000
FXUS61 KOKX 152032
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
432 PM EDT Fri Sep 15 2023

.SYNOPSIS...
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High pressure remains centered to the north and west of the
area through Saturday night, before weakening on Sunday. At the
same time, Hurricane Lee passes well east. A wave of low
pressure along a cold front moves in Sunday night and slowly
moves across on Monday. The front and low depart east of the
region Monday night. High pressure will then build in and across
the region thereafter through Friday.

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 /THROUGH SATURDAY/...
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The official forecast from the National Hurricane Center
continues to take Lee about 275 miles east of Montauk, NY late
tonight into early Saturday morning. Lee will then track
northward towards northeastern New England and the Canadian
Maritimes into Saturday.

The main sensible weather as Lee passes well offshore will be
from expanding high level cloud cover tonight as the storm
interacts with a strong jet streak to our north. The cirrus will
likely be streaming across the sky through Saturday afternoon.
The clouds should begin to diminish from west to east late
Saturday afternoon.

Mainly dry conditions are expected as the atmosphere below 500
mb remains very dry. Gusty NW winds are expected, but the
strongest winds are expected to remain well to the east. Gusts
around 20-25 mph are possible across eastern Long Island tonight
and then will expand and increase to 25 to 30 mph on Saturday. A
few gusts to around 35 mph are possible across the forks of Long
Island and southeast Connecticut. Wind gusts from the NYC metro
on N and W will be weaker and generally around 20-25 mph on
Saturday. Winds diminish from west to east late Saturday
afternoon into the evening.

Lows tonight will fall into the 50s inland to around 60 degrees
near the coast. Highs on Saturday will be close to normal in the
lower to middle 70s.
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&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
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A weak upper level ridge will build over the northeast Saturday
night behind Lee. Surface high pressure will still be to our
north and west, but will gradually weaken. Any lingering high
clouds will clear leading to a cool night with lows in the upper
40s and low 50s inland and middle to upper 50s elsewhere.

The ridge shifts to the east ahead of the next shortwave trough that
approaches on Sunday. High pressure weakens further and shifts
offshore as a cold front associated with the trough begins to
approach from the west. Dry conditions will be maintained through
the day on Sunday, but should see increasing clouds from the west
late in the day. High temperatures trend slightly above normal in
the middle and upper 70s.
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&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
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Upper level trough and surface cold front will be the main
synoptic features Sunday night and Monday. This will bring rain
showers along with some possible thunderstorms especially along
the coast. Instability conveyed by numerical models is not very
high and only a few hundred J/kg of CAPE at most, so left as
slight chance for thunderstorm probabilities.

The rain showers could become heavy at times, especially late
Sunday night and Monday. The moisture transport from the
deepening SW flow including the jet will tap into moisture
sources from the Gulf of Mexico and Western Atlantic.
Precipitable waters are forecast to get to near 1.6 inches from
GFS and NAM models. Flow from low to upper levels is nearly
parallel with that deep trough approaching so there will likely
be training of showers. There could be some minor flooding for
areas that receive multiple areas of heavy rainfall.

Rain showers taper off from west to east Monday night. The mid
level trough axis moves across Monday night with highest
positive vorticity shifting east of the region by overnight. Mid
level heights will begin to rise overnight Monday night and
into early Tuesday.

Mid level heights rise Tuesday through Friday with ridging aloft.
At the surface, high pressure will build in from the north and
west. This will keep subsidence and allow for dry conditions.

Regarding temperatures, they will not deviate much from normal
values overall through the long term period.
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&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
High pressure remains centered to the north and west and weakens
through Saturday. At the same time, Hurricane Lee is forecast
to pass well east late this evening through early Saturday.

VFR. A gusty N-NW flow will continue through the TAF period.

Today, winds will be mainly N at 10-15 kts with gusts up to 25
kts. KISP, KBDR and KGON will likely be a few kts higher. Gusts
may be more occasional than frequent through tonight. Winds
become more NW tonight into Saturday and a few kts higher,
likely peaking for KGON at or just under 30 kts.

