Area Forecast Discussion
Issued by NWS Upton, NY

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943
FXUS61 KOKX 141957
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
357 PM EDT Wed Aug 14 2024

.SYNOPSIS...
High pressure will be in place through Thursday night, with a
weak disturbance moving through during the day Thursday. High
pressure remains off the northeast and Mid Atlantic coast Friday
and Friday night as a frontal system slowly approaches from the
west. The frontal system continues to approach through the weekend
with its associated cold front moving through on Monday. A weak
trough lingers on Tuesday. High pressure builds in on Wednesday.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Any showers and isolated thunderstorms will diminish quickly after
sunset as the loss of diurnal heating will help stabilize the
atmosphere. Clouds will also quickly diminish, becoming mostly
clear within a couple of hours after sunset.

Otherwise, upper level low remains nearly stationary over the
Canadian Maritimes tonight, with it`s trough axis off shore
while weakening upper level ridge moves east from the Great
Lakes region.

Low tonight will be near normal, with temperatures ranging from
the upper 50s across the normally colder outlying areas, to the
upper 60s into the NYC metro area. Temperatures may be colder
than forecast in the outlying areas with decent conditions for
radiational cooling.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
The upper level low will continue to spin over the Canadian
Maritimes Thursday into Thursday night. A surface trough moving
through may provide enough lift along with the instability
aloft (cold pool associated with the upper low) to bring
another round of showers and thunderstorms during the late
morning into the afternoon as diurnal heating helps to
destabilize the atmosphere. Target area seems to be southeastern
CT and the Twin Forks of Long Island, as they will be closer to
the low, but anywhere across the forecast area may see a shower
or thunderstorm. Showers and thunderstorms will once again
quickly diminish as the sun sets and the loss of heating
stabilizes the atmosphere.

Otherwise, temperatures will trend a bit above normal on
Thursday, with highs in the middle to upper 80s and lows in the
60s and 70. Outlying areas will once again be cooler with
clouds diminishing right after sunset and winds continuing to be
light and variable overnight with lack of a pressure gradient.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
The long term period forecast remains fairly consistent from the
previous forecast as a trough remains over the western north
Atlantic Friday and slowly moves east Friday night into Saturday.
This will allow a slow moving frontal system to slowly approach
Friday night through Sunday and move into the region Monday. The
slow motion of the low is due to an amplifying upper ridge to the
east and the interaction and passage of Hurricane Ernesto well to
the east. Please refer to the NHC for official forecasts on Ernesto.
The upper trough will remain over the region Monday and Tuesday, and
weaken Tuesday night into Wednesday.

Temperatures have trended upward a couple of degrees for Friday,
especially across the interior, however, dew points remain in the
lower 60s, so heat indices will be near the air temperatures.
Humidity increases Friday night and through the weekend with
temperatures near or slightly below normal as rain and clouds will
be across the region.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
VFR with a surface trough moving through today.

Mainly N flow close to 10 kt expected. There may be occasional gusts
over 15 kt this afternoon/early evening. Outflow from some SHRA over
eastern Connecticut may eventually make it into the NYC terminals
and create a brief NE flow.

Sea breezes possible late this afternoon for coastal terminals, but
outflow from SHRA from the north may prevent sea breeze influence
altogether. A light N flow should resume for tonight and into
Thursday morning. Sea breezes once again possible Thursday afternoon.

A few SHRA and TS approaching from the north will be in the vicinity
of KBDR, KHPN into the afternoon. Additional isolated
afternoon/evening showers and possibly a tstm are expected. These
could bring brief MVFR vsby, locally gusty winds, and wind shifts.
Outflow from any of these could make it to some of the NYC metros
later in the evening and keep a stronger N flow going into the
evening, but this is too uncertain to include in TAF. Additional
isolated to scattered SHRA or TSRA possible Thursday afternoon but
confidence too low to include in the TAFs at this time.

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

Sea breeze may not make it into KJFK this evening.

OUTLOOK FOR 20Z THURSDAY THROUGH MONDAY...

Thursday: Slight chance of an afternoon/early evening shower and
possibly a tstm with brief MVFR cond and gusty winds, otherwise VFR.

Friday: VFR.

Saturday and Sunday: Showers likely with chance of tstms, especially
in the afternoon/early evening, and especially from the NYC metros
north and west. MVFR or lower cond possible.

Monday: Mainly VFR. MVFR or lower possible in any SHRA/TSRA in the
afternoon.

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

&&

.MARINE...
High pressure provides a weak pressure gradient and a light
wind regime overall through Friday with sub-SCA levels.

Winds and seas remain below SCA levels Friday. However, the
combination of southerly winds with an approaching frontal system
and increasing long period S to SE swells from Hurricane Ernesto
during Friday into Saturday will build ocean seas to 5 to 6 feet
Saturday, and 6 to 7 feet Sunday. Seas peak Sunday and subside Monday
into Monday night. A small craft advisory will likely be needed on
the ocean waters for Friday night through Monday night. Please refer
to the NHC for official forecasts of Hurricane Ernesto.

&&

.HYDROLOGY...
There are no hydrologic concerns through Friday. There is a chance
of moderate to heavy rainfall Saturday night into Sunday with a slow
moving frontal system. Possible impacts will be poor drainage and
urban flooding.

&&

.TIDES/COASTAL FLOODING...
There is a low rip current risk at the ocean beaches through early
this evening. The rip current risk will be increasing during
Thursday to moderate, and continue to increase into Friday, reaching
a high risk Friday afternoon. The increasing rip current risk is due
to increasing incoming SE to S long period swells from Hurricane
Ernesto. Please refer to NHC for official forecasts regarding
Hurricane Ernesto.

Minor coastal flooding may become possible early next week from
Sunday through Tuesday as swells build and as astronomical tides
increase due to the full moon on Monday the 19th.


&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$

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