000
FXUS61 KOKX 121144
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
744 AM EDT Thu Oct 12 2023

.SYNOPSIS...
High pressure will be in control through Friday. Low pressure
tracks east through the Ohio Valley on Saturday, with a
secondary low forming off the Mid Atlantic coast Saturday
night. This low potentially lingers offshore early next week as
high pressure slowly builds in from the west.

&&

.NEAR TERM /THROUGH TONIGHT/...
The forecast is mainly on track. Issued an SPS to address the
potential of patchy dense fog over portions of eastern Suffolk
County and SE CT as well as Southern portions of Nassau, Queens
and Brooklyn.

A zonal flow will be in place today as the region is in between a
500mb low centered over southern Quebec and a ridge axis shifting
through the MS Valley. Weak surface high pressure is the result, and
this will keep us dry through the day. Mostly sunny with seasonable
high temperatures of mostly 65-70.

A weak cold front passes through tonight. Moisture doesn`t look deep
enough to support showers, so expecting a continuation of dry
weather. Went with NBM for low temperatures for the most part,
however hedged by blending in the colder MAV and MET MOS for spots
that typically see stronger radiational cooling. Confidence in
decoupling winds behind a recent cold front passage is not high
enough to completely leave NBM out of the blend.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
The ridge axis aloft flattens as it approaches us Friday into Friday
night. After a mostly sunny day, moisture spilling over the ridge
axis will bring lowering and thickening clouds at night, but it
still looks like any rainfall holds off through the night. Cooler
high temperatures for Friday in the lower and mid 60s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
A shortwave embedded in a H5 trough swings east on Saturday before
emerging off the eastern seaboard early Sunday. As it does so,
surface low pressure moving through the Ohio Valley transfers energy
to a secondary low off the Mid Atlantic coast, with the center
passing just to the south of the region Saturday night into Sunday
morning. While guidance over the past day or so had been shifting
the track of these surface features farther south, it appears this
trend has ended for the time being with global ensembles in relative
agreement. Rain chances increase Sat AM, becoming likely for most in
the afternoon. A period of light to moderate rain is expected as the
primary low weakens and the secondary forms. NBM probabilities don`t
indicate a particularly high concern for heavy rainfall, with the
area remaining below 20% of seeing 0.50" in 6 hours through the
duration of the event. The low should skirt just south of the
region Sat night into Sun AM, with the main push of rain coming
to an end during this time. Sunday will be the drier day of the
weekend, though not entirely, with a few lingering showers
possible. Winds also increase on the backside of this system,
with occasional 20 to 25 mph gusts likely on Sunday.

Overall, it appears likely the rainfall gradient sets up over the
local region, with highest totals to the south and west, and lesser
amounts to the north. QPF through the weekend ranges from less than
a quarter inch for portions of interior southern CT, to over an inch
across NE NJ, NYC, and Long Island.

Elongated troughing lingers across the Eastern US and northwestern
Atlantic thereafter as a piece of the upper low is left behind and
potentially meanders nearby into mid next week. Forecast confidence
lowers here as guidance begins to diverge on how quickly this
feature is able to exit. At the least, cyclonic flow with occasional
rain chances and below normal temperatures look to persist for
several days. Largely followed the national blend of models for this
update.
-- End Changed Discussion --

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
VFR as weak high pressure remains in place.

Localized IFR conds early this morning at KJFK as fog bank moves
through, becoming VFR by 13Z. Light and vrb or weak northerly
flow through mid morning before westerly flow becomes
established at most terminals, continuing through the day, with
speeds remaining under 10 kt. Potential S/SW sea breeze
development in the afternoon for coastal terminals KJFK, KISP,
KBDR, and KGON. Winds veer NW late this evening and remain so
into Friday AM.

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

Timing of wind shifts and sea breeze development may be off by a
couple of hours.

OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...

Friday: VFR.

Saturday and Sunday: Rain with MVFR/IFR cond. NE winds 15-20G20-25
kt, becoming N on Sunday.

Monday: Chance of rain, MVFR cond possible.

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

&&

.MARINE...
Conditions remain below advisory levels through Friday with light
winds today and an offshore flow of 10-15kt on Friday. There could
be gusts close to 25kt late Thursday night into Friday morning
behind the passage of a cold front, but this would be isolated at
most.

Increasing NE flow behind an area of low pressure that passes to the
south should allow for gusts to exceed 25 kt on the ocean waters
beginning late Saturday night or early Sunday morning. This could
expand to remaining waters on Sunday with the tightened pressure
gradient. Ocean seas may top 5 ft during this time as well.

Wind and seas subside Sunday night, with sub SCA conditions expected
on all waters thereafter.

&&

.HYDROLOGY...
Dry weather through Friday night.

A period of rain is likely across much of the forecast area Saturday
into early Sunday. At this time, significant hydrological impacts
appear unlikely. However, there is the possibility of nuisance
flooding of urban and poor drainage areas Saturday into Saturday
night. Localized flash flooding cannot be entirely ruled out with
wet antecedent conditions and elevated soil moisture. Total rainfall
of up to an inch and a half of rain is possible, with the highest
amounts south and west.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$

SYNOPSIS...JC/DR
NEAR TERM...JC
SHORT TERM...JC
LONG TERM...DR
AVIATION...DR
MARINE...JC/DR
HYDROLOGY...JC/DR