789
FXUS61 KOKX 290756
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
356 AM EDT Sat Jun 29 2024

.SYNOPSIS...
A warm front moves north of the area this afternoon and
evening. A cold front then approaches tonight with its
associated pre-frontal trough moving over the area early Sunday
morning. The cold front will then move across on Sunday afternoon
and evening. High pressure then follows Monday and lasts into
Wednesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
High pressure continues to move offshore early this morning
with warm advection beginning to take place. Low clouds should
begin to increase in association with the warm advection and as
a warm front begins approaching this morning. Some showers may
glance Orange county, but the morning hours should largely
remain dry.

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. 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 /SUNDAY 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 FRIDAY/...
Ridging follows into the middle of next week. The high pressure
settles overhead Tuesday before shifting south and east into
Wednesday. The latest modeling indicates a flatter shortwave
ridging around the periphery of the ridge, which may help lower
heights aloft. This may be able to bring a weaker frontal system
towards the area by next Thursday and/or Friday with most
models now depicting a return of rainfall.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
High pressure will move farther offshore today. A slow moving
frontal system will approach tonight.

VFR tonight, then MVFR cigs become increasingly likely late
tonight into the AM push for western terminals. Cigs likely
improve to VFR during late morning into early afternoon before
lowering again tonight.

Light S-SE winds into the AM push should increase to 10-15G20kt
by late AM. S-SE winds G20-25kt likely for most terminals
this afternoon.

There is increasing likelihood of MVFR/IFR conds with
shower/tstm potential tonight.

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

MVFR conditions likely for the AM push, and possibly returning
by the eve push. Showers/tstms possible after 00Z. Timing of
both may be off by an hour or so.

S-SE winds 15-20G25kt likely for KJFK/KLGA this afternoon, with
G30kt possible.

OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...

Late Tonight: MVFR/IFR conds likely with shower/tstm potential.

Sunday: MVFR/IFR cond possible with AM and PM
shower/tstm potential.

Monday through Wednesday: VFR.

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. Nearshore gusts to around 25 kt are likely this
afternoon and will be followed by ocean seas building to 5-6 ft
this evening into tonight. Have left the start of the SCA for
the ocean and South Shore Bays to 2 pm this afternoon. 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.

&&

.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.

&&

.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 from 6 AM EDT this morning through
     Sunday evening for NYZ075-080-081-178-179.
NJ...None.
MARINE...Small Craft Advisory from 2 PM this afternoon to 8 PM EDT
     Sunday for ANZ345-350-353-355.

&&

$$

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