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243
FXUS61 KOKX 252346
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
746 PM EDT Tue Jun 25 2024

.SYNOPSIS...
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High pressure builds off the Eastern Seaboard into tonight. A
warm front moves through late tonight, and then moves northeast
and away from the region early Wednesday. A cold front then
approaches from the west, moving across late Wednesday night
into early Thursday. High pressure gradually builds in
thereafter through Thursday night, becoming centered over the
area Friday morning and moving offshore Friday evening. A warm
front lifts north of the area Friday night into Saturday,
followed by a cold frontal passage sometime on Sunday. High
pressure then likely builds in for early next week.
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&&

.NEAR TERM /THROUGH WEDNESDAY/...
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The forecast is on track this evening as winds expected to
become more SW and gusty closer to the coast over the next few
hours. Clouds are expected to increase from the west later this
evening ,but will be higher level mid and upper deck with some
transparency.

For tonight, nearly steady zonal mid level height tendency.
Vort max moves across during the evening, with most of its
energy north of the area. At the surface, high pressure moves
farther offshore. A warm front approaches from the west and
eventually moves into the region. This warm front is forecast to
move northeast of the region early Wednesday.

Some CAMs are depicting a few showers potentially developing
across parts of the region in and around NYC as well as
locations to the north and west. Will only have slight chance
POPs for this. Forecast lows tonight were a blend of MOS
consensus and NBM, ranging from the upper 60s to lower 70s for a
majority of the region. It will start to feel more humid as well
as the dewpoints are forecast to rise into the upper 50s to
lower 60s.
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&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/...
On Wednesday, more height falls are forecast at 500mb. A mid
level trough approaches from the west. Even stronger height
falls are forecast for Wednesday night as the trough eventually
moves into the area late Wednesday night. This trough will exit
the area early Thursday and shift east of the area Thursday
afternoon.

At the surface, the warm front will be moving northeast away
from the region early Wednesday. The area will be in the warm
sector during the day Wednesday. There are model indications of
a pre-frontal trough developing during the day but not much
convective development along it. This is probably due to mixing
down of drier air. Dewpoint depressions of near 25 degrees are
forecast, limiting the moisture available for convective
initiation. A cold front will be approaching from the west.

Chances for showers and thunderstorms begin north and west of
NYC in the first half of the afternoon and then in the second
half of the afternoon chances for showers and thunderstorms are
forecast farther east into NE NJ, NYC, Western Long Island, SW
Connecticut. Late afternoon, expecting showers and thunderstorms
to become likely north and west of NYC.

The cold front eventually moves into the region Wednesday night.
Highest vertical forcing with more positive vorticity with the
shortwave moves in Wednesday night. Showers become likely ahead
of it for Wednesday evening across the entire region. The chance
for thunderstorms will remain as well.

A note about thunderstorms. There could be strong to severe
thunderstorms within the region. SPC has highlighted much of the
western half of the region with a slight risk of severe
thunderstorms and a marginal risk for severe thunderstorms to
the east for the remainder of the region. Models show limited
CAPE (near or less than 1000 J/kg) but 40-50 kt of bulk shear
0-6 km AGL. The CAPE becomes elevated Wednesday night, so do
expect some maintenance of convection across the coastal
sections of the region. Also see hydro section for flooding
potential which will have a marginal risk especially for any
strong or severe thunderstorms. PWATS are forecast to reach near
2 inches, highest along the coast Wednesday night. The main
threats with any severe thunderstorms would be damaging winds and
large hail.

For Thursday, the cold front may still be lingering nearby in
the morning and will remain across eastern parts of the region.
The front moves fully offshore by early afternoon.

Chances for showers remain late Wednesday night into Thursday
morning. Dry conditions expected to return for the whole
forecast region Thursday afternoon.

Regarding temperatures, SW winds tonight into Wednesday with
warm air advection. Warmer night is expected tonight compared to
previous night with more humid conditions. Highs forecast
Wednesday will be relatively similar to those of the previous
day with some more humidity but will be a few degrees cooler
along the coast. Only have max heat indices getting to lower
90s within NYC and part of NE NJ into the mid 90s. Overall, the
entire forecast region is expected to stay below heat advisory
criteria.

