000
FXUS61 KOKX 132013
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
413 PM EDT Wed Sep 13 2023

.SYNOPSIS...
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A cold front and wave of low pressure continue to move across
the region, eventually moving entirely east of the region late
tonight. High pressure then builds in on Thursday, remaining
centered to the north and west through Friday, before weakening
over the weekend. At the same time, Hurricane Lee is forecast
to pass offshore to our east. A weak frontal system impacts the
region early next week.

Monitor https:/www.weather.gov/okx/tropical or
https:/www.nhc.noaa.gov for the latest NHC forecasts on Hurricane
Lee.
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&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
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The cold front is within the region, extending from South
Central CT southwest through Western Long Island. East of here
is where there are higher POPs for showers and thunderstorms and
especially across Southern CT, where there was heavier rain, the
threat for flash flooding continues, though expect Fairfield CT
to have most convection end by early this evening. New Haven
through New London CT, convection occurs more into this evening.

Flood watch remains in effect for Fairfield CT until 6PM this
evening and for New Haven CT, Middlesex CT, and New London CT
until 2AM Thursday. Precipitable waters near 1.5 inches for the
eastern half of the area initially but decreasing more tonight
from west to east.

CAPE will be limited but more directional wind shear in the low
levels will increase helicity. The bulk shear increases 0-6km
AGL to near 40-45 kt. There will be the possibility for some
thunderstorms to have damaging winds as well as exhibit rotation
so a brief tornado will be possible as well. Overall, a marginal
severe thunderstorm threat.

Upper level height falls continue as the upper level trough axis
moves in. The surface cold front and low eventually move east of the
area. Showers and thunderstorms linger out across Long Island and
Southern CT going into tonight. Chances for showers and
thunderstorms lower to the west with mainly dry conditions
eventually getting established from west to east later tonight.
For Southeast CT and Long Island, these drier conditions get
established overnight.

Southern CT is where the flood watch remains and which is mostly
still east of the approaching cold front and where there has been
earlier heavy rain. Here, the excessive runoff will occur more
easily. This location will also be closer to the right rear quad of
the upper level jet so more enhanced vertical lift will be likely
here compared to locations farther south. Also, more instability
will be present across this areas as well.

Drying conditions with more northerly flow eventually settles into
the region from west to east later tonight. Some cold air advection
can be expected late tonight. Lower temperatures for the lows
compared to recent nights.
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&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
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Dry conditions expected Thursday through Thursday night with
near normal temperatures.

On Thursday, upper level heights will rise, with a weakening
upper level trough. The trough moves north with most energy as
conveyed by mid level positive vorticity advection. The back end
of the trough approaches. At the surface, the cold front will
move well out into Atlantic with high pressure starting to build
into the local area from the north and west. The high pressure
area will be centered across the Great Lakes.

On Thursday night, upper level heights are more steady, showing
a weakened trough axis along the back end that will be moving
in. At the surface, high pressure will continue to build in
partially but will remain centered across the interior parts of
the Northeast and across the Eastern Great Lakes.
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&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
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Not much change in the long term period and stuck fairly close to
the NBM/official forecast.

On Friday, high clouds start to move into the area in advance of
Lee. Temperatures will be in the upper 60s and lower 70s. Northerly
winds between inland high pressure and Lee will also be on the
increase to 15G25mph as the pressure gradient increases between
inland high pressure and the outer circulation of Lee.

The strongest winds associated with Lee are expected to arrive
Friday night and continue into Saturday, with winds backing NW on
Sat as the hurricane passes well east. The hurricane`s wind field
will be expanding in size as it moves northward, and winds
especially across coastal SE CT and eastern Long Island could become
strong, sustained 25-30 mph with gusts up to 40 mph possible. Can`t
rule out tropical storm force winds in those areas right near the
shoreline in areas with a good NW-N exposure.

NBM still bringing some POPs to portions of eastern Long Island and
CT on the periphery of Lee, with only light rainfall amounts
expected.

