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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KOKX 052033
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
333 PM EST Tue Dec 5 2023

.SYNOPSIS...
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Weak high pressure gives way tonight to a developing low pressure
that develops well to the south of the area on Wednesday. High
pressure noses in from the south on Thursday as a warm front
approaches from the west. The warm front will lift north of the
region Friday into Saturday. A strong frontal system approaches
from the west Sunday with its associated cold front moving
across Sunday night. High pressure returns for early next week.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
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Weak mid-level ridging over the area gives way to an incoming
shortwave embedded in a large-scale trough approaching from the west
tonight and into Wednesday. The energy associated with this
shortwave is forcing a weak surface low over the southern Great
Lakes. At this time, this is resulting in very light snowfall over
much of western Pennsylvania. As the moisture associated with this
weak disturbance approaches the area tonight, much of the weak
precipitation is expected to dissipate as it runs into drier air
over the area. That being said, left a slight chance of snow
showers, possibly mixed with rain showers for coastal areas, for
much of the area tonight. Otherwise, overcast skies are anticipated
and lows tonight will be in the middle to upper 20s for outlying
areas with low temperatures in the low to middle 30s for the NYC
metro.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
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As the shortwave energy approaches the East Coast on Wednesday,
cyclogenesis occurs off of the Carolina coast. The area will remain
well to the north of the low and the most likely sensible weather
from the deepening of the low will be an increase in winds into the
afternoon and evening on Wednesday.

As the energy from the weak surface wave over the Ohio Valley
transfers to the developing coastal low, low level moisture may
increase a bit. Increased moisture combined with cooler temperatures
aloft due to the placement under an upper level trough, may result
in the development of some instability showers during the day on
Wednesday, though much of these should be confined to the eastern
portion of the area. High temperatures on Wednesday will only be in
the upper 30s to near 40 for much of the area so any of these
showers that develop will have a chance of being snow showers. The
earlier in the day they develop, the high the chance at seeing snow,
but even if surface temperatures are above freezing into Wednesday,
cool temperatures aloft may support the occurrence of at least a mix
with snow in any shower that develops.

Any showers end Wednesday afternoon and into Wednesday night with
skies clearing in the wake of the departing low. A brisk NW wind
advects in cold air such that low temperatures Wednesday night into
Thursday morning will be in the 20s for much of the area. Some
outlying spots may drop into the upper teens.
-- End Changed Discussion --

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
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Stayed fairly close to the NBM throughout the period. A quasi-zonal
flow to begin the period on Thursday becomes increasingly amplified
into the weekend. A trough over the Northern Rockies will amplify as
it progresses east. This will be the system that impacts our sensible
weather late in the weekend. Afterwards, high pressure should return
into next week.

A warm front will reside just west of the area and nearby into
Thursday. This will bring more in the way of clouds into the area,
especially further west. A cP air mass will stick around through
Thursday which should keep the area dry despite more in the way of
clouds. Temperatures will average a good 5 degrees or so below
normal before the air mass begins to push off the coast Thursday
night. On Friday the warm front is expected to progress east and
lift north of the area. This will lead to an increasing southerly
component to the wind direction. An eventual SW flow will get
temperatures a few degrees above normal by Friday afternoon with a
fair amount of sun. Towards Saturday the warm front should get well
north of the area, and thus a mild south to southwest flow will
prevail. Warm advection should promote temperatures at 850 mb to get
to around 8 to 10 C. Therefore temperatures should get into the
middle 50s, a good 10 degrees above normal to begin the weekend. It
is possible that temperatures could get even warmer than currently
progged, but NBM members were not straying far from the mean, thus
did not get more aggressive with daytime maxes on Saturday but could
easily see it get another 3 degrees or so warmer than currently
progged.

The trough then swings into the east for Sunday and Sunday night.
There is some spread among the ensembles with the timing, but
confidence remains high for a strong frontal system to work through
later in the day Sunday into early Monday AM. Other than a few
showers Sunday morning, most of the morning may remain dry. For
Sunday afternoon look for rain to develop from W-SW to E-NE as a
good conveyor belt of moisture begins to work up along the coastal
plain. Despite cloud cover and rain look for temperatures to top out
close to 60. The steadiest rain based on the latest consensus
guidance looks to take place Sunday night, with much of the rain
falling the first half of Sunday night. Standardized anomalies for
mean IVT from the ECMWF and the NAEFS run at +3 to +4, with PWATs
standardized anomalies at around +3. NBM probabilities of greater
than 2 inches of rain get to around 30 percent for NW portions of
the area, and probabilities of greater than 1 inch get to around 70
percent for NW sections. Therefore rainfall amounts of 1 to 1.5
inches has a good chance for late Sunday / early Mon AM. Winds
should get rather gusty late in the day Sunday through Monday
morning. Winds out of the south with gusts of around 40 to 45 mph
are possible, with the strongest winds likely Sunday evening /
night. The cold front should clear the area towards daybreak on
Monday with the winds switching to the W. The pressure gradient
should weaken gradually during the day Monday. Look for Monday to
dry out with blustery and cooler conditions. Seasonable temperatures
and dry conditions will be in place for the remainder of the
period.
-- End Changed Discussion --

&&

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
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High pressure remains in control.

VFR. A slight chance of a flurry or light snow shower mainly east of
the city terminals after midnight through Wednesday morning.

NW-N winds under 10kt, veering more N this evening. Winds for the
non-city terminals and KTEB diminish to light and variable this
evening. NNW winds increase Wednesday morning with gusts around 20kt
during the afternoon.

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

No unscheduled amendments expected.

OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...

Wednesday PM: VFR. NNW gusts near 20kt for the afternoon into
the night, mainly at coastal terminals.

Thursday-Saturday: VFR.

Sunday: Mainly VFR in the morning with chc S gusts 20-25kt.
Rain/MVFR/IFR/LLWS mainly in the afternoon and night with a chance
of S-SW gusts 30-40kt.

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

&&

.MARINE...
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Sub-SCA conditions are expected on all waters through Wednesday
morning. By Wednesday afternoon, winds increase to marginal SCA
criteria with gusts to 25 kt on the ocean zones as the pressure
gradient tightens over the area with the development of a coastal low
well to the south. SCA gusts on the ocean zones likely continues
into the first half of Wednesday night before falling below 25 kt by
Thursday morning.

Sub-SCA conditions are expected Thursday through Saturday night with
ocean seas averaging close to 3 ft. Winds and seas should ramp up
quickly during Sunday with small craft conditions quickly going to
Gales in all likelihood by later in the day.  Solid gales are
expected across all waters Sunday night, with gales likely
lingering into Monday morning for the eastern waters.
-- End Changed Discussion --

&&

.HYDROLOGY...
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An inch to an inch and a half of rain is possible Sunday and Sunday
night. At this time only minor and localized hydrologic impacts
appear possible, though confidence remains low this far out.
-- End Changed Discussion --

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 1 PM Wednesday to 4 AM EST Thursday
     for ANZ350-353-355.
-- End Changed Discussion --

&&

$$

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