-- Discussion containing changed information from previous version are highlighted. --
357
FXUS61 KOKX 251437
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1037 AM 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 through early next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
Rain chances have been adjusted a little based on the latest
radar obs and CAMs. The forecast is otherwise on track.

A longwave trough over the mid section of the country will
continue to split as the northern energy heads tracks across
the Great Lakes today, and the southern closed low becomes
cutoff over the Tennessee Valley. The associated frontal system
preceding these features will ever so slowly work east with
warm advection showers gradually working into the area from SW
to NE today. The better chances for rain will reside to the
north and west of NYC along with the better thermal forcing.
Otherwise, expect mostly cloudy skies with an easterly flow.
This should keep highs mainly in the 60s, which is several
degrees below normal.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
There have been some differences the last 24h, most notable is
the increase in rainfall amounts across the area. With the
ridge over the western Atlantic and the better lift with the
incoming upper trough to the north and west, there has been
uncertainty as to how far south and east the heavier rainfall
would get. The trend the last 24h has been for more rainfall
across the region. Warm advection showers will continue through
tonight into Thursday with the best chances remaining north and
west of the NYC. A warm front will pass through Thursday afternoon,
followed by the cold frontal passage at night. Airmass
gradually destabilizes on Thursday with dew points getting well
into the 60s with highs in the 70s. Not looking at a severe
weather threat, but any deeper convection will briefly enhance
rainfall rates. Rainfall amounts are forecast to range from a
couple of tenths along the coast, to in excess of a half inch
across interior NE NJ, the Lower Hudson Valley, and interior SW
CT. These amounts are likely to change some as the forecast area
resides on the SE side of the heavier rainfall axis. Subtle
shifts will make a difference. The other question is how much
convection with the actual cold front will make it down to the
coast. Latest CAMs do show a weakening trend as would be
expected due to the time of day.

As for temperatures, it will be above normal during this time
and quite humid with highs in the 70s and lows in the 60s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
The area remains sandwiched between a departing trough to the east
and a cutoff low pressure system over the Mississippi Valley Friday
night and into Saturday with a ridge building generally overhead
between these two systems. At the surface, a high pressure system
drops down out of Canada and moves over much of the Northeast US.
This should largely result in dry conditions for much of the area
over the weekend. Global model trends recently have allowed for a
subtle weakening of the ridge over the area which results in perhaps
some shower activity approaching the area from the southwest during
the weekend, but for now kept PoPs at a minimum for the southwestern
most areas as consensus at this time seems to be drier than not.

The cut off low over the Southeast US will approach the area as it
becomes reconnected to the large scale flow which may result in a
better chance of shower activity during the beginning of next week,
but most models weaken the low to the point where any showers will
be light and widely scattered as the low shifts off the US coast to
the south of the CWA. Another frontal system looks to approach from
the west providing for another chance of showers by the middle of
the week.

Temperatures will be generally seasonable through the extended
period.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
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High pressure gradually weakens as a frontal system approaches
into tonight.

Ceilings decline to MVFR through early afternoon at most
terminals, then MVFR thru the day. IFR cigs possible by early
evening, especially in any SHRA. Better potential for IFR cigs
tonight and into Thursday morning.

Scattered -SHRA approaches from the west, with rain chances
beginning to increase after 18Z, but mainly after 00Z for the
NYC and eastern terminals. Western terminals expected to have
higher likelihood of more widespread SHRA activity. KGON may
remain entirely dry and VFR.

E winds increase 10 to 15 kt with gusts peaking near 20 kt.
Winds then gradually shift to the SE tonight into Thursday
morning.

 ...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 tonight.

OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...

Thursday: Chance of MVFR/IFR in showers/thunderstorms. Cigs
improve to VFR late in the afternoon.

Friday-Sunday: VFR.

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

&&

.MARINE...
Long period easterly swells from a slowly departing offshore
low will to continue to produce advisory level seas on the ocean
through tonight with waves possibly remaining near 5 feet
through Thursday evening. Ocean seas likely fall below 5 feet
Thursday night into Friday as swells continue to diminish and a
northerly flow develops behind a cold front. Thereafter, sub-
SCA conditions are expected on all waters through the beginning
of next week.

&&

.HYDROLOGY...
There are no hydrologic concerns through early next week.

&&

.TIDES/COASTAL FLOODING...
The high risk of rip currents continues through Thursday due to
continued long period easterly swells. Some improvement is
expected on Friday as swells gradually diminish.

&&

.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...DW/MW
NEAR TERM...JC/DW
SHORT TERM...DW
LONG TERM...MW
AVIATION...DR/MW
MARINE...DW/MW
HYDROLOGY...DW/MW
TIDES/COASTAL FLOODING...