Snowfall NYC subforum Jan 6 and OBS if needed

[pstar3182]

6 minutes ago, LibertyBell said:

Toms River is central NJ and considered the southern limit of our subforum (and the southern limit of our local TV stations.

I'm old, but rule of thumb was if Cablevison was giving you the NY Giants game and Philly on ch29 you're in South Jersey. 

[Snowlover11]

man this is painful, congratulations to the south.

[Franklin0529]

Nam coming north. The confluence over Maine is more relaxed

[Volcanic Winter]

This is such a frustratingly narrow stripe of accumulation, reminds of that first Jan 2022 that plastered ACY. 

[Brian5671]

6 minutes ago, Franklin0529 said:

Nam coming north. The confluence over Maine is more relaxed

still not much north of say 195 in NJ

[Volcanic Winter]

3 minutes ago, Brian5671 said:

still not much north of say 195 in NJ

I really don’t think even points south of 195 are getting much, at least based off what I’m looking at right now. 2-3 inches here in TR is probably the best case scenario, which is nice - sure. 

Was just looking over the latest runs and it’s like ACY lat -> west. And I’m hoping the north edge isn’t like that early Jan 2022 system which was mostly virga. I got absolutely nothing while ACY got over a foot, that was brutal. 

[Franklin0529]

4 minutes ago, Brian5671 said:

still not much north of say 195 in NJ

Still 72 hrs away. How many times have we been in the bullseye just for it to shift way north an hammer Boston? I still think the city south gets 2-4" out of this

[Franklin0529]

Nam Poppin a 992 low right off Ocean City. If we can get that coastal goin we're in good shape. Plenty of time. Storm just getting to the West Coast tonight. Better sampling starting now

[Volcanic Winter]

1 hour ago, LibertyBell said:

Toms River is central NJ and considered the southern limit of our subforum (and the southern limit of our local TV stations.)

Yup, sorry not going to clog this thread up with any further discussion on this. Just noting that factually TR is definitely still part of the suburban metro of NYC (which we think of as CNJ -> N), but culturally it’s much more debatable which I acknowledge. It’s probably colored by the fact that I worked for 15 years in the immediate metro and grew up in Middlesex and inland Monmouth. 

But yeah, like anything else people have differing opinions which is fine. 

Back to Schrodinger’s snowstorm. It’s there, and it isn’t! 

[jm1220]

18 minutes ago, Brian5671 said:

still not much north of say 195 in NJ

The strong PV lobe just N of Vermont needs to leave or weaken significantly. It's a great run for DC over to ACY but sucks north of there because that PV lobe presses the confluence hammer down just as our storm approaches. As long as that's there anywhere near that strong we're screwed up here. Period. 

[Allsnow]

Icon way south 

 

edit: gets a inch up to nyc but initially it looked south of 12z

[wxman]

I saw three flakes just now.

[forkyfork]

13 minutes ago, Allsnow said:

Icon way south 

 

edit: gets a inch up to nyc but initially it looked south of 12z

there's some constructive interference with the pv lobe so precip is able to lift north as the storm departs

[dmillz25]

8 minutes ago, forkyfork said:

there's some constructive interference with the pv lobe so precip is able to lift north as the storm departs

NAM and RGEM showed this too

[Brian5671]

yippee some flurries at the end!

[Allsnow]

12 minutes ago, forkyfork said:

there's some constructive interference with the pv lobe so precip is able to lift north as the storm departs

Thanks 

[MJO812]

Gfs is a tick north

[BoulderWX]

1 minute ago, MJO812 said:

Gfs is a tick north

Typical run to run noise but same idea. 

[MJO812]

2 minutes ago, BoulderWX said:

Typical run to run noise but same idea. 

Not sure. Other forums think it's close to a phase. Worth watching. 

[Brian5671]

1 minute ago, MJO812 said:

Not sure. Other forums think it's close to a phase. Worth watching. 

A phase with what?   The low zips east off Norfolk VA

[dmillz25]

1 minute ago, Brian5671 said:

A phase with what?   The low zips east off Norfolk VA

There a lobe near Wisconsin that tries to phase in last min

[MJO812]

Just now, dmillz25 said:

There a lobe near Wisconsin that tries to phase in last min

It was close. That's why it came slightly more north. We should watch that . Nothing wrong with 1-3 inches if we do get that. 

[MJO812]

[Franklin0529]

.4 qpf line almost reaches the city. Couple more ticks like that is certainly doable 

[BoulderWX]

Need to also realize that on the northern fringes there is going to be a lot of subsidence and dry air to overcome so would keep expectations in check riding the northern edge. 

[North and West]

That looks like it would pretty up my area, which is the only thing we care about, amirite?!




.

[NEG NAO]

37 minutes ago, MJO812 said:

Gfs is a tick north

Read the Mt. Holly Afternoon discussion they think the precip shield is too far south and the shift south in the models was overdone

[RU848789]

Surprised at this, but more hopeful now, but also a bit skeptical...we'll see soon...see the part in bold, in particular for amounts, but to summarize here: 1-2" N of 80, 2-4" from 80 down to 276/195, 4-6" south of 276/195 with lollipops to 6-8 where the best banding sets up in SEPA/SNJ.  I could certainly live with this.  Edit: here's the NWS map for NWS-Philly and parts of adjacent offices.  Nice.  

Area Forecast Discussion
National Weather Service Mount Holly NJ
335 PM EST Fri Jan 3 2025

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...

Our attention then turns to the winter storm potential that will
impact the Mid-Atlantic region late Sunday night through Monday,
possibly lingering into Monday night. A potent shortwave ejecting
out of the Rocky Mountain region will develop into a closed low as
it slides across the Central Plains. This closed low will undergo
cyclogenesis and lead to a surface low developing while tracking
through the Central US on Sunday night. The surface low will
continue to track due east crossing somewhere between the southern
Delmarva and eastern North Carolina by Monday afternoon.

