000
FXUS61 KOKX 121340
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
940 AM EDT Thu Oct 12 2023
.SYNOPSIS...
-- Changed Discussion --
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.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Visibility and ceilings have improved, with mainly clear skies
across the region. Updated for the current conditions.
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.-- End Changed Discussion --
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
-- Changed Discussion --
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.-- End Changed Discussion --
&&
.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/...
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
&&
.MARINE...
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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.-- End Changed Discussion --
&&
.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/MET
SHORT TERM...JC
LONG TERM...DR
AVIATION...DR
MARINE...JC/DR/MET
HYDROLOGY...JC/DR