as per the link below) are showing a decent amount more snowfall than the more commonly used models.  I've also always wondered if the NBM model obtains inputs from other models earlier than the public does, since the NBM output is available well before most of the model outputs are available.  Any insights on this (or from other folks who might know)?  Thanks.  

https://www.weather.gov/news/200318-nbm32#:~:text=The National Weather Service (NWS,their analysis of the data.

 

 

no insights right now...  bottom line... not sure what drives raw NWS snow forecasts, but the NBM I thought was supposed to be a first cut for the forecasters database?  Any NWS forecaster comment?  

 

One thing I do know... to respond to model trends, you've got to be nimble or you'll probably be in error--- though NOT always.   Takes ALOT of concentrated effort within 2 hours of issuance time (330A/330P).  If you're committed to available data at midnight-noon,  your briefings at 5A/5P could be missing something important? Again not always. 

[Tatamy]

This is this morning's AFD from Mt. Holly for the Friday through Saturday night period:

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
A deepening upper trough will be approaching the area to close the
week, which will be accompanied with several shortwaves embedded in
the flow. At the surface, low pressure originating over the High
Plains will traverse across the southern Great Lakes region and
approach our region by Friday afternoon. Forecast guidance has
trended a little deeper with the primary shortwave, so as the low
approaches, some precipitation is expected to develop and overspread
the area through the day Friday. At the same time, a secondary low
will be developing a couple hundred miles off the Mid-Atlantic coast
and deepen rapidly as it lifts northeast; enhanced by speed max
rounding base of the upper trough.

With the low offshore remaining in `close enough` proximity to the
area, it is likely that there will be some areas of mainly light
rain and snow across the area on Friday into Friday night as the
initial low transitions its energy to the offshore low. In addition,
some forecast guidance indicates the development of an inverted /
Norlun trough set-up on the northwest side of the offshore low. This
would enhance precipitation across portions of the area, however, it
is still uncertain where or if this feature is to even develop at
this time. For now, the best chance of observing accumulating snow
will be across the Lehigh Valley, northern New Jersey and in the
Poconos where temperatures will be cooler through the duration of
the event. Current forecast snow totals in these areas are for
between 1-2", locally up to 3". Light accumulations of a dusting up
to 1" are possible across the remainder of New Jersey, Pennsylvania
and northern Delaware as rain transitions to snow on Friday night as
temperatures cool below/near freezing. It should be noted though
that these type of inverted trough setups are notoriously difficult
to forecast as they can sometimes have localized heavier
precipitation amounts. If this occurs, some areas could "over
perform" and see snowfall amounts as high as 4 or 5 inches. Best
chances for this would be central into NW NJ, NE PA.

Precipitation will taper off from west to east by early Saturday
morning as the low exits toward Nova Scotia. The remainder of the
day Saturday will be blustery and cold with highs ranging from the
20s to low 30s north with mid to high 30s for highs near and
south/east of the I-95 corridor. Temperatures are expected to the
fall into the teens Saturday night an Arctic airmass begins to take
hold across the region.

[the_other_guy]

287 storm?? haha

[MJO812]

I doubt the Nam will be correct here unless other models start showing that solution. 

[MJO812]

[Bxstormwatcher360]

8 minutes ago, MJO812 said:

I doubt the Nam will be correct here unless other models start showing that solution. 

 

Just now, MJO812 said:

Im actually on board with this, also look at the clipper now,looks pretty robust atm,as it transfers energy,its gonna bomb. Somebody is going to get a good period of mod to heavy snow esp along coastal areas.

[Bxstormwatcher360]

Of note ,we are due for a clipper bomb around these parts. When i was younger clippers always enhanced appeaching the ocean,throwing back moisture. Now they barely get flurries across the app mountains stage right. 

[EastonSN+]

47 minutes ago, wdrag said:

no insights right now...  bottom line... not sure what drives raw NWS snow forecasts, but the NBM I thought was supposed to be a first cut for the forecasters database?  Any NWS forecaster comment?  

 

One thing I do know... to respond to model trends, you've got to be nimble or you'll probably be in error--- though NOT always.   Takes ALOT of concentrated effort within 2 hours of issuance time (330A/330P).  If you're committed to available data at midnight-noon,  your briefings at 5A/5P could be missing something important? Again not always. 

Not sure when the last measurable snow was for Central Park but this has a decent chance that's a win in my book.

[EastonSN+]

1 hour ago, MJO812 said:

Euro slightly more west

 

0z vs 6z

Great to see the models at least inching West. Recently we have been fearing the West trends on the models due to the southeast ridge however this time we have to root for it LOL.

One major difference between the last two Winters and this one is the lack of a deep RNA limiting the westward trends.

The RNA was so deep and anomalous the last two Winters it completely ruined decent blocking in the nao and AO regions.

[NEG NAO]

IMO anyone discounting any mesoscale model solution today ( the ones showing heavy snow or the ones showing next to nothing ) is taking a big chance........this storm is going to be a now casting event......with possibly a wide range in amounts region wide because of precip rates and precip type........

[BxEngine]

1 hour ago, IrishRob17 said:

I dont think anyone, including Anthony, is looking for or considering a major storm here, just looking for some mood snow to add to a festive time of the year for many. I know many out there want a blizzard or nothing, that’s fine, but I also know that some of us enjoy any snow that we can get, this time of year especially. 

