Area Forecast Discussion
Issued by NWS Upton, NY

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262
FXUS61 KOKX 300304
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1104 PM EDT Sat Jun 29 2024

.SYNOPSIS...
A warm front moves northeast of the region going into this
evening. A cold front approaches tonight into early Sunday and
moves across the area Sunday afternoon into Sunday night. High
pressure builds into the area from the northwest Monday through
Tuesday and pushes offshore late Tuesday into Tuesday night. A
warm front lifts north of the area on Wednesday. A cold front
approaches Wednesday night and stalls near the area through the
end of next week into the first half of next weekend.

&&

.NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
Line of showers associated with some middle level energy and a
warm front continues to weaken as it heads over Long Island. The
warm front will lift north of the area into early Sunday
morning. There is very little instability, but it does look like
elevated CAPE increases overnight. Some regeneration of showers
and possibly a thunderstorm looks probable especially near the
coast. Elsewhere, scattered showers with maybe a rumble of
thunder are possible. Brief downpours are possible, but the
forward speed will prevent any flooding issues despite the
increasing subtropical moisture over the area.

Think the strong low level flow will prevent any fog
development, but a few areas could see patchy fog along the
coast overnight. It will be muggy with lows struggling to fall
out of the 70s.

&&

.SHORT TERM /8 AM SUNDAY MORNING THROUGH MONDAY/...
Large scale numerical weather prediction models show a consensus
with mid level height falls continuing Sunday afternoon through
Sunday night. This will be ahead of an approaching strong
shortwave from eastern part of the Great Lakes through SE Canada.
The height falls appear to occur more rapidly compared to the
previous night.

The models indicate a return of positive vorticity advection
Sunday afternoon into early Sunday evening.

At the surface, a cold front will be approaching from the west,
eventually moving Sunday afternoon and then moving west to east
across the region Sunday afternoon into Sunday evening. The cold
front passes southeast of Long Island late Sunday night.

The models show 0-6 km bulk shear increases to near 40-50 kt
and potentially above 50 kt as well. This combined with surface
instability as conveyed by CAPE values between 2000 and 4000
J/kg across the region near NYC and locations north and west.
Less CAPE to the east with more marine influence. There will be
potential for strong to severe thunderstorms with damaging winds
and large hail possible. Primary threat would be damaging
winds.

The forcing further is evident from the local region being
relatively closer to the right rear quad of an upper level jet
streak from SE to NE from New England into the Canadian
Maritimes. This will provide for greater divergence aloft.

CAMs show ongoing convection south of Long Island for early
Sunday morning in the 6am to 10am timeframe. Then, shower
activity sparse with mainly dry conditions thereafter until
around 1-2 pm. From 1-2 pm, convection starts to redevelop north
and west of the forecast and may start to move into parts of
the Lower Hudson Valley. Between 2 and 5pm, the convection
develops and solidifies into a squall line as it moves southeast
farther into the local region, reaching through Southern CT,
northeast NJ, Lower Hudson Valley, NYC into much of Long Island.
Convection expected to linger across much of the area Sunday
evening with much of the activity gradually shifting to more
eastern locations. Eastern Long Island and Southeast CT could have
some lingering showers and thunderstorms for the first half of the
overnight.

PWATs will remain a little above 2 inches Sunday into early
Sunday evening for much of the region, again near 2.2 inches.
Flooding will remain possible with thunderstorms.

Also to note, some indication with max updraft helicity across
parts of the region, mainly across interior. This signals a
potential for rotation within thunderstorms. A brief tornado
cannot be ruled out.

Regarding temperatures, this will be quite dependent on cloud
coverage. Still even with abundant cloud coverage, warm air
advection expected to have much warmer high temperatures
compared to the previous day. Forecast highs are well into the
80s for most locations with values more in the lower 80s along
much of the coastline. Some parts of NYC and northeast NJ are
forecast to reach the lower 90s. Max heat indices can be
expected to be a few degrees above the actual temperature,
keeping the forecast region below heat advisory criteria. The
highest heat indices are forecast to be mainly between 90 and 95
with some 95 to 97 degree heat indices for mainly parts of
northeast NJ.