The biggest challenge that still persists at this time is with
regard to the track of the surface low and where it will be as it
crosses through the area. While the majority of ensemble guidance
has shown a southern shift over the past 12-24 hours with QPF,
looking at the overall atmosphere aloft including jet dynamics and
mesoscale features, it seems that the overall consensus of the track
seems to be too far south. Depending on the strength of the system
as it approaches and confluence that lingers over the Northeast US,
will simply determine how far north the snow shield reaches. Have
started to see some waffling back and forth with the 12Z guidance,
so don`t completely buy the entire southern shift. Unfortunately,
there is still a lot of uncertainty amongst global guidance, where
the greatest potential for higher-level impacts remains over the
southern-half of the forecast area.

With all this in mind, the forecast this afternoon features a
solution that incorporates warning level snowfall for areas around
Philadelphia and points south. The highest snowfall amounts will end
up being located within a frontogenetic band where SLRs will be
locally higher under an area of enhanced snowfall. The confidence is
rather low on where this FGEN band will set-up over the region
though. Based on latest 700-850 mb frontogenesis progs, the greatest
likelihood will be somewhere between the Philly metro and central
Delaware. In fact, some of the hi-res guidance that has come in this
afternoon shows a warm nose between 850-925 mb that creeps northward
during the day on Monday into portions of the Eastern Shore of
Maryland and southern Delaware. This would result in some potential
mixing issues in the form of sleet and/or freezing rain which will
drastically undercut snow totals, with the heaviest snow totals
located just north of the mixing line.

Upon discussion with neighboring offices and given the overall
uncertainty, have opted to not issue any Winter Weather headlines
with this forecast package. In terms of snowfall amounts, our
initial forecast is for a 4-6 inch snowfall event for areas on a
line from I-76 to I-195 and points south, including the Philadelphia
metro. Within this area, will be a localized maxima of 6-8+ inches
depending on where the frontogenetic banding sets up. Between the
I-80 and I-76/I-195 corridor, expecting totals in the 2-4 inch
range with totals less than 2 inches to the north of I-80. There
will be a sharp northern gradient to the snowfall due to confluence
and dry air off to the north, so some of these totals may be slightly
too high.

[LibertyBell]

3 minutes ago, RU848789 said:

Surprised at this, but more hopeful now, but also a bit skeptical...we'll see soon...see the part in bold, in particular for amounts, but to summarize here: 1-2" N of 80, 2-4" from 80 down to 276/195, 4-6" south of 276/195 with lollipops to 6-8 where the best banding sets up in SEPA/SNJ.  I could certainly live with this.  

Area Forecast Discussion
National Weather Service Mount Holly NJ
335 PM EST Fri Jan 3 2025

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...

Our attention then turns to the winter storm potential that will
impact the Mid-Atlantic region late Sunday night through Monday,
possibly lingering into Monday night. A potent shortwave ejecting
out of the Rocky Mountain region will develop into a closed low as
it slides across the Central Plains. This closed low will undergo
cyclogenesis and lead to a surface low developing while tracking
through the Central US on Sunday night. The surface low will
continue to track due east crossing somewhere between the southern
Delmarva and eastern North Carolina by Monday afternoon.

The biggest challenge that still persists at this time is with
regard to the track of the surface low and where it will be as it
crosses through the area. While the majority of ensemble guidance
has shown a southern shift over the past 12-24 hours with QPF,
looking at the overall atmosphere aloft including jet dynamics and
mesoscale features, it seems that the overall consensus of the track
seems to be too far south. Depending on the strength of the system
as it approaches and confluence that lingers over the Northeast US,
will simply determine how far north the snow shield reaches. Have
started to see some waffling back and forth with the 12Z guidance,
so don`t completely buy the entire southern shift. Unfortunately,
there is still a lot of uncertainty amongst global guidance, where
the greatest potential for higher-level impacts remains over the
southern-half of the forecast area.

With all this in mind, the forecast this afternoon features a
solution that incorporates warning level snowfall for areas around
Philadelphia and points south. The highest snowfall amounts will end
up being located within a frontogenetic band where SLRs will be
locally higher under an area of enhanced snowfall. The confidence is
rather low on where this FGEN band will set-up over the region
though. Based on latest 700-850 mb frontogenesis progs, the greatest
likelihood will be somewhere between the Philly metro and central
Delaware. In fact, some of the hi-res guidance that has come in this
afternoon shows a warm nose between 850-925 mb that creeps northward
during the day on Monday into portions of the Eastern Shore of
Maryland and southern Delaware. This would result in some potential
mixing issues in the form of sleet and/or freezing rain which will
drastically undercut snow totals, with the heaviest snow totals
located just north of the mixing line.

Upon discussion with neighboring offices and given the overall
uncertainty, have opted to not issue any Winter Weather headlines
with this forecast package. In terms of snowfall amounts, our
initial forecast is for a 4-6 inch snowfall event for areas on a
line from I-76 to I-195 and points south, including the Philadelphia
metro. Within this area, will be a localized maxima of 6-8+ inches
depending on where the frontogenetic banding sets up. Between the
I-80 and I-76/I-195 corridor, expecting totals in the 2-4 inch
range with totals less than 2 inches to the north of I-80. There
will be a sharp northern gradient to the snowfall due to confluence
and dry air off to the north, so some of these totals may be slightly
too high.

2-4 inches sounds interesting south of I-80 although it's also worth noting that the more east you go, the further south the snow shield will be,

[MJO812]

Gefs