208
FXUS61 KOKX 251938
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
338 PM EDT Fri Jul 25 2025

.SYNOPSIS...
High pressure slides east this morning. A cold front will move
through the area late this afternoon and evening. High pressure
briefly builds into the area tonight into Saturday. A weak frontal
system moves across the area Saturday Night into Sunday. High
pressure returns to the area for Monday into Tuesday. A cold front
approaches from the west on Tuesday afternoon and moves offshore
Tuesday evening.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Key points...

* Severe Thunderstorm Watch now in effect through 9pm

* Heat headlines remain in effect. Heat indices of 100 to 105F for
  most of the area, with locally up to 108F.

Northern stream shortwave slides from Ontario/Quebec towards
northern New England this evening with a cold front across W NY
pushing across the region this evening.

The combination of temperatures well into the 90s, combined
with dew points in the lower to middle 70s, will have widespread
heat index values of 100-105F continuing into early evening for
much of the area. Max temps will likely flirt with daily
records through this afternoon. Heat alerts continue through
8pm.

Numerous discrete tstms (isolated severe) already developing
across NE PA, Central NY and central New England as convective
temps in the lower to mid 90s are being met. Pre-frontal trough
across Central NY/PA and outflow boundaries from ongoing tstm
activity. moving into a moderate to highly unstable airmass
with marginal deep layer shear, along with approaching weak
shortwave/vort axis, should allow for groups of these storms to
cluster and developing into a few bowing line segments moving
across the area. Severe thunderstorms watch in effect through
9pm to address this threat.

Primary threat will be damaging wind gusts from wet downbursts
(possibly a few bowing segments) in primarily a uni-directional
WNW flow aloft, high PWAT environment with some mid- level dry
air entrainment potential, and steep low-level lapse rates. 60
mph winds gusts likely, with isolated gusts to 70+ mph possible
where mature bowing segment develops. Isolated large hail
possible with right moving supercells in slightly veered low
levels with undirectional shear aloft.

In addition, any storms will be capable of producing heavy
rainfall. 0.4"/5min rate noted with one of the cells as it moved
over a mesonet, presenting a localized flash flood threat with
any storms repeating over a location. See hydrology section for
low and localized flash flood threat in a 2+ STD PWAT
environment ( 2 1/4"-2 1/2" PWATs).

Cold front expected to push SE of the region by 7-9pm this
evening as northern stream shortwave slides through northern New
England, with a relatively cooler and drier airmass filtering
in its wake as high pressure builds down from the north. Low
tonight into the lower to mid 70s along the coast and upper 60s
interior with Tds gradually falling into the mid to upper 60s.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
Region remain on northeast periphery of strong southern upper
ridge through the weekend, with subtle ridging nosing in on
Saturday giving way to a shearing central plain short wave Sat
Night into Sunday.

At the surface, this evening`s cold front slides well SE of the
region by Saturday morning, with surface high pressure building
in from the north and centering to the E of the region by Sat
Night.

Dry conditions expected on Saturday, with noticeably drier and
cooler airmass advecting in on gusty N/NE flow Saturday AM, and a
veil of high clouds in upper flow. Temps will still run slight above
seasonable with highs in the mid to upper 80s, and heat indices
similar.

Models in general agreement with a shearing Central plains
shortwave approaching Sat Night and moving across the area
Sunday. At the surface, this will have a warm front approaching
the area Sat Night but likely not cleanly moving through the
area till Sun aft with a trailing trough crossing the region in
the afternoon or evening. Models have had a hard time locking in
on the specific of this event for a few days, with likely
difficulty in resolving the synoptic development tied to
mesoscale convective activity. Seems to be some general
agreement in a weak wave of low pressure tracking across the
region Sun morning into afternoon, which would be a focus for
more widespread shower and thunderstorms activity and a low
flash flood and severe risk in a high shear and marginally
unstable airmass. Latest guidance has trended this wave north
of the region, which would limit severe/flash flood potential
in the morning, and keep it low and isolated in the aft/eve with
warm front/trough passage. This will be refined through the
weekend as the convectively modified shortwave gets better
sampled it resolved by high res CAMs.

Otherwise near seasonable temps for Saturday Night with
increasing humidity levels as return flow develops. Warm and
muggy for Sunday, but temps may remain below seasonable with
clouds and shra/tsra activity.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
No major changes were made to the long term with this update.

Key Points:

*High heat and humidity will return early next week, potentially
lingering into Wednesday. The peak of the heat currently looks to
occur on Tuesday with max heat index values 100 to around 105F.

*A few showers and thunderstorms are possible Tuesday afternoon and
evening with a weak cold front. The threat for showers and
thunderstorms continues Wednesday, potentially lingering into
Thursday as a stronger cold front moves into the area.

*Temperatures trend down to end the week with potential of below
normal temperatures. Humidity levels also should be much lower than
the first half of the week.

Good model agreement continues with a large upper ridge over much of
the central and southern CONUS dominating the weather pattern early
next week. The ridge builds towards the area Monday and Tuesday then
slowly gets pushed southward as a deep upper trough digs down from
southeast Canada to end the week. A series of shortwaves will move
across the northeast as the ridge weakens late Tuesday into the mid
week period.

