Area Forecast Discussion
Issued by NWS Upton, NY

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928
FXUS61 KOKX 032100
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
500 PM EDT Wed Sep 3 2025

.SYNOPSIS...
High pressure along the Northeast and Mid Atlantic coasts will
drift slowly east and offshore through Thursday afternoon. A
cold front will approach Thursday night and wash out over the
area on Friday, then another cold front will approach and move
through from Saturday afternoon into Sunday. High pressure will
then build in from the Midwest early next week.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Dry conditions will continue under mostly clear skies and a
light S flow. As was the case last night, there could be some
patchy river and valley fog after midnight, maybe some patchy
low clouds in spots across SE CT and eastern Long Island. Low
temps will range form the lower 60s in/just outside NYC, to the
lower 50s in sheltered inland valley locations and in the Long
Island Pine Barrens.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
A subtle increase in temperatures is expected Thursday via WAA
S flow and a slight increase in heights aloft before a cold
frontal approach Thu night. High temps on Thu should reach the
lower 80s in most places away from south facing shorelines,
where mid/upper 70s are expected.

As shortwave energy rounds the base of an upper trough to the
west along with an approaching cold front to provide lift,
chances for showers and possibly a tstm will increase Thu night,
especially NW of NYC where likely PoP is fcst. These chances
will spread east into S CT and Long Island later in the evening
and overnight.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
By late this week, the region lies on the southeast periphery of
an anomalous 3-4 std closed low trough situated over Ontario
and the Upper Great Lakes, with ridging offshore. At the
surface, a series of cold fronts approach and attempt to move
through the region through Sunday.

Clouds to start Friday with the first of the frontal boundaries
attempting to work through before washing out. Cloud cover
erodes into late morning, and sets up a warm September afternoon
under mostly sunny skies. Soundings mix above 800 mb, and this
could allow for some gusts up to 25 mph Friday and Saturday
afternoons. 850 mb temps rise into the upper teens (C), and
should work down into the low to mid 80s for much of the local
Tri State. Humidity creeps up with the warmth, and heat indices
may approach lower 90s in the hottest locales of urban NE NJ,
with 80s elsewhere.

Best chance for wet weather looks to be Saturday afternoon into
the first half of Saturday night as more potent shortwave energy
rounds the base of the trough and pushes a cold front closer.
Deep southwesterly flow between the offshore ridging and
troughing to the NW will usher in a moister air mass ahead of
the front. Global models prog PW increasing toward 2 inches,
and with it, the chance for heavy downpours with any convection
that is able to develop, particularly north and west of NYC.
Still some uncertainty this far out on timing of the energy and
boundary, but potential for some thunderstorm activity along the
front/pre-frontal trough Sat aft/eve, though it still appears
most activity with the front could be post-frontal and off to
the NW of the region with best forcing displaced well NW of the
region. Lessening chances for thunderstorms moving east across
LI and SE CT, but could see some remnant showers work in during
the evening and nighttime hours.

The NW displacement of the trough makes for a slow progress of
the cold front through the region Saturday night, likely not
cleanly working through entirely until Sunday with trough axis
passage and secondary front, and this could lead to a few
additional showers. Humidity looks to lower significantly across
the forecast area by Sunday night.

Otherwise in the wake of the secondary passage, cooling down
early next week, with temperatures going from about 5 degrees
above normal, to around 5 below it as moderating Canadian
surface high pressure builds in from the west.

&&

.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
High pressure over the terminals will move offshore on
Thursday. This will allow a cold front to approach from the
west.

S to SE winds this afternoon around 5-10 kt, Will become light
and variable tonight. Winds on Thursday will once again be from
the S/SE with speeds 5-10kt in the morning and 10-15kt with some
gusts 20-25kt in the afternoon. The best chance for gusts will
be along the coast.

VFR conditions through the TAF period. There is a low chance of
stratus and patchy fog developing again early Thursday morning
with an onshore flow, but confidence remains low. The best
chances are across the eastern Long Island and southern
Connecticut.

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

No amendments expected.

.OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...

Thursday afternoon: VFR with S gusts 20-25kt. MVFR or lower
possible in showers and isolated thunderstorms at night.

Friday: MVFR or lower possible in any showers and isolated
thunderstorms mainly in the morning. S gusts 20-25kt.

Saturday: Mainly VFR. Low chance of MVFR in showers.

Sunday and Monday: VFR.

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

&&

.MARINE...
Sub-SCA cond expected into Thu night. There is still potential
for a brief period of 25-kt gusts in S flow late day Thu on the
ocean waters just E of Sandy Hook.

SW winds gusting toward 25 kt likely develop on the coastal
ocean waters Friday afternoon, and could linger into Saturday
as well with a cold frontal passage. Ocean seas will also build
toward 5 ft during this time, especially E of Fire Island Inlet.

Winds subside Sat afternoon into evening, shifting NW Sat night,
with seas falling below SCA. Conditions then appear to remain
under SCA criteria into early next week.

&&

.FIRE WEATHER...
On Thursday, S winds increase to 10 to 15 mph with gusts 20-25
mph, highest in the NYC metro area up into the lower Hudson
Valley. Min RH in the afternoon will be as low as 40-45% across
NE NJ up into the lower Hudson Valley, 45-50% across southern
CT, and 50-55% across Long Island. KBDI values are also running
over 300 for most of the CWA. With this in mind, in
collaboration with NYS DEC and WFO ALY decided to issue SPS for
elevated fire growth/spread potential for the lower Hudson
Valley for Thu 10 AM to 7 PM.

Wetting rainfall expected mainly NW of NYC Thu night, with
slight chance of tstms. Another round of wetting rains
expected from Sat afternoon into Sunday morning, especially from
the NYC metro area north/west.

&&

.HYDROLOGY...
Showers and thunderstorms associated with a cold frontal passage
on Saturday could produce localized downpours that result could
cause minor nuisance flooding in urban and poor drainage
locales. The overall flash flood risk is low.

&&

.TIDES/COASTAL FLOODING...
There is a moderate rip current risk for NYC and Nassau beaches
on Thursday with 2 to 3 ft ESE swells at 8 seconds, and an
onshore wind up to 15 kt, with higher gusts. A bit lighter flow
going east should mitigate the risk a bit, and low is forecast
for Suffolk beaches on Thursday.

The rip current risk is moderate across all local ocean beaches
on Friday, with increasing 3 to 4 ft S swells and sustained
winds near 15 kt. It`s possible that the risk may need an
upward adjustment in subsequent forecasts.

&&

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

&&

$$

SYNOPSIS...BG/DR
NEAR TERM...BG
SHORT TERM...BG
LONG TERM...DR
AVIATION...BC
MARINE...BG/DR
FIRE WEATHER...
HYDROLOGY...BG/DR
TIDES/COASTAL FLOODING...