091
FXUS61 KOKX 291817
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
217 PM EDT Sat Jun 29 2024

.SYNOPSIS...
A warm front moves across the region this afternoon and the north
of the region going into this evening. A cold front approaches
tonight into Sunday and moves across the area Sunday afternoon
into Sunday night. High pressure then follows Monday and lasts
into Wednesday. A weakening cold front may impact the area
Wednesday night. A more robust frontal system may impact the
area from late day Thursday into Friday.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Forecast remains on track this afternoon.

Chances for showers slowly increase into the afternoon north
and west of the NYC metro as the warm front begins to lift
through the area. Forcing is generally weak and there is limited
instability aloft. A consensus of the latest CAMS indicates a
line of showers with embedded thunderstorms should approach from
the west this evening. Some of the CAMs actually dissipate the
line as it enters the area while others slowly weaken it. The
forcing remains weak and instability is elevated. The warm front
should continue lifting north through the rest of tonight, but
a pre-frontal trough settles nearby early Sunday morning. Some
weak energy aloft may be enough to regenerate showers and a few
thunderstorms early in the morning, with the higher probability
across the eastern two thirds of the region.

Not anticipating a severe thunderstorm threat through early
Sunday morning given the weak forcing and little to no surface
based instability. However, deep subtropical moisture will be
in place with PWATs approaching 2-2.25 inches on average. This
will lead to the potential of locally heavy downpours. Minor
flooding is the main threat as the activity should have enough
forward speed, but cannot completely rule out a localized flash
flood occurrence tonight.

Strengthening onshore flow will lead to wind gusts 20-25 mph,
especially near the coast this afternoon into this evening.
There will also be a good deal of cloud cover so temperatures
will not rise much above the upper 70s for most with lower 80s
in NE NJ. It will become increasingly more humid as dew points
rise into the upper 60s by this afternoon and evening and then
into the lower 70s tonight.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
Main concern for Sunday will be the potential for severe
thunderstorms and locally heavy downpours, mainly in the
afternoon and evening.

There remains potential for some showers and a few thunderstorms
to be ongoing to start the day along and ahead of the pre-
frontal trough. This looks to align itself closest to the coast.
Some of the guidance pushes any of this activity to our east
shortly after 12z. The uncertainty with how any morning
convection evolves may ultimately impact the environment in the
afternoon and evening, especially if lingering clouds are slow
to clear. The pre-frontal trough does look to remain near Long
Island/Southern CT with the actual cold front to the northwest
into the early afternoon. The cold front should then make its
way from northwest to southeast across the area in the evening.

Deep subtropical moisture should remain in place ahead of the
cold front, although there may be a slight decrease behind the
pre- frontal trough. Overall, PWATs look to average around
2-2.25 inches, so the threat for locally heavy downpours
continues. The flow aloft will be strengthening through the day
as the middle and upper level shortwave moves over New England.
These increasing winds bring bulk shear values to 40-45 kt.
MLCAPEs may range from around 1500 J/kg near the coast and
upwards of 2500-3000 J/kg inland. The flow is mainly
unidirectional, but there may be some backing of the low level
flow immediately ahead of the cold front.

SPC has continued to place the entire region in a slight risk
for severe thunderstorms Sunday afternoon and evening. The
main severe thunderstorm threat appears to be from damaging wind
gusts. Some hail is possible, especially if the higher CAPE
values aloft materialize. There is also a risk for an isolated
tornado.

The threat for flash flooding remains low and localized, with
minor urban/poor drainage flooding the main concern.

The other story for Sunday will be brief heat and humidity.
Despite varying levels of cloud cover, there should be enough
warming to push temperatures into the upper 80s to around 90 for
the NYC metro and NE NJ with middle to upper 80s most
elsewhere. These temperatures combined with dew points in the
lower 70s will yield heat indices in the low 90s for much of the
area, with NYC metro and NE NJ in the middle to upper 90s.