Overnight Sunday night into early Monday, dry conditions
expected to eventually re-establish across the region from NW to
SE. Forecast lows range from the upper 50s to mid 60s.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
The cold front will continue to push offshore Monday morning as the
upper level trough over western and central portions of the
Northeast treks southeast. This will be the focus for some lingering
showers for eastern areas Monday morning and early afternoon. The
high continues to build in for Tuesday and pushes offshore late in
the day Tuesday into Tuesday night. Meanwhile, upper level ridging
over the Great Lakes noses into the Northeast. This allows a warm
front to lift north of the region sometime on Wednesday, and the
associated cold front to start moving through sometime on Thursday,
which then may stall somewhere near the area through the end of the
week.

With high pressure in place, conditions should be dry through
Wednesday as the warm front lifts north too far west to bring any
precipitation. Precipitation is expected with the approaching cold
front and chances for showers and thunderstorms look to continue
through the first half of next weekend.

As for temperatures, they are expected to be seasonable through
Wednesday. With upper level riding nosing in on Thursday, warmer
conditions are forecast, with highs in the upper 80s to lower 90s
away from the coast. Similar readings are expected through Saturday.
Humidity levels will also be on the rise. Prior to Wednesday night,
dew points will generally be in the 50s to around 60. From Wednesday
night onward, dew points rise into the 60s to around 70.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
A warm front will continue to push NE through the terminals
overnight. A pre-frontal trough approaches and settles nearby on
Sunday, followed by a cold front Sunday evening.

Most terminals lower to IFR tonight with the exception of most of
the city terminals. -Shra overnight, then still a chance of a few
showers Sunday morning through early afternoon, but will leave it
out for now. Better chance of showers and thunderstorms with a
convective line somewhere between 21z-02z, depending on location.
Improving back to VFR otherwise during Sunday morning with VFR
prevailing outside of any showers/thunderstorms.

S-SW winds 10-15 kt with winds diminishing a little overnight. Winds
are expected to become more SW Sunday morning, increasing back to 10-
15 kt. Occasional gusts around 20kt in the afternoon. Much stronger
gusts possible if afternoon/evening thunderstorms materialize

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

KTEB and KEWR possibly lowers to IFR for a few hours late tonight.
IFR start/end timing may be off by 1-2 hours for KLGA.
End timing of IFR for KJFK may be off by 1-2 hours. Occasional or
frequent gusts around 20kt possible Sunday afternoon. Much stronger
gusts possible if afternoon/evening thunderstorms materialize.

OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...

Sunday evening: Sub-vfr in TSRA potential early on, then VFR returns
by midnight.

Monday through Wednesday: VFR.

Thursday: Mainly VFR, with possible sub VFR later in the day and at
night in possible SHRA or TSRA.

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

&&

.MARINE...
SCA on the non-ocean has been cancelled. The SCA remains on
South Shore Bays and ocean through Sunday early evening with
other waters staying mainly below SCA criteria. The ocean has
SCA remaining through all of Sunday evening. Sub-SCA conditions
expected Sunday overnight into early Monday. In terms of
specially seas, just the ocean meets the SCA criteria through
Sunday evening with other waters staying well below SCA
thresholds for seas. Any SCAs for non- ocean waters are due to
gusty winds near 25 kt.

Winds and waves are expected to remain below SCA criteria from
Monday through Friday. However, late day winds in the NY Bight area
just E of Sandy Hook could gust close to 25 kt both Wed through Fri
afternoons.

&&

.HYDROLOGY...
No hydrologic issues anticipated into Sunday morning.

Minor flooding more probable Sunday afternoon and evening with
thunderstorms. Localized flash flooding cannot be ruled out.
Total rainfall amounts through Sunday evening between a half to
1 inch, with locally higher amounts possible.

Locally heavy rainfall may be possible Thu night into Fri with a
passing frontal system.

&&

.TIDES/COASTAL FLOODING...
The rip current risk is high this afternoon and evening with
strengthening SE winds and building seas.

The high risk continues into Sunday with swells of 5-6 ft and 7
second period.

The high risk continues into Monday morning, but it looks like
most beaches will transition to moderate from late morning
onward.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents through Sunday evening for NYZ075-080-
     081-178-179.
NJ...None.
MARINE...Small Craft Advisory until 8 PM EDT Sunday for ANZ345.
     Small Craft Advisory until midnight EDT Sunday night for
     ANZ350-353-355.

&&

$$

SYNOPSIS...JM/JP
NEAR TERM...DS
SHORT TERM...JM
LONG TERM...JP
AVIATION...JC
MARINE...JM/JP
HYDROLOGY...JM/JP
TIDES/COASTAL FLOODING...