000
FXUS61 KOKX 180856
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
456 AM EDT Mon Sep 18 2023

.SYNOPSIS...
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A cold front moves into the lower Hudson Valley and coastal New
Jersey early this morning, then becomes stationary as low
pressure passes to the south and east late this afternoon into
this evening. High pressure builds Tuesday and remains over the
area through early Friday before shifting offshore late Friday.
Low pressure then approaches from the south on Saturday, impacting
the area late over the weekend.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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A cold front moving into eastern Pennsylvania early this morning
will become nearly stationary later this morning across the
lower Hudson Valley into coastal New Jersey as an upper trough
moves slowly toward the area, with the flow becoming nearly
parallel to the front. Meanwhile, upper energy rotating through
the eastern portion of the upper trough was deepening a low off
the southeastern and Carolina coast. This low will track slowly
north to north/northeast today, and then pass to the east this
evening.Precipitable water values remain from around 1 1/2 to 1
3/4 inches today, with slow storm motion and rain tracking
across the same areas, locally moderate rainfall will occur. The
heaviest rainfall is expected across portions of southeastern
Connecticut and into Long Island as isentropic lift will be
maximized across these areas in addition to the slow moving rain
and training across the region. Also, isolated thunderstorms
will be possible across Connecticut and Long Island later this
afternoon, producing locally heavy rain, as a low level low and
thermal ridge move across the region. While CAPE and instability
will be rather weak, the upper lift with the low level low may
be enough for a few isolated thunderstorms.

The upper low becomes slightly negative late in the day into
this evening, and lifts the surface low to the northeast of the
region this evening, with precipitation ending.
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&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
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Tranquil weather will be across the region Tuesday through
Wednesday as an upper trough across the northeast moves to
southeastern Canada as an upper ridge builds into the upper
midwest and Great Lakes region, with heights rising across the
area Tuesday through Wednesday. Meanwhile, surface high pressure
builds into the area by Tuesday night and remains Wednesday.
Temperatures will be near seasonal normals.
-- End Changed Discussion --

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
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No real significant changes to the long term and stuck close to the
NBM during this period.

A fairly tranquil period in store for much of the extended with a
dry period continuing Wednesday night through Friday. Global
ensembles are in good general agreement with the evolution of the
synoptic pattern over this period, and as such the NBM was used as
the basis for this forecast update.

Ridge axis slowly builds to the east during midweek before moving
offshore by Saturday. By week`s end, a slow moving upper low
originating over the southeast pushes slowly north and is somewhat
impeded by the ridging in place over the northeast. As this upper
low progresses north, the chances for unsettled weather/clouds and
precipitation increase into next weekend.

With respect to sensible weather, dry conditions are expected under
subsidence and surface high pressure Wednesday night through early
Saturday. Some high level clouds may begin to move into the area by
Friday in advance of the system that approaches from the south.
Otherwise, the incoming air mass is not anomalously warm or humid,
so daily highs near climatological norms, in the mid and upper 70s,
are forecast through the period. Near normal lows are also expected,
in the upper 50s to near 60.

An inverted trough associated with the main sfc low over the
southeast will approach the area Saturday. Moisture advection
increases on Saturday (sfc dewpoints back into the 60s) with
probability of precip. chances increasing by Saturday afternoon into
Sunday. NBM probabilities of >1" in any 6 hour period through Sunday
remain low at this time, less than 10% over the past few cycles,
suggesting little concern for excessive rainfall rates with the
system at the onset.
-- End Changed Discussion --

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
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A cold front will approach tonight and stall over the area
today, while low pressure passes to the south and east late
today into tonight.

VFR to MVFR for the metro terminals to start off, with
conditions slowly deteriorating through the night. KTEB will
likely see prevailing MVFR conditions during the night as it is
closer to steadier rainfall, whereas KEWR, KLGA and KJFK will
see TEMPO MVFR conditions through daybreak. IFR conditions are
not as likely now for the metro terminals, but still possible.
Therefore, have a TEMPO group for these IFR conditions, and
prevailing at KTEB, where IFR is more likely.

Farther east, expecting MVFR cond in rain to hold off until
daybreak to day, with TEMPO IFR late this morning and possibly
hanging on thru the day at KISP/KGON.

SE-S flow generally less than 10 kt tonight should become E-NE
during the AM at the NYC metros, then NW mid to late afternoon.


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

Unscheduled AMD likely this evening to handle patch of MVFR cigs.
IFR cond could last longer than fcst into late morning or early
afternoon on Mon.

OUTLOOK FOR 06Z TUESDAY THROUGH FRIDAY...

Monday night: VFR. Occasional NW wind gusts of 15 to 20 kt possible.

Tuesday through Friday: VFR.

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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Winds and seas remain below SCA levels today across the forecast
waters. An increasing and gusty west to northwest flow develops
late this evening and tonight behind departing low pressure, and
gusts on the ocean waters may be near 25 kt at times. However,
southeast to south swells will be increasing late today into
tonight from distant Tropical Storm Nigel, with ocean seas
reaching SCA levels. The seas will remain elevated through
Tuesday, and possibly into Tuesday evening as swells continue. A
Small Craft Advisory has been issued for the ocean waters
tonight and Tuesday. Swells linger into Wednesday, and ocean
seas may be near SCA levels east of Moriches Inlet.

Toward Wednesday morning and through Wednesday winds and seas
will be below SCA level across the forecast waters.

Winds remain below SCA levels across the forecast waters
Wednesday night. East to southeast swells from distant Tropical
Storm Nigel could bring elevated seas to the ocean waters
Thursday and Thursday night.

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

.HYDROLOGY...
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Rainfall today into this evening will range from around 1/2
inch across the western and northern areas to as much as 1 1/2
to 2 inches across southeastern Connecticut and the twin forks
of Long Island. d overnight into Monday evening, with the higher
amounts across the eastern portions of the region. Localized
nuisance flooding will be possible where higher amounts occur.

No hydrologic problems are expected later this evening through
next weekend.
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&&

.TIDES/COASTAL FLOODING...
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There is a moderate rip current risk today. Tuesday there is a
moderate risk at the NYC, southern Nassau, and southwestern
Suffolk ocean beaches, and a high risk at the southeastern
Suffolk ocean beaches. A high risk may be needed at the
southwestern Suffolk beach Tuesday. This is in a SE to S 2-3
foot swell today, building to 4-5 feet Tuesday with 6-9 second
periods. Surf heights will be building to near 7 feet Tuesday
and a high surf advisory may be needed.
-- End Changed Discussion --

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 PM this evening to 6 PM EDT
     Tuesday for ANZ350-353-355.
-- End Changed Discussion --

&&

$$

SYNOPSIS...JP/MET
NEAR TERM...MET
SHORT TERM...MET
LONG TERM...JP
AVIATION...JP
MARINE...JP/MET
HYDROLOGY...JP/MET
TIDES/COASTAL FLOODING...