981
FXUS61 KOKX 201120
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
720 AM EDT Sun Sep 20 2026

.WHAT HAS CHANGED...
No significant changes from previous forecast.

&&

.KEY MESSAGES...
1) Steady rainfall from frontal system moves in today and prevails
into this evening. Some moderate to potentially heavy rain at times
will be possible. No hydrologic impacts expected beyond some
possible localized minor flooding or ponding for low-lying and poor
drainage areas.

2) Gusty easterly winds and fetch towards mid to late week will
increase the potential for gales, high surf, high rip currents and
some coastal flooding. Otherwise, periodic showers and cooler than
normal temperatures expected.

&&

.DISCUSSION...
.KEY MESSAGE 1...
The zonal flow in the mid levels will make for a more progressive
pattern, allowing for faster movement of the wave of low pressure.
The mode of rain is more of a stratiform overrunning, with the
approaching warm front. The warm front comes near but is expected
to stay south of Long Island.

When the wave of low pressure moves across the region tonight,
there is some marginal elevated instability that develops in the
low levels, mostly along the south portions of the region. Models
show a near zero value for Showalter Indices, an indicator for
elevated instability.

The southerly flow becomes gusty today and the flow becomes more
northerly tonight. The rain will limit high temperatures to just
the low 60s to near 70 today and temperatures will not drop too
much tonight. Lows tonight are in the mid 50s to lower 60s.

The rainfall forecast has lowered for today through tonight
over the past few days. Much of the ensemble forecast members
indicate rainfall totals of near 1 inch or less. Our total
rainfall forecast is similar with much of the area within the
half inch to 1 inch range.

HREF indicates relatively heavier rainfall with its 10 percent
of 1 inch of rain within 3 hour period. Max rainfall rates
potentially reach 0.25 to 0.5 inch in one hour.

With these magnitudes of rainfall and rainfall rates, flash
flooding is not expected. As such, the Weather Prediction Center
still does not have the area shaded at all with its excessive
rainfall outlook for this time period through early Monday
morning.

Models still indicate some marginal elevated instability
towards the evening hours. This will make a possible embedded
thunderstorm. Just have mentioned this as slight chance. If
there is a thunderstorm, relatively higher chance of some brief
heavy rain.


.KEY MESSAGE 2...
There will be a persistent pressure gradient that will be setting
up towards the mid to late week period. This will have high pressure
remaining centered well to the north of the area with low pressure
remaining to the south of the area. This will drive an easterly flow
that will build fetch and seas.

Gusty NE winds at the surface will keep temperatures cooler than
normal. Forecast highs are only in the 60s most locations through
mid to late week.

The area has several chances of showers but the synoptic forcing
does not appear to be too much so no freshwater flooding is expected
with these showers throughout the week.

However, the easterly flow will mean more water itself from the
building fetch, adding to total water level forecasts. Ocean seas
forecast to reach in excess of 12 ft. There will be increasing
potential for high surf and associated ocean beach erosion mid to
late in the week.

Some surge guidance already indicating towards mid week with minor
coastal flooding with the increasing positive departures.
Astronomical levels will be increasing as we approach a full moon on
September 26th. Would anticipate multiple high tide cycles with
potential minor to possibly moderate coastal flooding mid to late
week.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A warm front becomes nearly stationary across the area today. A
cold front moves across the terminals tonight.

Conditions will lower to MVFR/IFR this morning with a steady
rain overspreading the area during the morning hours and
continuing through the early afternoon. Then, the steady rain
could become more showery or just a light mist or drizzle.
Conditions are expected to gradually improve tonight after a
cold front pushes across the region.

SE winds around 10kt will increase this morning to 10-15kt G15-
20kt, highest at the coastal terminals, then veer to a more
southerly direction in the afternoon. Tonight, winds will shift
to the NW behind the passage the cold front.

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

Amendments possible today for flight category changes. The
onset of MVFR could be off by a few hours. Forecast TEMPO IFR
might not occur, but there is also the possibility that IFR
prevails during the forecast TEMPO period.

.OUTLOOK FOR 12Z Monday THROUGH THURSDAY...

Monday: Becoming VFR. N-NE wind gusts near 20 kt.

Tuesday through Thursday: Chance of MVFR or lower in showers.
NE wind gusts 20-25 kt Tuesday and 20 to 30 kt Wednesday and
Thursday, highest at the coastal terminals.

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

&&

.MARINE...
A low approaches today and moves across the waters tonight. High
pressure then gradually builds in from the north with low
pressure remaining to the south of the waters.

A persistent pressure gradient will keep easterly flow in place
during the upcoming week. For Monday, ocean seas are expected to
build to near 5 ft. Gusty NE winds are expected as well with
gusts up to 25 kt on the ocean. A small craft advisory is in
effect for the entire day Monday across the forecast ocean zones.

SCA conditions likely continue Monday night into Tuesday,
becoming more widespread. Thereafter, gale potential through
much of the week for all waters. Even possible storm wind gust
potential for outer ocean towards the end of the week.

Ocean seas also build to near 12 to 14 ft for the mid to late
week period.

Rip Currents:
The rip current risk remains moderate today through Monday. Ocean
swells will be near 3 to 4 ft with more onshore components today
and increase up to near 5 ft Monday. Ocean swells further increase
to near 12 to 14 ft mid to late week.

Rip current risk could get to high for some ocean beaches on
Monday. SE gusty winds today will become more northerly tonight
into Monday. There is uncertainty Monday due to the flow becoming
less conducive to the building of surf height and that of rip
current risk. With this uncertainty, maintained a moderate rip
current risk through Monday.

Rip current risk gets likely to high towards mid to late week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 AM to 6 PM EDT Monday for ANZ350-
     353-355.

&&

$$

DISCUSSION...JM
AVIATION...BC
MARINE...JM