Area Forecast Discussion
Issued by NWS Upton, NY

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377
FXUS61 KOKX 161550
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1150 AM EDT Tue Jul 16 2024

.SYNOPSIS...
A surface trough will remain in place today. A cold front
approaching from the west on Wednesday will move through late
Wednesday night into Thursday morning. High pressure will then
follow for late week, and remain nearby into the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Fcst on track so far. Another hot and humid day ahead.

Guidance consensus progs H85 temps 21 or 22C today, yielding
surface temperatures into the 90s once again for most areas with
sufficient mixing of the BL. Some of the warmest locales in
urban NE NJ may touch triple digits. Increasing SW flow should
allow dew pts to fall into the upper 60s this afternoon. With
these values, heat indices approach or exceed 100F across much
of the region once again this afternoon. Heat Advisory remains
in place today for all but SE Suffolk and coastal New London.

Then into this afternoon, yet another mid level shortwave in the
flow approaches, and CAMs depict clusters of convection developing
along with it into the evening given a modestly unstable air mass.
Forecast soundings peg DCAPE values near 1000 J/kg over the
LoHud Valley, and with effective shear toward 30 kt, should be
sufficient to support organized cells and line segments capable
of producing strong wind gusts. Any potential convective debris
clouds would probably occur late enough in the day to limit the
impact on potential high temperatures or heat indices. Timing
looks late afternoon for far western parts of the region,
working into NYC and metro by early evening, and points east
into the evening as activity likely weakens with loss of
heating. SPC has expanded their slight risk to include much of
the region, with a marginal risk for Long Island and SE CT.
With a moist environment to work with, torrential downpours are
possible with any thunderstorm and could lead to flooding,
primarily of urban and poor drainage areas.

Conditions dry out tonight with another very warm and humid
night expected. Low temps will be near 80 in NYC and in the
mid/upper 70s most elsewhere.

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
One more afternoon of hazardous heat and humidity across much of
the region Wednesday before a respite. Digging trough will
push a cold front toward the region, instigating convection once
again in the afternoon and evening. Ahead of it, temperatures
climb into the upper 80s to mid 90s, and heat indices likely top
out between 95 and 100. Extended the Heat Advisory thru
Wednesday for all areas but SE Suffolk and coastal New London
with increased confidence in coverage of these values.

Showers and thunderstorms become likely by late afternoon for
western areas, spreading east and persisting thru the evening,
before the fropa is expected to move through overnight into
early Thursday morning. SPC has outlined a slight risk for the
LoHud Valley, NE NJ, NYC, and western Long Island, with a
marginal risk farther east. Damaging winds will be the primary
hazard, though torrential downpours with this activity could
lead to flooding. The 00Z HREF highlighted a low (10%), but non
zero, chance of some areas recording 3 inches in 3 hr, which can
be a good signal for a heavy rainfall potential. More likely
though, is a lower end nuisance type flooding. The showers and
storms likely linger overnight, gradually ending from west to
east working into Thursday.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
The main story for the long term will be relief from the high
heat and humidity that currently persists over the region.

Key Points:

* A cold front will continue working offshore on Thursday. A few
  showers, possibly a thunderstorm may linger nearby in the
  morning with dry conditions becoming likely in the afternoon
  and evening.

* Daytime temperatures will return to near seasonable levels
  Thursday and Friday with dew points falling into the lower and
  middle 60s, potentially upper 50s in spots.

* A slight moderating temperature trend is possible for the
  upcoming weekend, but highs will still be in the middle to
  upper 80s with dew points in the 60s.

* Mainly dry conditions should persist into the upcoming
  weekend.

Upper level trough will continue over the region on Thursday
with the cold front pushing offshore. The deep moisture axis
and main area of forcing follows, but there could be some
lingering showers in the morning, especially closer to the
coast. A thunderstorm is possible, but instability will be
diminishing as the front pushes further offshore. Model trends
continue supporting the end of any showers Thursday afternoon
and have trended PoPs lower than the latest deterministic NBM.

The upper trough axis will likely swing across the area Thursday
night into Friday morning. Broad troughing will then persist
aloft into the start of the weekend, with a more amplified
trough passage late in the weekend. The main uncertainty will be
how much moisture will be able to return to the region. Forcing
continues to look weak, but there is a signal for a weak
surface trough or front nearby which could be a mechanism for
convection. The deepest moisture and more organized forcing
stays largely north. Will continue to keep the forecast dry
through the weekend/next Monday, which is in line with the
latest model consensus.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
A surface trough will remain nearby into tonight.

