Area Forecast Discussion
Issued by NWS Upton, NY

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509
FXUS61 KOKX 191129
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
729 AM EDT Thu Sep 19 2024

.SYNOPSIS...
Low pressure hovers southeast of Long Island through early this
evening and then moves slowly farther out into the Atlantic
thereafter through Friday night. Low pressure lingers offshore
through Saturday. High pressure builds in from the northeast
Sunday through Tuesday. A frontal system approaches from the
west Wednesday into Thursday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Upper levels depict an overall a trough pattern but are devoid of
any jet streaks or wind maxima over the local region.

A mid level trough remains across the area. PVA increases across
eastern sections of the region for the afternoon into early evening.

Low level jet starts to develop to the west and northwest of the low
center, potentially expanding and getting over eastern portions of
the region late today into early this evening.

Low pressure remains nearly stationary southeast of Long Island
right near the 40N/70W benchmark through today. Low pressure does
deepen during this timeframe, dropping nearly 4mb. NAM appears to
have more rain across the local area compared to the GFS, ECMWF and
Canadian models.

Conditions have been drier than previously forecast so going to
continue with a downward trend in POPs. BUFKIT model soundings are
also indicating lots of dry air between 900 and 600 mb, limiting
moisture needed for collision coalescence. Favoring the overall
drier consensus with regards to the rainfall forecast.
Expecting mainly dry conditions through today.

Slight chance to chance POPs spread from east to west across
Eastern Long Island and SE Connecticut this afternoon.

Max temps today use 3/4 MET (cooler) and 1/4 MAV (warmer).

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
Upper levels continue to indicate both a trough pattern and the
lack of any jet streak or wind speed maxima.

Mid level trough moves slowly east of the region, and eventually
becomes a cutoff low that slightly deepens Friday through Friday
night. Higher PVA remains mainly across eastern sections of the
region, Southern CT and Long Island.

Low level jet remains west to northwest of the low center and stays
just outside of the region or just brushing over the eastern parts
of the region within SE CT and Eastern Long Island.

Low pressure slowly moves farther out into the Atlantic and remains
within a few mb of its previous central pressure tonight through
Friday night.

Canadian and ECMWF models show more rain moving in from NE to SW
late tonight into early Friday to better agree with the NAM. GFS
still keeping the area dry. GFS still mainly dry Friday into early
Saturday and NAM for this particular time frame also decreased the
rain. The ECMWF and Canadian models depict relatively more rain
across the area, especially for Southern CT and Long Island,
compared to the NAM and GFS.

POPs adjusted to have chances for eastern sections, likely for
Friday with otherwise slight chances to the west for this
tonight through Friday night timeframe.

Drier conditions and less clouds and thereby warmer temperatures
for more western locations Friday compared to more eastern
locations.

Min temps tonight use MAV/MET even blend.

Max temps Friday use NBM.

Min temps Friday night use NBM with a slight adjustment up for Pine
Barrens LI.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
**Key Points**

*Improving conditions Saturday into Sunday as high pressure builds
into the region.

*Downward temperature trend to slightly below normal temperatures
expected by early next week.

*A frontal system Wednesday into Thursday will bring with it
additional chances for showers.

Global guidance continues to depict the slow moving upper low/trough
situated over New England to start the period. There are varying
degrees of eastward progression on Saturday, though there is
consensus that heights will begin to rise as the low moves east by
Saturday afternoon. Thus, expecting a cloudy, and windy, Saturday
with perhaps some lingering showers thRough Saturday evening,
primarily for eastern Long Island and SE CT. Northeast winds will
begin to relax by Sunday afternoon as the low departs and the
pressure gradient weakens.

Thereafter, upper ridging begins to build in with surface high
pressure nosing in from the north. Dry conditions are generally
expected Sunday through Tuesday. A slightly cooler airmass advects
into the area for Monday and Tuesday under easterly flow and highs
in the upper 60s and low 70s.

The airmass begins to moderate somewhat on Wednesday, though still
below normal in the low 70s, with increasing cloud cover and a
chance of showers from an approaching frontal system to the west.
Guidance varies on timing, with some starting showers as early as
Tuesday night, while others keep the rain away until Thursday
morning. Overall, not expecting this to be a very impactful system,
rather just another chance for passing showers as the low passes
north with a front dragging through our area.