Highs forecast more in the 80s for Thursday with drier
conditions as dewpoints drop into upper 50s to lower 60s.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
High pressure starts to build in Thursday night as heights rise
aloft in a zonal flow. The airmass that will build in will bring
drier and a bit cooler conditions to the area. Friday looks to be
the pick of the long term. High pressure moves overhead early in the
day and then offshore by the evening. This will lead to sunny and
dry conditions, with high temperatures potentially a few degrees
below normal for late June. Dewpoints in the low 50s will give a
comfortable feel to the air.

By Friday evening, the synoptic surface flow will become southerly
(outside of any areas that will already be in a southerly flow from
seabreezes) in response to the high moving offshore. A warm front
looks to move through sometime later Friday night into Saturday
morning. This will start to bring in warm and moist air ahead of the
next cold frontal passage.

Between a pre-frontal trough and a slower moving cold front, chances
for showers and thunderstorms last from Saturday afternoon through
Sunday night. At this time there are no hydrologic issues expected,
but it is worth nothing that pwats look to be between 2.25 and 2.5
inches. In this environment, any shower or thunderstorm will likely
be able to produce heavy downpours.

The front pushes through sometime on Sunday and then high pressure
looks to build in for the beginning of next week leading to dry
conditions.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
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A warm front lifts north of the area tonight as a cold front
approaches Wed night.

VFR prevails tonight through Wed. Possible MVFR conditions in
association with any thunderstorms towards Wed eve. PROB30 groups
for TSRA towards 21-22z for the western and city terminals with
arrival of pre-frontal trof. However, this activity may hold off
until 00z or just after. Best chance of Wed afternoon convection
will be for the city and NW terminals. Any TSRA that develops may
contain strong gusty winds or hail.

SW winds settle in close to 10 kt at the metro terminals tonight.
Winds diminish a little more for the outlying terminals tonight and
will be under 10 kt, before increasing again during the day Wed.


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

No unscheduled amendments are expected.
Arrival time of t-storms late Wed / Wed eve remains uncertain.

OUTLOOK FOR 00Z THURSDAY THROUGH SUNDAY...

Wednesday night: Pockets of MVFR possible with showers and
thunderstorms during the evening and may extend into a portion of
the overnight. S winds shift to the W, then NW.

Thursday: Mainly VFR, MVFR or lower possible early in the morning in
shower and thunderstorms.

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
-- End Changed Discussion --

&&

.MARINE...
Small craft advisory, SCA, remains in effect for the ocean
zones south of Long Island 6PM tonight through Wednesday night.
Decided to add in South Shore Bays with SCA. The South Shore
Bays have SCA from 8PM tonight until 10PM Wednesday night.

Already starting to have Ambrose jet form along western ocean
zone and more gusty SW flow is expected to continue through
tonight and into Wednesday as well as Wednesday evening including
the South Shore Bays. There may be some 25 kt gusts farther north
for other non-ocean zones as well for tonight through Wednesday
evening but those will probably just be occasional.

Late Wednesday night, SCA conditions will just remain on the
ocean with non-ocean waters expected to have below SCA
conditions.

SCA conditions could linger into Thursday on the ocean, mainly
due to seas, but otherwise would expect conditions to become
below SCA.

Winds and waves generally remain below SCA criteria from
Thursday night through early next week. However, there is the
potential for SCA winds Saturday afternoon through early Sunday
as the pressure gradient increases across the waters ahead of a
cold frontal passage. Wind gusts could reach 25 kt on all waters
and waves could reach 5 ft on the ocean waters. Conditions then
likely lower for the start of next week.

&&

.HYDROLOGY...
Around 0.5 to 1 inch of rain forecast Wednesday afternoon
through Thursday morning. Locally higher amounts will be possible.
Marginal risk of flooding, especially Wednesday night, and for
poor drainage and low lying areas within any potentially strong to
severe thunderstorms. Localized flash flooding cannot be ruled
out.

At this time, there are no hydrologic concerns Thursday night
through early next week.

&&

.TIDES/COASTAL FLOODING...
There is a high rip current risk at all local Atlantic facing
beaches today through Wednesday evening and likely lowering to
moderate for Thursday.

&&

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

&&

$$

SYNOPSIS...JM/JT
NEAR TERM...JM/JT
SHORT TERM...JM
LONG TERM...JT
AVIATION...JE
MARINE...JM/JT
HYDROLOGY...JM/JT
TIDES/COASTAL FLOODING...