discussion on 2024-01-02

000
FXUS61 KOKX 030250
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
950 PM EST Tue Jan 2 2024

.SYNOPSIS...
High pressure builds over the Southeast through midweek, sliding
offshore Wednesday night. A cold front moves through Thursday as low
pressure passes well offshore. High pressure starts to build in Thursday
night and remains in control into Saturday. A storm system impacts
the area Saturday night into Sunday with another system for the
middle of next week.

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
-- Changed Discussion --The forecast remains on track. For the most part hourly
temperatures and dewpoints did not have to be adjusted much with
this update as observations are matching up nicely with the near
term forecast.

Tranquil conditions persist through tonight as shortwave ridging
builds in aloft and surface high pressure noses in from the
south and west.

Mainly clear skies prevail through the first half of the night
and with a light west wind, temperatures are already getting
below NBM guidance. Stuck with more of a MAV/MET blend to
capture this, with forecast lows ranging from the mid 30s in the
urban metro, to the low 20s across the interior and LI Pine
Barrens. The ridge axis shifts east overnight ahead of the next
shortwave, allowing high and mid level clouds to increase late.-- End Changed Discussion --

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
Surface high pressure over the Southeast shifts offshore
Wednesday ahead of an approaching shortwave trough. Associated
surface low pressure forms off the Mid Atlantic coast Thursday
and strengthens well east of the area. To the west, a cold
front will swing through our area Thursday, with high pressure
returning behind it.

The fropa appears mostly dry Thursday as the deepening wave of
low pressure tracks well offshore. A few spotty showers will be
possible across eastern areas, mainly the LI forks and SE CT.
Marginal temperatures may allow any precipitation to fall as
snow, or a rain/snow mix, in the morning hours. The boundary
layer likely warms enough by afternoon that any remaining
precipitation would fall as rain. In any case, QPF would be
light, if it occurs at all, perhaps a few hundredths east.

A 1030 mb high begins to build in Thursday night behind the
low. There will be a brief period late Thursday through Thursday
night where a tight pressure gradient between the offshore low
and building high may allow NW gusts to approach 30 mph.

Temperatures will be close to seasonal norms, highs generally
in the low to mid 40s, and lows in 20s and 30s.

.LONG TERM /FRIDAY THROUGH TUESDAY/...
*Key Points*

* A coastal storm is expected to impact the area Saturday night into
Sunday. Too early to be specific with potential snow amounts and
precipitation types. Wind and coastal flooding impacts will be
possible as well.

* Another area of low pressure for the middle of next week may bring
wind and flooding impacts.

Deep-layered ridging on Friday will bring dry and sunny conditions
to the area with high temperatures slightly below normal. High
pressure then lingers long enough to keep us dry through at least
Saturday morning.

Deterministic and ensemble global guidance continue to agree on an
area of low pressure that will likely be close enough to us to bring
impacts. At this time, there`s still upwards of a 300 mile spread in
the track of the storm, but there`s growing confidence that the
storm center would pass to our SE, perhaps near the 40N/70W
benchmark during Sunday morning. Sensitivity appears to lie in
shortwave energy ejecting downstream from an Aleutians low, then
rotating around a southern US upper low. This interaction might take
another day or two to become better-resolved by the RAOB network.

Enough confidence at this point to go with categorical PoPs for
Saturday night, but precip may begin by the end of Saturday
afternoon. Most of the precip is likely done by the middle of
Sunday morning. Too early to get overly specific with precip types
and accumulations, but with that said, there`s a moderate
probability of at least a plowable snow occurring across interior
areas with a lower (but growing) probability at the coast. As for
winds, there`s the potential of marginal advisory-level winds for
coastal areas during Saturday night. There may also be minor
coastal/shoreline impacts, including scattered dune erosion.

Another area of low pressure is then progged to pass through the
eastern Great Lakes Region on Tuesday with perhaps a secondary or
triple-point low passing passing nearby here later on. Main threats
with this storm would be strong winds (with a tighter pressure
gradient and stronger low level jet this time around), and
freshwater flooding. Flooding threat would be greatest over the
interior sections where, even outside of the amount of rain that
falls, an existing snowpack may be present and rapidly melt on top
of already-saturated soils.

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --High pres remains centered SW of the region thru Wed morning. A
trough of low pressure preceding a cold front approaches Wed evening.

Mainly VFR through the day Wednesday. The exception is KSWF where
BKN MVFR ceilings are expected to prevail by midday on Wed. MVFR
ceilings start to become more likely for the 30 hr city terminals
towards 0z Thu. MVFR ceilings may prevail sooner but confidence
of occurrence during the day Wed remains low, especially for the
city and more eastern terminals.

The winds will be mainly out of the W at 5 to 8 kt overnight,
and below 5 kt for the non-city terminals. The winds then
increase to around 10 kt at most terminals during the day Wed,
then decrease to closer to 5 kt Wed evening.

...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

No unscheduled amendments expected through tonight. Amendments may
be needed Wed afternoon for possible MVFR ceilings.

OUTLOOK FOR 00Z THURSDAY THROUGH SUNDAY...

Wednesday night: MVFR to VFR, with MVFR more likely for the western
most terminals.

Thursday: Chance of MVFR or lower cond in rain/snow showers early,
improving to VFR. NW winds 10-15G20-25kt.

Thursday night: VFR. NW winds 10-15G20-25kt.

Friday: VFR. NW winds G20kt possible for the AM push.

Saturday: VFR becoming IFR or lower Sat ngt in snow and/or rain.
Increasing E/NE winds.

Sunday: Rain/snow ending as snow. IFR or lower possible. Winds
becoming N.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --

.MARINE...
Quiet conditions over the waters through Wednesday night. Winds
increase late Thursday as low pressure passes well offshore and
high pressure builds in from the west. Small Craft Advisories
look likely on all waters Thursday afternoon through Thursday
night with 25 to 30 kt wind gusts. Wind gusts on the ocean
waters may briefly approach or exceed 35 kt. Ocean seas will
also likely reach 5 to 6 ft.

Winds should begin weakening on Friday, but some lingering 25 kt
gusts are possible on the ocean. Seas should subside below 5 ft by
Friday afternoon. Conditions are then expected to be below SCA
levels on Saturday.

A storm system impacting the waters Saturday night into Sunday will
bring a chance of gales across all waters during the this period.
HWO mention of this potential continues. Ocean seas during this time
will probably build over 10 ft.

.HYDROLOGY...
A liquid-equivalent 0.75 to 1.50 inches of precipitation is
anticipated from late Saturday afternoon through Sunday morning.
Since some of this may be in the form of snow, impacts may be
minimal.

A greater flooding threat (especially rivers) may exist starting
next Tuesday. This will partially depend on what materializes this
weekend. Regardless, soils will remain nearly saturated leading up
to the event.

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

SYNOPSIS...JC/DR
NEAR TERM...JE/DR
SHORT TERM...DR
LONG TERM...JC
AVIATION...JE
MARINE...JC/DR
HYDROLOGY...JC/DR