The cold front pushes offshore Sunday evening bringing an end to
the severe thunderstorm threat. Drier and cooler air will work
in behind the front and skies will clear through the night. The
upper trough axis moves across Monday morning with high
pressure at the surface and aloft beginning to build in from the
west Monday afternoon. Highs will be near seasonable levels in
the upper 70s and lower 80s.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
High pressure sfc and aloft will be mostly in control through
mid week, with a warm front passing to the north Tue night into
Wed. A weakening cold front may touch off a shower or tstm Wed
night, but a more important frontal system as heights fall aloft
and shortwave energy streams eastward from the Plains states,
with chances for more widespread showers/tstms during that time.


Temps will be near to slightly above normal during of of that
time, with highs mostly in the 80s. Thu should be warmer, with
highers in the lower 90s in the NYC metro area and NE NJ, and
heat index values in the mid/upper 90s in those areas and parts
of the Hudson Valley and nearby SW CT.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
A warm front approaches this afternoon and moves through this
evening. A pre-frontal trough approaches tonight and settles nearby
on Sunday.

VFR conditions prevail through the remainder of the day. Cigs lower
to MVFR this evening towards 22 to 00z, and then to IFR at most
terminals for the overnight. LIFR conds with tstms possible mainly
after midnight, with any LIFT conds likely confined to KHPN, KISP,
KGON, and potentially KJFK.

Winds will be SE and S this afternoon, with most terminals S for
this evening. Winds at most coastal terminals gust to 20 to 25 kt
this afternoon, with a few gusts closer to 30 kt at KLGA and KJFK.
The winds are expected to become more SW Sunday morning.

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

Timing of sub VFR conditions returning this evening may be off by a
couple of hours. Amendments may be needed with changing flight cats
this evening and through the overnight, and into Sunday morning.


OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY...

Sunday afternoon and evening: VFR gives way to a period of MVFR and
possible IFR cond with TSRA containing gusty winds. VFR returns for
Sunday night.

Monday through Wednesday: VFR.

Thursday: Mainly VFR, with possible sub VFR later in the day and at
night in possible SHRA or TSRA.

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

&&

.MARINE...
S-SE winds increase today as a warm front lists north of the
waters. Near shore gusts to around 25 kt are likely this
afternoon into this evening and will be followed by ocean seas
building to 5-6 ft this evening into tonight. SCA for the ocean
and South Shore Bays started at 2 pm this afternoon and goes
through early Sunday evening. The most widespread wind gusts
25- 30 kt looks to occur tonight into Sunday morning with winds
diminishing below SCA levels Sunday afternoon and evening. There
is a threat for severe thunderstorms which could locally
increase winds Sunday afternoon and evening. Elevated seas
continue into Sunday evening. The passage of the cold front
Sunday evening will bring weakening winds and subsiding seas
into Monday morning.

Conditions will then remain below SCA levels Monday through
Wednesday. Late day winds in the NY Bight area just E of Sandy
Hook could gust close to 25 kt both Wed and Thu afternoons.

&&

.HYDROLOGY...
A round of showers and thunderstorms are expected tonight
into early Sunday morning with potential of locally heavy
downpours. Another round of showers and thunderstorms will
accompany a cold front passage Sunday afternoon and evening
with a continued chance for locally heavy downpours. The most
likely threat will be from minor urban and poor drainage
flooding. The risk for flash flooding is low and localized.

Locally heavy rainfall may be possible Thu night into Fri with a
passing frontal system.

&&

.TIDES/COASTAL FLOODING...
The rip current risk this morning is moderate, but quickly
increases to high this afternoon and evening with strengthening SE
winds and building seas.

The high risk continues into Sunday with swells of 5-6 ft and 7
second period.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents through Sunday evening for NYZ075-080-
     081-178-179.
NJ...None.
MARINE...Small Craft Advisory until 8 PM EDT Sunday for ANZ345-350-353-
     355.

&&

$$

SYNOPSIS...BG/DS
NEAR TERM...JM/DS
SHORT TERM...DS
LONG TERM...BG
AVIATION...JE
MARINE...BG/DS/JM
HYDROLOGY...BG/DS
TIDES/COASTAL FLOODING...