629
FXUS61 KOKX 181130
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
730 AM EDT Wed Sep 18 2024

.SYNOPSIS...
High pressure weakens and gives way to an approaching area of
low pressure today through tonight. The low hovers offshore
Thursday into Friday, moving a little farther away from the
region. Low pressure pushes further south on Saturday. High
pressure builds in from the northeast Sunday into early next
week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Rain developing south of Long Island evident on radar, will
eventually move in later today. Forecast mainly on track. POPs
chance morning into early afternoon for SW parts of area before
spreading farther north afternoon into early evening.

High pressure across the local region will weaken, and eventually
will give way to an approaching low from the south today into
tonight. Easterly flow remains, with an overall increase in low
level moisture with the airmass becoming more maritime.

Rain showers develop and spreads across the region today into
tonight. Models vary with the magnitude of the rain and where
the heaviest of rain occurs.

The mode of this looks to be overrunning stratiform, gradual lift,
favoring mostly light rain. Low levels with all the easterly flow
remain relatively cooler and more stable, precluding thunderstorm
possibilities. Some embedded heavier showers will be possible
though as indicated by some CAMs.

While the weather looks to be relatively quiet over the land, with
cool temperatures, breezy easterly flow and mostly light rain, more
active forecasts will be seen for marine and coast. SCA conditions
for ocean, high risk of rip currents and minor coastal flooding are
in the forecast. See marine and tides/coastal flooding sections for
more details.

Max temperatures today used the NBM 50th percentile, which is
cooler than previously forecast. Min temperatures for tonight
used a combination of NBM and consensus of raw and short term
guidance. This depicts slightly warmer temperatures across the
coast with slightly cooler temperatures across parts of the
interior compared to the previous forecast.

Manually increased POPs for tonight and especially for eastern
locations.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
For Thursday through Friday, the maritime airmass remains across the
region. With low pressure slowing down offshore, rain looks to
remain in the forecast for much of the region throughout this
timeframe. Cool temperatures, light rain and breezy easterly winds
remain. Still same active conditions for coast and marine with SCA
and potential for high rips and coastal flooding. See marine and
tides/coastal flooding sections for more details.

Manually increased POPs for Thursday and more so for eastern
parts of the region. POPs trended higher compared to previous
forecast.

Trended down with high temperature forecast for Thursday and
Friday compared to previous forecast.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
There were no significant changes made to the long term forecast.

*Key Points*

*Improving conditions should begin to occur Saturday, but especially
Sunday into early next week as high pressure builds  in from the
northeast.

*Temperatures start out near to slightly above normal Friday into
Saturday, but will trend slightly below normal Sunday  into early
next week.

Saturday may still see on-and-off showers due to the
proximity of the low to the area. Dry weather likely returns Sunday,
but some lingering clouds are possible. Coverage of clouds should
diminish further as ridging begins to build aloft on Sunday. Surface
high pressure over southeast Canada builds down across the northeast
into early next week. The high may then shift towards the Maritimes
on Tuesday as the ridge axis slides off the New England coast.

Highs will be in the 70s on Friday, warmest across the western half
of the area. Temperatures begin to trend down beginning Saturday but
especially Sunday into early next week as cooler air advects south
in associated with the building high pressure. High temperatures
Sunday into early next look to reach the upper 60s to low 70s,
slightly below normal for this time of year. It may also remain
breezy, especially near the coast due the pressure gradient from the
building high to the northeast and departing low pressure.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
Low pressure gradually approaches from the south today into tonight.

Mainly VFR this morning, with occasional MVFR possible through
13Z. VFR for the rest of the morning and afternoon, although
MVFR is possible at times in showers this evening into tonight.
Showers will start early this afternoon and may come in rounds
through tonight before clearing tomorrow morning.

Light E/NE flow this morning increasing to 10-15kt this afternoon
and remaining so into tonight and early tomorrow.

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

Possible MVFR/IFR through 14Z-15Z, But may remain FEW or SCT.

Onset timing of showers subject to amendments, as radar shows
the showers closer to our south than forecast. Its possible
showers may start mid/late morning.

OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...

Wednesday night through Friday: Periods of rain/showers possible
with with MVFR or lower conditions. NE-N gusts 20-25kt possible
mainly Thursday through Friday.

Saturday: Slight chance of showers with MVFR early in the morning,
then VFR. NE gusts around 25kt possible.

Sunday: VFR. NE gusts 20-25kt possible.

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

&&

.MARINE...
SCA conditions remain on the ocean through Thursday, likely
lingering thereafter through Friday. Non-ocean waters will be below
SCA initially today through tonight but then wind gusts are forecast
to reach SCA levels Thursday and some parts of the non-ocean waters
could still have SCA level gusts Thursday night and Friday as well.
Non-ocean waters with associated seas and waves are expected to
remain below SCA thresholds through Friday.

The rough SCA level seas and wind gusts likely remain into this
weekend, mainly for the ocean.

&&

.HYDROLOGY...
No hydrologic concerns with showers through Friday with
rainfall amounts of mainly less than an inch. Locally higher
amounts possible especially with any locally heavier showers.
PWATs potentially get into near 2 inches so perhaps those max
rain amounts could potentially reach 2 to 3 inches localized
which is indicated by some SREF members.

There are no hydrologic concerns through the long term period.

&&

.TIDES/COASTAL FLOODING...
Astronomical tides are running high this week due to recent full
moon. Increasing E flow will then help keep tide levels
elevated through the rest of the week and into the upcoming
weekend.

Departures above normal grow late this week into start of
weekend, with more surge. Potential for some moderate coastal
flooding, mainly across South Shore Bays which is noted in the
HWO.

Otherwise, minor coastal flooding today into tonight for western
shorelines. This AM have some statements for Fairfield and
Westchester coastlines as well as South Shore Bays and more
statements for tonight around times of high tides which also
include Lower NY Harbor. South Shore Bays have advisory
tonight. Minor coastal flooding localized this morning and more
widespread across South Shore Bays tonight with localized minor
coastal flooding for Lower NY Harbor and Fairfield and
Westchester coastlines.

A high rip current risk for ocean beaches continues through
Thursday due to building seas and gusty NE flow.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents through Thursday evening for NYZ075-080-
     081-178-179.
     Coastal Flood Advisory from 6 PM to 11 PM EDT this evening for
     NYZ178-179.
NJ...None.
MARINE...Small Craft Advisory from 6 AM to 6 PM EDT Thursday for ANZ331-
     332-335-338-340-345.
     Small Craft Advisory until 6 PM EDT Thursday for ANZ350-353-
     355.

&&

$$

SYNOPSIS...JM/BR
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...BR
AVIATION...BR
MARINE...JM/BR
HYDROLOGY...JM/BR
TIDES/COASTAL FLOODING...