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

Gusts may be more occasional than frequent through tonight.

OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...

Saturday Afternoon: VFR. NW wind gusts 20-25 kt for NYC and
Lower Hudson Valley terminals and 25-30 kt for the eastern
terminals. Wind gusts diminish Saturday night.

Sunday: VFR.

Sunday Night-Monday: MVFR possible. A chance of showers.

Tuesday-Wednesday: VFR.

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

&&

.MARINE...
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Have cancelled the Gale Watch on the ocean east of Moriches
Inlet. Confidence continues to increase for solid gales to
occur further east. Cannot completely rule out a few gusts to
around 35 kt late tonight into Saturday and will cover that in
the SCA. Have also extended the SCA on the ocean through
Saturday night as seas will be slow to subside below 5 ft. This
may occur Sunday morning. Otherwise, there have been no other
changes with the SCA continue has previously posted. Winds will
weaken below 25 kt late Saturday into Saturday night and should
remain weak on Sunday with high pressure over the waters.

Conditions on the waters are forecast to remain below SCA criteria
Sunday night through Wednesday night with a relatively weak
pressure gradient in place.
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&&

.HYDROLOGY...
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Total rain forecast to range from around a half to 1 inch
Sunday night through Monday evening. There could be locally
higher amounts and the range could change with subsequent
forecasts. Heavy rain will be possible at times, with possible
minor flooding in low lying and poor drainage areas.

Otherwise, no hydrologic problems expected through next week.
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&&

.TIDES/COASTAL FLOODING...
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High surf advisory and high rip current risk continue through
Saturday evening.

For Suffolk and Nassau ocean beaches, large breaking waves will
peak at 10 to 16 ft in the surf zone tonight into Saturday
morning, and for Brooklyn and Queens ocean beaches, peaking at 6
to 10 ft. This will cause widespread dune erosion and scattered
overwashes, causing some minor to moderate flooding to roads
and properties on the landward side of the dune. Areas along
Dune Rd in the Hamptons have experienced overwashes with the
last couple of high tides, with an increase expected

Coastal flood advisories continue for most of the shoreline,
with potential for reasonable worst case water levels bringing
minor coastal flooding of 1 to 2 ft of inundation for vulnerable
shoreline/coastal locations along LI Sound, the eastern bays of
LI and southern bays of LI/NYC. The most vulnerable locations
will be for north facing areas of the twin forks, Jamaica Bay
and Great South Bay exposed to open waters from a northerly wind
fetch.

Due to uncertainty of timing of surge with respect to high
tides Tonight or Sat late morning/early afternoon or in between,
the contribution of wave setup from tidal piling over several
tidal cycles, and the hybrid extra- tropical/tropical nature of
this storm, the forecast has been geared to a reasonable worst
case P-Surge/P-ETSS blended forecast.

Residual surge could result in localized minor coastal flooding
in bay areas with the Sat Night high tide, but low confidence on
this.
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&&

.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Coastal Flood Advisory from 7 PM this evening to 5 AM EDT
     Sunday for CTZ009>012.
NY...Coastal Flood Advisory from 7 PM this evening to 5 AM EDT
     Sunday for NYZ071-078-079-177.
     High Risk for Rip Currents through Saturday evening for NYZ075-080-
     081-178-179.
     High Surf Advisory until 8 PM EDT Saturday for NYZ075-080-081-
     178-179.
     Coastal Flood Advisory until 3 AM EDT Sunday for NYZ080-081-
     178-179.
NJ...None.
MARINE...Small Craft Advisory from midnight tonight to 8 PM EDT
     Saturday for ANZ331-335-340-345.
     Small Craft Advisory until 8 PM EDT Saturday for ANZ332.
     Small Craft Advisory from 6 AM to 8 PM EDT Saturday for ANZ338.
     Small Craft Advisory until 6 AM EDT Sunday for ANZ350-353-355.
-- End Changed Discussion --

&&

$$

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