The NBM was primarily used for the forecast, except some adjustments
were made to POPs using CONSALL and some low temperatures
were blended with BCCONSALL on Saturday, Sunday and Monday nights.

&&

.AVIATION /11Z THURSDAY THROUGH MONDAY/...
Low pressure remains offshore, southeast of Long Island,
through Friday.

VFR.

Winds remain NE to N increasing overnight, especially at the
coast terminals, then winds increase during the day today with
gusts 20-25kt. Gusts may drop tonight, but pick up again
tomorrow 20-25 kt.

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

No amendments expected. Should any be needed, it would likely
relate to wind gusts and/or directions being off.

OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...

Saturday: VFR. MVFR east of the NYC terminals possible in
showers, but low chance of occurring. NE gusts around 25kt
possible.

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

Monday...VFR.

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

&&

.MARINE...
SCA level seas remain on the ocean and are expected to stay through
Friday. SCA level winds will be more difficult to get but are
expected to get more into that range for Friday. SCA kept for non-
ocean waters as some model guidance continues to indicate SCA level
gusts for this afternoon and tonight. However, due to decreasing
confidence did not extend non-ocean zones through day on Friday with
SCA. Friday night, likely ocean remains with SCA with non-ocean
waters having some locations get SCA level gusts probably.

5-7 ft waves and 25-30kt gusts will continue to be an issue on ocean
waters this weekend and at the start of next week. While the LI
Sound and Bays may not see 5+ ft waves, gusts near 25 kt will be
possible until Sunday night.

&&

.HYDROLOGY...
There are no hydrologic issues through the middle of next week.

&&

.TIDES/COASTAL FLOODING...
Multiple rounds of coastal flooding are expected through this
weekend with low pressure churning offshore, giving a steady NE flow
and piling of water. That along with building seas, and a recent
full moon are leading to higher total water levels forecasts.

Today and tonight will feature minor coastal flooding for much of
the coastline across SW CT, NYC, and Western Long Island. Statements
and advisories are out to address this. It appears the morning into
afternoon today will be relatively higher of the total water levels
forecast looking through tonight. This continues but with more surge
on Friday. Widespread minor for most coastal flooding Friday.
Some coastlines Friday as a result will have their total water
level forecasts reach into the moderate coastal flood category,
particularly within the South Shore Bays and along the Western
Long Island Sound coastlines. This is where a coastal flood
watch has been issued. ETSS and just the 50th percentile of
Stevens are indicating this moderate coastal flood forecast. In
addition, Eastern Long Island and SE Connecticut could get
minor coastal flooding Friday.

More coastal flooding can be anticipated for this weekend during the
times of high tide. There will be minor to locally moderate coastal
flooding.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory until 2 PM EDT this afternoon for
     CTZ009.
     Coastal Flood Advisory from midnight tonight to 3 AM EDT
     Friday for CTZ009.
     Coastal Flood Watch from Friday morning through Friday
     afternoon for CTZ009.
NY...Coastal Flood Advisory until 2 PM EDT this afternoon for
     NYZ071-073-078-176-177.
     Coastal Flood Advisory from midnight tonight to 3 AM EDT
     Friday for NYZ071.
     Coastal Flood Watch from Friday morning through Friday
     afternoon for NYZ071-073-176-177.
     Coastal Flood Advisory until 11 AM EDT this morning for NYZ072-
     074-075.
     Coastal Flood Advisory from 8 PM to 11 PM EDT this evening for
     NYZ074-075.
     High Risk for Rip Currents through Friday evening for NYZ075-080-
     081-178-179.
     Coastal Flood Advisory until 2 PM EDT this afternoon for
     NYZ080.
     Coastal Flood Advisory from 8 PM this evening to 2 AM EDT
     Friday for NYZ080-178-179.
     Coastal Flood Advisory until noon EDT today for NYZ178-179.
     Coastal Flood Watch from Friday morning through Friday
     afternoon for NYZ178-179.
NJ...Coastal Flood Advisory until 11 AM EDT this morning for NJZ006-
     106-108.
     Coastal Flood Advisory from 8 PM to 11 PM EDT this evening for
     NJZ006-106-108.
MARINE...Small Craft Advisory until 6 AM EDT Friday for ANZ331-332-335-
     338-340-345.
     Small Craft Advisory until 6 PM EDT Friday 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...JM