850 mb temperatures nearing 18-21C early next week, peaking on
Tuesday, will result in max temperatures in the low to mid 90s
(upper 80s at the coast). Dew points will likely increase to the low
and mid 70s by Tuesday resulting in heat indices potentially as high
as the low 100s (upper 90s coastal areas). Heat headlines are likely
to be needed Monday and Tuesday. There is a bit more uncertainty
with the extent of the heat on Wednesday due to timing of the
aforementioned second cold front. This front passage may not occur
until Wednesday night or Thursday, which would potentially bring
another day of heat and humidity on Wednesday. The air mass then
cools significantly Thursday into Friday with the cold front pushing
to our south and east. The latest NBM deterministic indicates highs
in the upper 70s and lower 80s with dew points in the 50s by Friday.

A shower or thunderstorm is possible Tuesday afternoon/evening, but
the chances are a bit higher on Wednesday with the stronger cold
front. Model soundings indicate 500-1000J/kg of MUCAPE though shear
is weak (~20kts) on Tuesday. Shear increases on Wednesday and modest
instability may be present. CSU-MLP machine learning output is
highlighting a 15-30% chance of severe thunderstorms, mainly from
NYC north and west Tuesday. It also indicates a similar potential on
Wednesday although it is shifted from NYC metro on south and west.
These details will come into more focus over the next few days, but
the trend in the last 24 hours is leaning towards Wednesday with the
main cold front and more organized forcing for convection.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
A cold front passes through late this afternoon/evening, with
high pressure briefly following for Saturday.

VFR through much of the TAF period. MVFR or lower visibilities
are likely as TSRA may impact the terminals until around 22-23z.
Strong gusty winds are possible with any thunderstorm as storms
could reach severe levels. Have kept TEMPO groups for TSRA and
added enhanced wording for gusts for some sites given strong to
severe cells currently being observed. Also given the slightly
earlier start time have moved up the end time of TSRA.

SW winds around 10 kt become NW behind the frontal passage in
the late afternoon/evening. Winds then veer overnight into
Saturday becoming SE by Saturday afternoon around 10 kt.
Occasional gusts up to about 20 kt are possible during this
afternoon outside of TSRA.

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

Occasional gusts up to 20 kt are possible this afternoon outside
of thunderstorms.

Severe thunderstorms are possible this afternoon/evening. Strong
to damaging wind gusts are the biggest threat should a severe
storm develop. Large hail looks like less of a threat.

.OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...

Saturday: VFR.

Saturday night - Sunday: Mainly VFR. MVFR or lower possible in any
showers or thunderstorms.

Monday: VFR.

Tuesday - Wednesday: Mainly VFR with possible MVFR or lower in
showers and thunderstorms each afternoon.

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

&&

.MARINE...
Some occasional gusts to 25 kt are possible in a S flow on ocean
waters and southern bays of LI this afternoon/evening ahead of
a cold frontal passage. Scattered severe thunderstorms are
likely late this afternoon and this evening ahead of a cold
frontal passage this evening.

A brief period of 20 kt gusts are possible in wake of cold
frontal passage Friday night into Saturday morning.

A relatively weak pressure gradient Monday through Wednesday will
lead to conditions staying below SCA levels.

&&

.HYDROLOGY...
Primarily a minor urban and poor drainage flooding threat with
thunderstorm activity this afternoon that could produce rainfall
rates of 2+"/hr with PWATS as high as 2"-2 1/2", but will be
overall progressive limiting duration over an one area. Based on
these rainfall rates, there is a localized flash flood threat
with any repetitive thunderstorm activity, particularly if the
cold front orients in a more W to E fashion as indicated by some
CAMs. A general 1/4 to 3/4" basin average, with a low and
localized probability for 2-3" in 1 to 2 hrs with any training.

Showers and thunderstorms associated with a frontal system
could produce locally heavy downpours on Sunday that present a
minor urban flooding threat, with localized flash flood threat
appears low at this time.

There are currently no hydrologic concerns next week.

&&

.TIDES/COASTAL FLOODING...
A moderate to locally high rip current risk is in effect through
this evening with southerly wind waves building to 3 to 4 ft. A
moderate rip current risk continues for Saturday, though surf
heights lessen to 2-3ft and winds become east/southeasterly.

&&

.CLIMATE...
Daily record high temperatures maybe be tied or broken today
July 25th. Here are the current records for the day...

EWR 99/2016
BDR 93/2001
NYC 97/1999
LGA 97/1999
JFK 93/2010
ISP 94/1987

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory until 8 PM EDT this evening for CTZ005>011.
     Air Quality Alert until 11 PM EDT this evening for CTZ009>012.
NY...Heat Advisory until 8 PM EDT this evening for NYZ067>075-
     078>080-176>179.
     Air Quality Alert until 11 PM EDT this evening for NYZ069>075-
     078>081-176>179.
NJ...Heat Advisory until 8 PM EDT this evening for NJZ002.
     Air Quality Alert until 11 PM EDT this evening for NJZ004-006-
     103>108.
     Extreme Heat Warning until 8 PM EDT this evening for NJZ004-
     006-103>108.
MARINE...None.

&&

$$

SYNOPSIS...DS/NV
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...DS
AVIATION...JT
MARINE...DS/NV
HYDROLOGY...DS/NV
TIDES/COASTAL FLOODING...
CLIMATE...