Area Forecast Discussion
Issued by NWS Upton, NY

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307
FXUS61 KOKX 261444
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1044 AM EDT Wed Jun 26 2024

.SYNOPSIS...
A cold front arrives this evening into tonight with high
pressure building in afterwards. A warm front lifts north
Saturday followed by a cold front on Sunday. High pressure
returns for the a start of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Hourly temperatures were brought down a few degrees along the
southern side of Long Island. Otherwise, the forecast remains
on track. The latest 12Z CAMs still show isolated convection
starting around 21-23Z with a line of showers and thunderstorms
timed for later this evening into tonight.

An upper level trough moves out of the northern plains this
moving and amplifies through the Great Lakes region and moves
toward the east coast late in the day. The upper trough then
moves off the northeast and mid Atlantic coast late tonight.

Meanwhile a warm front across upstate New York into eastern
Pennsylvania will move across the region this morning. The area
then become warm sectored as the surface low moves well to the
north of the region. A southwesterly flow brings in warmer and
more humid air into the region. While the area will be warm and
humid heat indices are expected to peak into the lower and mid
90s, and heat advisories are not expected to be needed. A few
of the CAMs are showing the possibility o widely scattered
showers and thunderstorms later this morning as the airmass
destabilizes and a pre frontal trough develops. There is some
uncertainty as to how much CAPE there will be during peak
heating and at the time of the upper trough and surface cold
front. Instability may be more elevated by this evening, and
bulk shear increases to 40 to around 50 kt, mainly across the
interior. There is still a slight risk for severe thunderstorms
across the lower Hudson Valley and into southwestern Connecticut
and southward into northeastern New Jersey, New York City and
possible into western portions of Suffolk county. The primary
threat will be for damaging wind gusts late this afternoon into
this evening, and there is a possibility of large hail. Also, an
axis of heavier rain is possible across the lower Hudson Valley
into southwestern Connecticut.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
The surface cold front and upper trough will be exiting the
region early Thursday morning, probability by 12Z. The surface
low will be slowly tracking northward Thursday and the trailing
cold front may linger just to the east and south of Long Island
through much of Thursday. High pressure will be slow to build
east as the upper trough remains across the northeast into
Friday morning. There is a chance showers linger longer into
Thursday morning, however, once the front moves east dry weather
is then expected. However, clearing across the far eastern areas
may be slowed.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
High pushes off the New England Coast late in the day Friday into
Friday night, allowing a warm front to lift north of the area
Saturday. An unsettled pattern sets up Saturday night and Sunday as
a prefrontal trough and cold front move through. Some timing
differences with the models this far out, but for the most part,
they are generally 3 to 6 hours apart in the passage of the main
cold front late in the day Sunday into late Sunday night. High
pressure then builds in for Monday. Showers and thunderstorms will
be associated with the prefrontal trough and cold frontal passages
with MUCAPE values well over 1000 J/kg on Sunday.

The quick return flow Friday night and the approach and passage of a
warm front into Saturday will mean humidity levels on the rise, with
humid conditions Saturday and more so into Sunday. They then come
down again after the passage of the cold fronts Sunday, with
comfortable levels for most by Monday.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
A cold front approaches tonight which moves through late tonight
into Thursday morning.

VFR prevails most of this afternoon. Then, MVFR conditions
possible in association with any thunderstorms towards evening
PROB30 groups for TSRA towards 02-05Z for the western and city
terminals with arrival of pre- frontal trough. There may be some
isolated showers and thunderstorms prior to this time frame,
but coverage was not high enough to include in TAFs. Best chance
for these showers and thunderstorms is for city terminals and
points north and west for this afternoon. Any TSRA that develops
may contain strong gusty winds or hail, mainly for the
associated with the showers and thunderstorms this evening.

MVFR conditions possible tonight, though there is uncertainty in
exactly where. Highest confidence for eastern terminals, such as
KGON and less confidence for western terminals such as KEWR and
KTEB.

SW winds increase this afternoon 10-15 kt with gusts to 25 kt
possible. Sea breeze development at coastal terminals will move
well-inland this evening before shifting abruptly to the W
between 02-04z city terminals/points N&W as outflow from
approaching TSTMs overtakes the seabreeze. W-NW wind is
expected after midnight as the cold front moves through, but
this off +/- a couple of hours than forecast due to uncertainty
in the actual cold frontal passage.

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

Amendments expected with arrival time of t-storms this afternoon
into tonight.

Significant uncertainty with timing of wind shifts in
association with passages of prefrontal trough and cold front
and associated convection.

OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...

Thursday: Mainly VFR.

Friday: VFR.

Saturday: VFR with a chance of thunderstorms in the afternoon.

Sunday...MVFR possible in a chance of shra and tstms.

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

&&

.MARINE...
With a strong and gusty southwest flow ahead of a cold front,
winds and seas on the ocean waters remain at SCA levels today
and into tonight. With winds shifting to the northwest and
diminishing ocean seas fall below advisory levels late tonight,
and may remain elevated into early Thursday morning east of Fire
Island Inlet. With the southerly strong gusts a SCA remain in
effect until late tonight for the Long Island south shore bays.
Then sub advisory conditions remain through Friday. For the non
ocean waters winds and seas remain below advisory levels today
through Friday.

Winds and waves generally remain below SCA criteria from Friday
night through Saturday night. However, there is the potential
for SCA winds on Saturday as the pressure gradient increases
across the waters. Waves build on the ocean, but shouldn`t reach
5 ft until late Saturday night.

&&

.HYDROLOGY...
Around 0.5 to 1 inch of rainfall is forecast late today through
early Thursday morning. Locally higher amounts will be
possible, especially across the lower Hudson Valley into
southwestern Connecticut. Flooding of low lying, and poor
drainage areas is possible. Localized flash flooding cannot be
ruled out.

No hydrologic concerns Thursday night through the beginning of
next week.

&&

.TIDES/COASTAL FLOODING...
There is a high rip current risk at all local Atlantic facing
beaches today through early Thursday morning. The rip current
risk likely lowers to moderate later Thursday.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents until 9 PM EDT this evening for NYZ075-
     080-081-178-179.
NJ...None.
MARINE...Small Craft Advisory until 10 PM EDT this evening for ANZ345.
     Small Craft Advisory until 6 AM EDT Thursday for ANZ350-353-
     355.

&&

$$

SYNOPSIS...JP/MET
NEAR TERM...BR/MET
SHORT TERM...MET
LONG TERM...JP
AVIATION...IRD/JP
MARINE...JP/MET
HYDROLOGY...JP/MET
TIDES/COASTAL FLOODING...