489
FXUS61 KOKX 231929
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
329 PM EDT Wed Jul 23 2025
.SYNOPSIS...
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Bermuda high pressure exerts control through early Friday. A
cold front moves through the area Friday evening into Friday
night. High pressure briefly builds in behind the cold frontal
passage Saturday, before another frontal system moves through
Sunday.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH TONIGHT/...
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Upper ridge axis noses through the region tonight with
moderating Canadian high pressure sliding offshore.
Dry with near seasonable temps and still comfortable Tds
tonight.
Overnight lows will be a few degree warmer than last few nights
(mid 60s to around 70s) for most of the area, but could still
radiate to around 60s across pine barrens and interior valleys.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
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Key points...
* Heat alerts in effect for Friday. One day of 100 to 105F heat
indices expected for most of the area Friday
* Isolated to scattered severe thunderstorms possible Friday
aft/eve, with damaging wind gusts the primary threat.
Increasingly hot and humid conditions are expected during the
short term period.
Upper lever ridge nosing into the region on Thursday, flattens
Thursday Night into Friday, as a northern stream shortwave
slides from Ontario/Quebec towards northern New England. At the
surface, moderating Canadian high pressure continues to slide
offshore and get absorbed into larger Bermuda high on Thursday.
Return flow strengthens on Thursday as Bermuda high takes
control. WAA and moisture advection is gradual on Thursday, with
peak axis of heat and humidity not reaching the area until
Thursday Night Friday from the NW, 850 mb temps raining to about
17c by late afternoon, in a deeply mixed S/SW flow. Away from
coast, with deep mixing, this should allow temps to rise into
the lower 90s, but with TDs in the mid to upper 60s, heat index
will likely remain similar and peak out in the lower 90s range
for NE NJ, northern NYC, W LI, LoHud and SW CT. Closer to the
south facing coasts, maritime influence will likely cap temps
in the mid 80s.
Increasingly warm and muggy Thu Night in gusty S/SW flow, with
lows in the 70s.
Peak heat and humidity continues on target for Friday with peak
axis of heat (850mb temps of near 20c) sinking SE towards the
region and likely moisture pooling ahead of approaching cold
front (lower 70s to 75F Td) resulting in heat indices in the
lower 100s to 105F for much of the area. Moderate confidence in
widespread 105 F heat index coverage across NE NJ (have issued
extreme heat watch), with low to moderate confidence elsewhere
(heat advisory issued). With moderate to high confidence in
extreme to near extreme heat potential have issued respective
heat alerts to compliment messaging of one day of intense heat
and humidity, allowing subsequent shifts to follow td trends and
make decision on heat advisory vs extreme heat warning.
In addition to the extreme heat threat, a cold front will be
pressing down on a moderately to highly unstable airmass, with
marginal deep layer shear presenting potential for isolated to
scattered severe thunderstorms in the late aft/eve. Limiting
factor for organized convection will be weak shortwave forcing
this far south, as compared to central and northern New England,
and weak mid-level lapse rates. Main conditional threat will be
damaging wind gusts from wet downbursts in primarily a uni-
directional WNW flow aloft, high PWAT environment with a bit of
mid-level dry air entrainment potential, and steep low-level
lapse rates. This forecast will be refined as we get closer to
the event, and more confidence on synoptic and mesoscale
details.
Cold front expected to push SE of the region by midnight Friday
as northern stream shortwave slides through northern New
England, with a cooler and drier airmass filtering in its wake
as high pressure builds into the region.-- End Changed Discussion --
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
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Surface high pressure quickly builds in behind a cold fropa and
briefly settles over the region to start the weekend. The resultant
flow ushers in a slightly cooler, drier air mass, offering some
limited relief from the heat and humidity.
Air temperatures and dew pts fall about 5 degrees relative to
Friday, alleviating the peak of the heat, but afternoon highs likely
still top the mid to upper 80s. With slightly lower humidity, heat
indices are progged near or just above air temps, and an extension
of the heat headlines appears unlikely at this time.
Meanwhile, Southeast ridging remains anchored in place through early
next week. A short wave disturbance rides over the ridge and through
New England on Sunday, with the associated frontal system tracking
through the local area. Showers and thunderstorms likely accompany
the system at some point during the day, dependent on the surface
features placement and timing, which some disagreement amongst
global models will need to be resolved before pinning down.
Conditions dry out once again Monday and Tuesday, with another
frontal boundary approaching from the west into mid next week.-- End Changed Discussion --
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
High pressure moves offshore today and remains offshore into
Thursday.
VFR through the forecast period.
Winds generally S at 7-12kt this afternoon. Some enhancement to
15kt possible along the immediate coast. A few gusts up to 20
kt are possible this afternoon, however, not confident enough in
frequency and occurrence to include in the TAFs. Winds become
light SW to light and variable tonight. Winds pick back up out
of the SSW after 12Z Thursday and increase to 10-15kt with gusts
up to 25kt possible.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
A few gusts up to 20 kt possible at KEWR, KTEB, and KLGA this
afternoon.
.OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
Thursday: VFR. South winds G20-25kt, highest at the coast.
Friday: VFR likely through morning, possibly followed by periods of
sub VFR in showers and thunderstorms for the afternoon and
evening. Southwest winds G15-20kt.
Saturday: VFR with widely scattered showers and thunderstorms
during the afternoon and at night possible.
Sunday: Mainly VFR. MVFR or lower possible in any showers or
thunderstorms.
Monday: Mainly VFR.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
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Sub Small Craft Advisory conditions expected for the most part
through Thursday AM. Marginal 25 kt gusts are possible in a
S/SW flow late on Thursday aft into Thursday Night on the ocean
waters and southern bays, and possibly Fri aft/eve ahead of a
cold frontal passage.
Showers and thunderstorms are possible ahead of the cold frontal
passage Friday afternoon through the evening. There is potential for
some of these to be severe.-- End Changed Discussion --
&&
.HYDROLOGY...
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Localized minor urban and poor drainage flooding is possible
with isolated to scattered thunderstorm activity Friday aft/eve.
Showers and thunderstorms associated with a frontal system could
produce locally heavy downpours on Sunday that result in mainly an
minor urban and poor drainage flood threat with a low and localized
flash flooding threat.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
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With continued southerly flow on Thursday, a solid moderate risk
anticipated with southerly wind waves building to 3 ft, residual 1-2
SE wind swell, and a wide tidal range with approach of new moon.
There is potential for a late day high rip current risk across
Nassau and Queens beaches with late day coastal jet development.
A moderate to high rip current risk is likely on Friday with
southerly wind waves building to 3 to 5 ft, and a wide tidal range
with recent new moon.-- End Changed Discussion --
&&
.CLIMATE...
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Daily record high temps maybe be approached on Friday July
25th. Current high temp records for the day ...
EWR 99/2016
BDR 93/2001
NYC 97/1999
LGA 97/1999
JFK 93/2010
ISP 94/1987-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Heat Advisory from 11 AM to 8 PM EDT Friday for CTZ005>011.
NY...Heat Advisory from 11 AM to 8 PM EDT Friday for NYZ067>075-
078>080-176>179.
NJ...Heat Advisory from 11 AM to 8 PM EDT Friday for NJZ002.
Extreme Heat Watch from Friday morning through Friday evening
for NJZ004-006-103>108.
MARINE...None.-- End Changed Discussion --
&&
$$
SYNOPSIS...DR/NV
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...DR
AVIATION...MW
MARINE...DR/NV
HYDROLOGY...DR/NV
TIDES/COASTAL FLOODING...NV
CLIMATE...NV