000
FXUS61 KOKX 042355
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
755 PM EDT Wed Oct 4 2023
.SYNOPSIS...
High pressure remains in place into the day on Thursday,
departing towards the Atlantic Thursday night. This will give
way to an approaching frontal system on Friday. The associated
cold front passes through Saturday into Saturday night, but low
pressure lingers over the Northeast into early next week.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Forecast remains on track this evening with high pressure in
place. Previous discussion follows.
Tonight should start off clear under high pressure with stratus
developing over the ocean. This will move over land overnight
with areas of fog likely developing along coastal areas and
river valleys in the interior. Patchy areas of the fog could
become dense at times, with the best chance for this just before
and after sunrise. The 12Z HREF hints at a 70-80% chance for
dense fog, particularly for immediate coastal areas and areas to
the east. Fog should clear by mid-morning.
Temperatures overnight will cool to the low-50s in areas with
elevation and in low-lying typical radiational cooling areas
thanks to light winds. Clouds developing later at night will
prevent areas from reaching the 40s. Otherwise, mid/upper-50s
expected across the area with low-60s in the NYC metro.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Surface high pressure moves east of us over the Atlantic and
offshore through the day tomorrow with partly cloudy skies. We`ll
remain dry, but afternoon temperatures will be cooler, only a few
degrees above seasonal values in the low/mid-70s.
Second night of onshore flow may lead to more fog development
Thursday night. Some warm air advection ahead of a frontal
system could help to develop some showers late Thursday night-
early Friday morning.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Surface high pressure well to our north and east will continue the
already prolonged period of SE-E onshore flow to start the period.
This will allow an increasingly humid air mass to advect into the
area and could lead to patchy light rain or drizzle on Friday. At
the same time, a digging upper trough approaches from the west,
becoming negatively tilted as it reaches the East Coast. This
likely helps pull TC Phillipe out in the open Atlantic back
west, transporting some of the associated moisture locally in
the flow. As the trough advances east, an associated surface
low will track well to our north and west. This low will drag a
cold front through the area late Saturday into Saturday night,
bringing the highest chances for rain as it moves through.
NBM probabilities for 1 inch of rain over any 6 hr period on
Saturday continue to be low (10-15%). Still, there remains the
possibility of a few locally heavy downpours, as well as few
thunderstorms with BUFKIT soundings indicating several hundred
joules of CAPE ahead of the front. The cold front moves through
Saturday afternoon, with winds increasing and veering westerly
behind it. Rain chances largely taper off early Sunday and a
cooler fall air mass advects in behind the fropa. The upper low
cuts off from the flow, meandering over New England or southeast
Canada through early next week. The deepening low to the north
should result in a blustery end to the weekend. Gusts 20 to 30
mph appear likely much of Sunday. After 60s and 70s Fri/Sat,
daytime highs tumble into the 50s and low 60s on Sunday, and
continue to remain below normal Monday and Tuesday. Largely
followed the National Blend of Models for this update, with
winds nudged closer to the 90th percentile this weekend.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
High pressure over the area gradually weakens while slowly pushing
offshore through Thursday and Thursday night.
VFR at most terminals until later in the overnight. Sub VFR
conditions are likely to develop first across eastern most terminals
as fog and stratus develop 06Z to 09Z, with most visibilities
lowering to IFR approaching the morning push. Stratus is expected to
develop, however there is uncertainty whether or not ceilings lower
to IFR or lower at the NYC metro terminals, with IFR to LIFR more
likely at the outlying terminals. The metro terminals should lower
to MVFR in fog. Conditions improve back to VFR Thursday morning at
13Z to 15Z.
Winds will be light with a S to SE component, otherwise light and
variable overnight, and light SE to S during the day Thursday. A few
terminals get between 5 to 10 kt in the afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Uncertainty with the exact timing and flight category with respect
to fog and low stratus development overnight. There remains
uncertainty towards ceilings actually developing.
OUTLOOK FOR 0Z FRIDAY THROUGH MONDAY...
Thursday night: sub VFR developing early, with IFR likely and
possible pockets of LIFR.
Friday: MVFR or lower with a chance of rain showers.
Saturday: MVFR or lower in rain showers.
Sunday: VFR. W winds 15-20kt with gusts up to 25-30kt.
Monday: VFR.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
Sub-SCA conditions are expected tonight through Thursday night
under high pressure.
Ocean seas build late this week, reaching 5 ft by Saturday morning.
Winds increase behind a frontal passage late Saturday, with 25 to 30
kt gusts likely developing on all waters Saturday night into Sunday.
These winds persist through early Monday before subsiding.
Ocean seas remain elevated above SCA criteria into early next week
as long period swells from distant Tropical Storm Philippe move into
the waters.
Refer to the National Hurricane Center, https:/www.nhc.noaa.gov for
official forecasts on Philippe.-- End Changed Discussion --
&&
.HYDROLOGY...
Showers are likely across the region Friday through Saturday as a
frontal system moves through. The showers may fall locally heavy at
times. Around an inch of rainfall is expected at this time. The
Weather Prediction Center continues to place the region in a
marginal risk of excessive rainfall for this event, indicating the
potential for nuisance flooding, as well as isolated flash
flooding.
&&
.EQUIPMENT...
Data from the Peconic River at Riverhead NY tidal gauge appears
to have improved. Will monitor the gauge over the next few days
to make sure it is in line with other nearby gauges.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...BR/DR
NEAR TERM...BR/DR
SHORT TERM...BR
LONG TERM...DR
AVIATION...JE
MARINE...BR/DR
HYDROLOGY...BR/DR
EQUIPMENT...