Area Forecast Discussion
Issued by NWS Upton, NY

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134
FXUS61 KOKX 251932
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
332 PM EDT Wed Sep 25 2024

.SYNOPSIS...
High pressure across the Northeast continues to weaken and
slowly giving way to a frontal system that will move across the
area Thursday into Thursday night. High pressure will then
gradually build in from the north on Friday and remain across
the region Friday night through Monday as weakening low pressure
tracks to the south. Another frontal system approaches Tuesday
with a cold front passing through Wednesday.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
A warm front approaches from the west and may enter the western
zones by daybreak. Best thermal forcing/higher chances of showers
will be north and west of NYC. Models show elevated instability
moving in late at night, but thinking is that lift will be too weak
for a mention of thunder. Low temperatures mostly in the 60s.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...
The warm front lifts across the forecast area during Thursday with a
trailing cold front slowly passing through on Thursday night. The
highest chances of showers during the daytime remain north and west
where the stronger upward forcing will be. Chances then increase for
the rest of the region at night as the cold front shifts through.
Have left in a slight chance of thunder during the daytime and
evening with increased instability. Still some uncertainty regarding
how far south and east the likelihood of showers and potentially
brief heavy downpours reach as instability wanes along the slow-
moving cold front. With that said, no concerns for severe
thunderstorms or flooding for this event. Some post-frontal showers
are possible Friday morning across the southern zones, otherwise dry
but mostly cloudy conditions. Clouds may however thin out to partial
sunshine for the northern zones. NBM looked good for temperatures
through the short term.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
An upper ridge along the east coast will remain in place Friday
night into the beginning of next week as a closed low remain
offshore of the northeast coast, and another weakening closed low
continues to meander across the lower Mississippi Valley.
This low gradually weakens into an open trough Monday.
Meanwhile, at the surface high pressure builds into the northeast
Friday night into Saturday and remains into the beginning of next
week. With low pressure meandering to the south this is a chance of
precipitation mainly across the southwestern areas Friday night into
Saturday night. Then with the high pressure nosing into the region
dry weather is expected Sunday and Monday. However, there is
uncertainty with the strength of the high and where the low tracks,
and Friday night into Saturday may end up dry, and Sunday and Monday
may be wet. By Monday night the southern low is really weak or
dissipated, and any remnants will be picked up by another northern
stream frontal system moving to the north Tuesday into Wednesday,
with the systems cold front, at this time, expected to pass through
the region Wednesday.

Temperatures will be generally seasonable through the extended
period.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
High pressure gradually weakens as a frontal system approaches into
tonight.

Mainly MVFR thru the rest of the day. IFR cigs possible by evening,
but becoming likely for most terminals toward and after 6Z Thu. Slow
return to MVFR by late morning, but cigs may hang near or under 3
kft much of the day.

Scattered showers approach from the west late this afternoon, and
move through intermittently into early this evening. Western
terminals (KSWF, KHPN) expected to have higher likelihood of more
widespread SHRA activity, while KISP and KGON may remain mostly dry.
Additional showers, with potential thunderstorms, persist through
the day Thursday, though timing and coverage is low confidence at
this point. Highest chance for thunder is at KSWF, where PROB30 was
introduced after 18Z Thu.

SE flow 10 to 15 kt with gusts up to 20 kt thru remainder of the
day. Winds gradually shift southerly overnight into Thursday
morning. Similar speeds on Thursday.

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

Unscheduled amendments likely for changing flight categories due to
timing of cigs and presence of -SHRA through TAF period.

OUTLOOK FOR 21Z THURSDAY THROUGH MONDAY...

Thursday PM: MVFR or lower with showers/thunderstorms at times.

Friday: MVFR or lower in the AM with low stratus, becoming VFR by
afternoon.

Saturday-Monday: Mostly VFR.

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

&&

.MARINE...
Long period easterly swells from a slowly departing offshore low
will to continue to produce advisory-level waves on the ocean
through tonight. While 5 ft waves are still possible mainly in the
morning on Thursday, do not have enough confidence that they would
occur across enough of any one particular zone to extend the SCA
into Thursday. Waves otherwise prevail just below advisory
thresholds on the ocean through Friday with gusts below 25 kt on all
waters. Winds and seas across the forecast waters remain below
advisory levels Friday night through Monday night as high pressure
remains in control.

&&

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

&&

.TIDES/COASTAL FLOODING...
A high risk for the development of rip currents continues through
Thursday due to continued long period easterly swells.
Swells begin to slowly diminish Friday and Saturday. The rip current
risk is expected to also diminish to moderate for Friday.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents through Thursday evening for NYZ075-080-
     081-178-179.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EDT Thursday for ANZ350-353-
     355.

&&

$$

SYNOPSIS...JC/MET
NEAR TERM...JC
SHORT TERM...JC
LONG TERM...MET
AVIATION...DR
MARINE...JC/MET
HYDROLOGY...JC/MET
TIDES/COASTAL FLOODING...