Yup. If you dont want to discuss it, leave the damn thread to those who are discussing it. 

[the_other_guy]

it seems like Mount Holly is worried about mixing near  the coast at onset.

 

But then the models show possible heavy banding along the coast, which would negate that.

 

Thoughts?

[donsutherland1]

9 hours ago, RU848789 said:

@wdrag- for this event, the NBM has consistently shown higher snowfall amounts than all of the major models that most people look at regularly at places like Pivotal and TT (i.e., the Euro, GFS, CMC, UK, NAM, RDPS, etc.) and a decent amount more than the NWS is predicting.  I assume this means that the rest of the NBM models (there are many more as per the link below) are showing a decent amount more snowfall than the more commonly used models.  I've also always wondered if the NBM model obtains inputs from other models earlier than the public does, since the NBM output is available well before most of the model outputs are available.  Any insights on this (or from other folks who might know)?  Thanks.  

https://www.weather.gov/news/200318-nbm32#:~:text=The National Weather Service (NWS,their analysis of the data.

 

 

There are more models than what is shown on Pivotal, Tropical Tidbits, etc. Here's a link when the NBM was being developed: https://www.weather.gov/news/200318-nbm32

Some of the guidance updates hourly, hence the NBM also updates hourly.

[uofmiami]

7 minutes ago, donsutherland1 said:

There are more models than what is shown on Pivotal, Tropical Tidbits, etc. Here's a link when the NBM was being developed: https://www.weather.gov/news/200318-nbm32

Some of the guidance updates hourly, hence the NBM also updates hourly.

https://vlab.noaa.gov/web/mdl/nbm

Here’s a link to latest presentation of NBM v4.2:

https://vlab.noaa.gov/documents/6609493/7858320/2024-05-09_NBMv4.2.pdf/

[North and West]

It would be nice if I we can get a little snow for Christmas and maybe - just maybe - we can tone down the bickering for once, if only for Santa.

Other people’s happiness does not take away from your own. Happiness is not a zero sum game.


.

[Tatamy]

15 minutes ago, the_other_guy said:

it seems like Mount Holly is worried about mixing near  the coast at onset.

 

But then the models show possible heavy banding along the coast, which would negate that.

 

Thoughts?

The concern from Mt. Holly about mixing primarily relates to their southern NJ, SE PA, and Delaware zones.  For the remainder of their CWA the snowfall amounts will be related to the evolution of the IVT.  
 

As shown on numerous model runs it looks like the primary impacts from the IVT look to be from NYC on west.  As for the coastal depending on your model of choice most of its impacts will be east of the city and perhaps well east at that.  FWIW some of the models that show the coastal closer to the coast also have rain for a time in the coastal areas.  Many moving parts here.

[jm1220]

6 minutes ago, Tatamy said:

The concern from Mt. Holly about mixing primarily relates to their southern NJ, SE PA, and Delaware zones.  For the remainder of their CWA the snowfall amounts will be related to the evolution of the IVT.  
 

As shown on numerous model runs it looks like the primary impacts from the IVT look to be from NYC on west.  As for the coastal depending on your model of choice most of its impacts will be east of the city and perhaps well east at that.  FWIW some of the models that show the coastal closer to the coast also have rain for a time in the coastal areas.  Many moving parts here.

If the coastal really happens (still low chance), SE NJ would be hurt by onshore winds from still warm water. We’ve seen this with Dec coastal storms. If we’re just looking at the IVT, winds would likely be offshore so it would snow to the coast. I’m not jumping in at all with this coastal storm until the big boy models sign on. Seen way too many NAM head fakes. IMBY that’s probably my one chance at decent snow with this since the IVT seems to be highest probability over NJ. 

[TJW014]

it seems like Mount Holly is worried about mixing near  the coast at onset.
 
But then the models show possible heavy banding along the coast, which would negate that.
 
Thoughts?

Ocean's still 48-51 degrees. Give us the slightest amount onshore wind and it's going to wedge in a layer of warmer air. Heavier precip rates will negate that nose of warmth enought to keep it all snow to the surface.

Winds start out from the ENE, but once it swings north/northwest, we should see a complete changeover. Depends on how much moisture there is left to wring out.

[BoulderWX]

As expected NAM much different with the handling of the coastal on this run. IVT event still there but weaker. Would still take it and run..

through 39

[MJO812]

Just now, BoulderWX said:

As expected NAM much different with the handling of the coastal on this run. IVT event still there but weaker. Would still take it and run..

through 39

Not surprised it backed off since the other models weren't enthusiastic with a hugging coastal.

[EastonSN+]

Just now, BoulderWX said:

As expected NAM much different with the handling of the coastal on this run. IVT event still there but weaker. Would still take it and run..

through 39

Wrote it before but it's still comical how when we're fearing the Northwest trend it always happens yet when we need a Northwest trend it never happens lol. Only been happening for 2 years but feels like forever.

[LVblizzard]

Patiently waiting for someone to blame this NAM run on convective feedback or something. Happens with every storm threat when the models show something we don’t like.

[BoulderWX]

3k NAM - seems reasonable with more localized amounts, albeit low ones 

 

[NEG NAO]

One model 1 run BUT still shows a weak coastal in the benchmark track and energy from the clipper - its obvious as with many of these type events in mid December the place to be for more snow is from the Raritan River north and west in NJ which with the wind NE is a couple of degrees colder then points south and east - still plenty of time to go