VFR through at least early afternoon with SW winds 5-10kt
backing more southerly for the afternoon and increasing 10 to
around 15kt with gusts 20-25kt. Winds and gusts, especially
along the coast will be a few knots higher during the afternoon.
Changed the PROB30s to TEMPOs for TSRA, and adjusted the timing
an hour later. There is a chance that any late afternoon storms
will have stronger westerly gusts, and added to the inland
terminals.

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

Timing of convection may be off by a couple of hours. Iso
shra/tstm possible for an hour or two on either side of TEMPO
timing.

Chance that winds back about 20 degrees more than currently
forecast this afternoon ahead of the potential convection.

OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY...

Wednesday: MVFR or lower in showers and thunderstorms during
the afternoon and evening, with still a chance of showers and
thunderstorms later at night.

Thursday: Mainly VFR. Chance of showers and thunderstorms mainly
in the morning.

Friday and Saturday: VFR.

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

&&

.MARINE...
Hoisted SCA for the ocean waters and Long Island south shore
bays, as near shore gusts via combo of an enhanced sea breeze
and Ambrose jet increase to 25-30 kt late today into this
evening. Ocean seas are already nearing 4 ft, and with synoptic
scale flow increasing to near 20 kt seas of at least 5 ft late
likely tonight into Wed morning.

Advisory conditions are again likely on the ocean waters late
day Wed as seas build to 5-7 ft ahead of an approaching cold
front. These elevated seas may linger into Thu afternoon.

&&

.HYDROLOGY...
With a humid air mass in place, any thunderstorms that develop
through Wed night will have the potential to produce downpours
capable of causing at least minor urban and poor drainage flooding.

No hydrologic impacts are anticipated Thursday through the
upcoming weekend.

&&

.TIDES/COASTAL FLOODING...
Strong rip currents were occurring at most of the ocean beaches
via combo of low tide and 3-4 ft S swell. With onshore flow
increasing this afternoon to 25-30 kt will follow RCMOS and
upgrade to a high risk for all ocean beaches but eastern
Suffolk.

Seas near 5 ft and a 15 kt flow support a high rip current risk
for Wed as well.

&&

.CLIMATE...

Daily record high temperatures for today (fcst temps at most
sites may get close):

 ...TUE JUL 16...

Newark:       101/1988
Bridgeport:    95/2013
Central Park:  99/1980
LaGuardia:     97/1980
Kennedy:      100/1983
Islip:         95/1983

Daily record high minimum temperatures for the next couple of
days:

 ...TUE JUL 16...

Newark:        80/1983 (still in jeopardy of being tied or broken)
Bridgeport:    75/2013
Central Park:  80/1952
LaGuardia:     81/2021
Kennedy:       81/1983
Islip:         76/1983

 ...WED JUL 17...

Newark:        80/1968
Bridgeport:    77/1968
Central Park:  82/1870
LaGuardia:     79/1999
Kennedy:       79/2013*
Islip:         75/2021*

* = also in previous years

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory until 9 PM EDT Wednesday for CTZ005>011.
     Air Quality Alert until 11 PM EDT this evening for CTZ005>007-
     009>011.
NY...Heat Advisory until 9 PM EDT Wednesday for NYZ067>075-078>080-
     176>179.
     Air Quality Alert until 11 PM EDT this evening for NYZ067>075-
     176-178.
NJ...Heat Advisory until 9 PM EDT Wednesday for NJZ002.
     Air Quality Alert until 11 PM EDT this evening for NJZ002-004-
     006-103>108.
     Heat Advisory until 10 PM EDT Wednesday for NJZ004-006-103>108.
MARINE...Small Craft Advisory from 6 PM to 11 PM EDT this evening for
     ANZ345.
     Small Craft Advisory from 6 PM this evening to noon EDT
     Wednesday for ANZ350.
     Small Craft Advisory from 6 PM this evening to 9 AM EDT
     Wednesday for ANZ353.
     Small Craft Advisory from 4 PM this afternoon to 2 AM EDT
     Wednesday for ANZ355.

&&

$$

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