000
FXUS61 KOKX 292358
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
758 PM EDT Fri Sep 29 2023

.SYNOPSIS...
Low pressure will be moving southeast of Long Island tonight
into Saturday while slightly strengthening. The low pressure
area will slowly move farther east out into the Atlantic
Saturday night into Sunday. Thereafter, high pressure will build
in from the Great Lakes through much of next week.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
-- Changed Discussion --
***Flash flood watch remains through tonight for continued
 potential for considerable flash flooding***

Main area of rain roughly bisecting the cwa as of 23Z. The
forward progress of this pcpn has slowed, which will enhance the
flood threat in that area. Elsewhere, additional development
will continue to impact ern areas, while in wrn areas, chances
for additional hvy rain are decreasing, with the moisture likely
being limited by the activity across LI and CT.

The upr low shows up on water vapor over ern PA, and continues
to track ewd. Ahead of this feature, the dynamics will remain
favorable for pcpn. In addition, rivers continue to rise across
the area, with the Lodi currently at major flood stage. The
Bronx River also remains at major. Due to all of these factors,
the flood watch will be kept up for a little longer, despite
lowering chances across wrn areas for new flooding.

NE gusty winds remain across the coastal sections of the region
through tonight. Lows were taken from a consensus of raw model
data, ranging from the mid to upper 50s. Temperatures will
likely be right near the dewpoint with the saturated low levels
in place.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
Low pressure moves farther away southeast of Long Island
Saturday into Saturday night with mid level cutoff low moving
southeast of Long Island also. Vertical RH lowers considerably
between 850 and 500 mb during the day Saturday. Rain showers
will linger across the region Saturday morning and then
gradually taper off from NW to SE in the afternoon across the
interior areas. Rain showers in the forecast do not taper off
for Eastern Long Island and Southeast CT until early Saturday
evening. Drier conditions move in Saturday night with any
remaining chances for rain showers decreasing for the Twin Forks
of Long Island. Mainly dry conditions are anticipated for
Saturday night.

Max temperatures forecast Saturday were taken from a consensus
of raw model data, ranging from the mid 60s across western
sections to lower 60s across eastern sections. Min temperatures
Saturday night were taken from a consensus of MOS, ranging from
the upper 40s to upper 50s.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
There have been no significant changes to the long term, as
global ensemble guidance is in decent agreement with the overall
pattern. A rather quiescent and generally dry period is
expected along with a warm up into next week.

Closed, positively tilted upper low ejects off the east coast
to start, as a an amplified ridge shifts eastward from the
Central Plains. The ridge builds to the east Sunday through
Wednesday, with the ridge axis overhead by Wednesday. The ridge
axis heads offshore Wednesday night.

At the surface, low pressure heads east/southeast of the 40/70
benchmark on Saturday, with lingering showers across the
southern portions of the CWA though midday. Easterly flow will
continue through the day on Saturday, and into early Sunday,
keeping coastal sections under cloud cover for a good portion of
Saturday, while the interior should see some sun by late
afternoon. The pressure gradient begins to relax Sunday as the
surface low pulls away and winds become more northeasterly by
Sunday afternoon.

A strong high pressure then begins to dominate as it settles over
the northeast through Wednesday resulting in mainly dry conditions
for the region. Temperatures will be on the increase into midweek,
with highs in the mid to upper 70s across the NYC metro, northeast
NJ and the interior. At the coasts, highs in the low to mid 70s are
expected. Either way, these are near or just above average for the
time of year.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
Low pressure off the eastern seaboard will be moving southeast
of Long Island tonight into Saturday, and slowly move farther
east Saturday night.

MVFR to IFR this evening becomes widespread IFR to locally LIFR
with light to moderate rain continuing. Conditions, particularly
ceilings improve by late Saturday morning to MVFR west to east
and to VFR late afternoon into the evening. If the low moves
slower than expected conditions will be slower to improve.

