024
FXUS61 KOKX 121123 CCA
AFDOKX
Area Forecast Discussion...CORRECTED
National Weather Service New York NY
723 AM EDT Tue Aug 12 2025
.SYNOPSIS...
High pressure remains in control into tonight as it drifts south
off the East Coast. A cold front then approaches on Wednesday,
slowly moving through the region Wednesday night into Thursday
morning, and lingering nearby through the day Thursday. High
pressure then briefly returns Friday into Saturday before another
cold front passes through Sunday into Monday.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Mid-level ridging remains in place over the region today, with a
weak surface high pressure drifting south off the Mid Atlantic
coast. The nearby high maintains another day of dry and sunny
weather. With the exception of a cirrus veil, skies remain
abundantly sunny, with perhaps a bit of afternoon cu developing in
some locales west of the Hudson.
Warm air in place aloft, 850mb temps progged around 18-19C and
925 mb in the mid 20s, should allow most to achieve upper 80s or
lower 90s at the surface. A strengthening S/SW flow will lead to
a subtle increase in dew points by mid to late afternoon, making
for a more muggy feel to the air late in the day. Even with dew
pts into the upper 60s though, heat indices likely only near or
just above actual air temperatures with peak values into the
lower 90s.
Temperatures tonight will be slightly warmer than previous nights
with lows in the upper 60s to low 70s. Could see a bit more
coverage of fog or low stratus overnight into Wed AM relative to
previous nights.-- End Changed Discussion --
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Hot and humid air mass still in place Wednesday ahead of an
approaching frontal boundary from the west.
Ridging gradually breaks down and shifts east Wednesday as a trough
swings east through Canada. High pressure that was in place
offshore weakens and slides well south as a cold front gradually
approaches from the northwest. The persistent S/SW flow out
ahead of the front will maintain another day of heat and humidity
to the area. The national blend was followed for temperatures,
but blended in CONSALL to lower dew pts several degrees in the
afternoon with lingering dry air aloft and decent mixing toward
and 850 mb expected, but still could see dew pts get into the
low 70s, especially along the coast. Air temperatures will be
similar to the previous day, generally upper 80s to lower 90s
across most of the local Tri State, but the increased moisture
should lead to heat indices several above air temperatures, with
highest values into the mid to upper 90s, mainly across NYC, NE
NJ, and much of the interior. Thursday now appears to remain
warm and humid, but values likely decline a few degrees from
Wednesday with unsettled conditions in place around the nearby
front, and not confident we`ll see widespread 95F+ heat indices
both days. So while not out of the question a heat headline
could still be needed for portions of the region Wed/Thu,
forecast values at the moment do not warrant issuance of an
advisory with this update. More likely, peak heat indices into
the mid to upper 90s on Wednesday, and into the low to mid 90s
on Thursday, primarily away from the coast.
With the approach of the front and prefrontal trough, expect
scattered area of showers and thunderstorms to develop off to
the west and advance into the Lower Hudson Valley and NE NJ by
mid afternoon. While some modest instability and high PWATs
will be present, shear is relatively weak and best forcing is
located well north, so coverage and severity of any convection
appear relatively limited at this point. Best chance of a strong
to severe thunderstorm will generally be north and west of NYC,
where isolated damaging wind gusts will be possible into the
evening with any activity.
In addition, PWATs climb to near or over 2 inches, and with a
10kft warm cloud layer expected, efficient rain processes in
any thunderstorm could lead to locally heavy rainfall. Best
chances for this appear to be across the Lower Hudson Valley and
portions of NE NJ, which lines up fairly well with where WPC
has a marginal risk for excessive rainfall outlined. Outside of
the convective maxima however, QPF is low overall, generally at
or under a quarter inch, and anything more significant then
localized nuisance flooding appears unlikely.
The front looks to slow as it crosses the region, and may not fully
advance east until later Thursday morning. The nearby boundary keeps
PoPs elevated into Thursday afternoon, though not a washout, a few
additional showers or thunderstorms could develop at times.
Conditions begin to fully dry out Thursday night.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
No significant changes made and the NBM was followed for this period.
Brief high pressure builds in Friday into Saturday. It will still
remain on the warm side, but currently not anticipating temperatures
rising above the mid to upper 80s for most locations. The warmest
locations of NE NJ may touch or just exceed 90 both Friday and
Saturday. Dew points in the low to potentially mid 60s will keep max
heat indices from rising much above actual air temperatures.
The warmest day of the period will likely end up being Sunday.
Surface high pressure shifts to our east with the region ending up
on the periphery of a larger upper ridge dominating over the central
and southeastern states. A cold front is also likely to approach the
area in the afternoon and evening as a shortwave travels across
southeast Canada. Highs look to reach the upper 80s and lower
90s. NBM dew points have been running high in the extended and
it is possible that its current deterministic values in the
upper 60s and low 70s could be a bit high. Did not want to
change them as it is towards day 6 and we should have a better
idea of the lower level environment as we get closer. Currently,
heat indices may peak in the mid 90s in the warmest spots of NE
NJ and NYC metro.
The cold front brings a chance of showers and thunderstorms, but
probabilities are not higher than 20 percent. The front may have
limited forcing to work with and there is also uncertainty
surrounding when it will pass across the area, late Sunday or
Monday. Temperatures will trend cooler early next week.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
High pressure remains in control with mainly VFR conditions.
There is a chance for IFR-MVFR fog or ceilings tonight, mainly
across eastern Long Island and southeast Connecticut terminals.
Light SW or variable winds through 12z. SW winds increase after 12z
and shift towards the S late morning into the afternoon around or or
just over 10 kt. Winds will become SW this evening and decrease
overnight.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of wind shift to the S may be off by 1-2 hours this
afternoon.
Low chance for MVFR ceilings/visibilities late tonight/early
Wednesday morning.
.OUTLOOK FOR 12Z WEDNESDAY THROUGH FRIDAY...
Wednesday: MVFR-IFR ceilings/visibilities possible early east of
NYC terminals, then VFR into the afternoon. Chance of late
day/evening showers/thunderstorms with MVFR or lower. Chance of
showers late at night.
Thursday: Mainly VFR. Chance of showers and thunderstorms.
Thursday night-Saturday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
With a weak pressure gradient in place, winds and seas are expected
to remain below Small Craft Advisory (SCA) criteria through the
week.
&&
.HYDROLOGY...
Thunderstorms ahead of an approaching cold front Wednesday
afternoon and evening could produce locally heavy downpours
that result in minor nuisance flooding, especially areas west of
the Hudson River. The overall flood threat is low however.
There are no significant hydrological concerns through the
week.
&&
.TIDES/COASTAL FLOODING...
A moderate rip current risk remains in place today and
Wednesday along ocean beaches due to persistent E-ESE swells
with 2 to 3 ft waves and an 8 to 9 second period.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Air Quality Alert from 11 AM this morning to 11 PM EDT this
evening for CTZ005>012.
NY...Air Quality Alert from 11 AM this morning to 11 PM EDT this
evening for NYZ067>075-176-178.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...DR
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...DS
AVIATION...DS
MARINE...DR/DS
HYDROLOGY...DR/DS
TIDES/COASTAL FLOODING...