Lee lifts to the north with mainly dry conditions on Sunday. A cold
front and upper level shortwave will move across the region on
Monday, which may result in a slight chance or isolated shower or
two. Dry conditions return for the middle of the week.
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&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
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A cold front moves across the terminals this afternoon and evening.
High pressure then builds in tonight through Thursday.

Mainly VFR. There is still a chance for a few showers and
thunderstorms east of the NYC metro terminals through early this
evening as the cold front continues moving through the region. Any
lingering showers this evening should dissipate around 00z.

Winds ahead of the front will be S-SSW around 10 kt, but will shift
to the W and NW behind the cold front through this evening. Wind
speeds may weaken after 00z but a gradual increase early Thursday
morning as winds shift towards the NNW-N. This flow continues on
Thursday 10-13 kt.

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

An isolated shower possible through 00z.

Timing of wind shifts in TAF may be off by 1-2 hours.

OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...

Thursday Afternoon: VFR. Occasional N gust around 15 kt possible

Thursday Night-Friday Night. VFR. N-NNE wind gusts around 20-25
possible, strongest Friday night.

Saturday: VFR. NW wind gusts around 20-25 kt for NYC metro, western
Long Island and western CT. NW gusts 25-35 kt possible eastern Long
Island and southeast CT.

Sunday-Monday: VFR.

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

.MARINE...
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Small craft advisory remains in effect for our ocean zones
through Thursday night due to higher seas with SCA wind gusts
developing Thursday night. Non-ocean waters remain mainly below
SCA conditions but wind gusts could occasionally gust to SCA
levels late Thursday night.

Ocean seas will be 8-12 ft Fri morning and peak between 9-14 ft late
Friday evening. Seas will remain high Friday night, then start to
decrease on Saturday as strong offshore flow develops. Seas
eventually drop below 10ft late Saturday, and by Sunday morning,
drop below 5 ft.

Sustained N-NW winds or frequent gusts from Lee could peak at
tropical storm force (35 to 40 kt) Friday night into Saturday,
mainly on the eastern ocean. Elsewhere, SCA conditions likely from
Friday into Saturday, with a few gusts up to 35 kt possible Friday
night/Saturday morning.
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&&

.HYDROLOGY...
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Flood watch remains for Southern CT. Flash flooding possible at
times. Flood threat trends down late this evening into
overnight.

Otherwise, no hydrological issues are expected through early
next week.
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&&

.TIDES/COASTAL FLOODING...
For Southern Suffolk and Southern Nassau, the high surf advisory
remains in effect until 8PM Saturday. For Brooklyn and Southern
Queens, the high surf advisory remains in effect from 9PM this
evening to 8PM Saturday. The high rip current risk for all ocean
beaches has been extended through Saturday evening.

For Suffolk and Nassau ocean beaches, large breaking waves of 5
to 7 ft will steadily build to 10 to 15 ft in the surf zone by
Friday. For Brooklyn and Queens ocean beaches, large breaking
waves of 5 to 7 ft tonight will steadily build to 6 to 12 ft in
the surf zone by Friday.

Beach flooding and erosion increases Thursday through Saturday.
Scattered areas of dune erosion and localized overwashes are
possible Friday into Saturday.

Any changes to these coastal hazards will be based on the
current fcst track and intensity of Hurricane Lee. Stay tuned to
the latest from the National Hurricane Center regarding the
forecast for Lee.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Flood Watch until 6 PM EDT this evening for CTZ005-009.
     Flood Watch until 2 AM EDT Thursday for CTZ006>008-010>012.
NY...High Risk for Rip Currents through Saturday evening for NYZ075-080-
     081-178-179.
     High Surf Advisory from 9 PM this evening to 8 PM EDT Saturday
     for NYZ075-178.
     High Surf Advisory until 8 PM EDT Saturday for NYZ080-081-179.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EDT Friday for ANZ350-353-355.
-- End Changed Discussion --

&&

$$

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