Winds generally NE backing to NNE and N through the forecast
period. Gusts have been more occasional, and occasional gusts
will be likely, especially near the coast through tonight. Gust
will become more frequent Saturday morning, and then end, with
the winds diminishing Saturday evening.


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

Ceilings vary early this evening, between MVFR and IFR before
becoming IFR. Winds may also vary 10 to 20 degrees on either
side of forecast as the low moves slowly east.


OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...

Saturday Night through Wednesday: VFR.

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

&&

.MARINE...
SCA conditions expected on all waters. SCA for the ocean goes
until 8PM Sunday. SCA for non-ocean waters goes until 8PM
Saturday. There may be some occasional 25 kt gusts for eastern
non-ocean waters Saturday evening. Otherwise, mainly below SCA
conditions expected for non-ocean waters Saturday night.

Winds gradually subside Saturday Night through Monday as high
pressure builds in from the west.

&&

.HYDROLOGY...
-- Changed Discussion --
Around an inch of additional rainfall is expected thru Sat.
Some higher amounts can be expected across cntrl CT and LI.

Next high tide cycle going into tonight could very well
exacerbate flooding issues along the coast.

River and stream flooding is ongoing, with some rivers at
major.

Saturday and beyond, outside of any residual flooding and rivers
that are elevated, no additional significant rainfall is
expected.
-- End Changed Discussion --

&&

.TIDES/COASTAL FLOODING...
An approaching full moon will have rising astronomical tides (as low
as 1/4-1/2 ft needed to reach minor thresholds), combined with a
persistent and slightly strengthening E-NE flow and E wind
wave/swell today into Sat Am will have water levels solidly at minor
flood levels (up to 1 1/2 ft inundation) for vulnerable NY/NJ
harbor, Jamaica Bay, western Great South Bay, and coastal
Westchester/Fairfield communities, with localized minor elsewhere
across Long Island and NYC for the high tide cycles through at least
Saturday morning.

A bit more uncertainty on how widespread the minor coastal flooding
will be with the Saturday night and Sunday morning high tide cycles
as astronomical tides peak, but winds turn more to the N-NE and
gradually subside. Highest confidence in additional cycles of
widespread minor flooding is for the southern bays of Nassau and
Queens due to restricted tidal drainage, with perhaps more localized
minor flooding elsewhere.

In addition, continued beach erosion/escarpment will continue
through at least Saturday due to elevated water levels, 4-7 ft
breaking surf, and a strong E-W longshore current. Dune erosion
potential looks to be localized, with overwashes not expected.

Although our surf zone forecast season in over, the risk for
dangerous rip currents will continue into at least early next week
based on the wave conditions.

NOTE: The Peconic River at Riverhead tidal gauge is out of service
(had been reading too high). The gauge is being looked into by our
partners at the USGS.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Flood Watch until 6 AM EDT Saturday for CTZ005-006-009-010.
     Coastal Flood Advisory until 2 PM EDT Saturday for CTZ009.
NY...Flood Watch until 6 AM EDT Saturday for NYZ067>075-078>081-
     176>179.
     Coastal Flood Advisory until 2 PM EDT Saturday for NYZ071.
     Coastal Flood Advisory until noon EDT Saturday for NYZ178-179.
NJ...Flood Watch until 6 AM EDT Saturday for NJZ002-004-006-103>108.
     Coastal Flood Advisory until noon EDT Saturday for NJZ006-106-
     108.
MARINE...Small Craft Advisory until 8 PM EDT Saturday for ANZ331-332-
     335-338-340-345.
     Small Craft Advisory until 8 PM EDT Sunday for ANZ350-353-355.
-- End Changed Discussion --

&&

$$

SYNOPSIS...JM/NV
NEAR TERM...JMC/JM
SHORT TERM...JM
LONG TERM...DBR
AVIATION...JMC
MARINE...JM/NV
HYDROLOGY...JM/JMC
TIDES/COASTAL FLOODING...