858
FXUS61 KOKX 140855
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
455 AM EDT Mon Jul 14 2025

.SYNOPSIS...
A weak cold front approaches the region from the west today,
slowly moving through tonight and to the south Tuesday morning.
The frontal boundary likely dissipates just south of the area
midweek, allowing Bermuda ridging to exert more influence on the
area for mid to late week. A cold frontal likely moves through
the region this weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Points...

* Scattered to numerous instances of flash flooding possible
  across NE NJ and LoHud. Isolated to scattered instances of
  flash flooding possible for NYC and SW CT. Flood Watch in
  Effect from 2pm to midnight.

Shortwave trough axis over eastern Great Lakes/Ohio Valley this
morning slides east towards the region late this afternoon/evening
and slowly across the area tonight into early Tue Am, with a
weak surface trough across central NY/PA sliding east towards
the region this afternoon and across this evening into early Tue
AM.

Convection across the Poconos/Catskills should continue to wind
down early this morning as it traverses east into the Lohud/NE
NJ, but with a marginally unstable and moist airmass potential
for scattered heavy downpours/isolated convection for the early
morning commute well N&W of NYC. Otherwise, morning stratus and
fog should give way to breaks of sun in the afternoon,
particularly away from the immediate south coasts.

Daytime heating is expected to develop at least marginal
surface instability (locally moderate with more extensive breaks
of sun N&W of NYC). In a tropical environment with approaching
shortwave, this will be supportive of scattered tstm
development along outflow from decaying AM convection and sea-
breeze boundary to the N&W of NYC this afternoon, and then
scattered to numerous tstm development along/ahead of
approaching pre-frontal trough late this afternoon/evening.

Primary threat will be for torrential downpours from tstm
activity with 2+"/hr rainfall rates likely in a tall and narrow
CAPE profile environ, PWATS approaching 2.25" (+2 std), deep
warm cloud layer of 12-13kft, and weak SW steering flow (15kt)
aligned with trough/seabreeze/outflow boundary. Highest
coverage/confidence in this activity is across NE NJ and LoHud
in vicinity of sea-breeze/outflow convergence boundary and then
followed by approaching trough, with scattered to numerous
instances of flash flooding possible (15-25% prob w/i 25 miles
of a point). Farther east across NYC and SW CT, confidence in
coverage of convection is slightly lower (5-15% prob w/i 25
miles of a point prob) as sea-breeze/outflow activity likely
ends up to the N&W, with more organized trough activity late in
the day potentially weakening in intensity with waning
instability, although this could be counteracted by potential
increase in llj and shear/helicity with hints of weak surface
wave development. In any case, a lower confidence on flash flood
threat for this area, presenting more of an isolated to
scattered flash flood instance threat.

Weak low-level shear/helicity profiles and weak llj appear to
be a limitation for sustained updraft and backing-building
storms and a moderate flash flood threat for NE NJ/LoHUd, with
late trough approach and waning instability in the evening a
possible flash flood limitation for NYC and SW CT.

After collab with WPC and surrounding offices will issue Flood
Watch from 2pm to Midnight today for NE NJ, LoHud, NYC and
interior SW CT for above flash flood threat, with a widespread
1-3" of rainfall likely, and locally as high as 5", for NE NJ
and LoHud where most persistent/widespread convection is likely
based on predicted synoptic/mesoscale environment and CAM
output. HREF showing a 50% prob of 3"/3 hr across NE NJ, which
is a rare signal. Meanwhile, a widespread 1/2 to 1 1/2" of
rainfall is likely with localized rainfall totals of up to 3"
possible for NYC and SW CT. Most of this could fall in as little
as 3 hr period this aft/eve.

In addition, isolated strong to severe wet downburst possible
in marginally unstable airmass this afternoon as well, mainly
N&W of NYC.

Shortwave trough axis slowly slides east tonight into early
Tuesday morning, with weak surface trough axis sliding
southeastward through LI/CT. Convective coverage and intensity
will wane overnight into early Tue AM with waning instability,
but potential for locally heavy downpours and embedded tstm
activity to continue in vicinity of the trough and possible weak
wave development, particularly across NYC/LI/SE CT.

Seasonably warm and very muggy conditions today into tonight.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Key Points...

* Moderate potential for heat indices of 95-100F on Wednesday

Shortwave trough axis slowly slides east Tuesday morning, with weak
trough axis likely dropping south. Potential for locally heavy
downpours and embedded tstm activity in vicinity of the trough
across LI/SE CT Tue AM, then gradual mid-level drying
conditions expected Tue afternoon in wake. Low chance of
afternoon shra/tsra activity for NYC and pts N&W Tue aft during
peak heating.

Seasonable temps and very humid conditions continue Tue into
Tue Night. Patchy stratus/fog development possible Tue Night/Wed
Am in the moist and weak flow environment, particularly along
the coast.

Shortwave ridging surface/aloft should allow for more in the way
of sunshine on Wednesday, with warm advective SW flow
establishing around Bermuda high. Potential for start of a mid
to late week heat wave, with widespread daytime temps in the
upper 80s to lower 90s, and Tds in the lower to mid 70s.
Widespread heat indices of 95-100F possible. Late day/evening
convection possible with approach of southern shortwave/pre-
frontal trough.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Key Points...

*While still some uncertainty, there is the potential for a heat
wave to continue Thursday and Friday for many areas with max heat
index values between 95 and 105.

*Relatively active pattern with chances for several days of
afternoon showers and thunderstorms.

A frontal boundary will likely stall just offshore and linger,
possibly lifting north of the area Thursday. A frontal system may
then impact the area later in the week. Aloft, the pattern stays the
same through the period. Although we are under some high heights, we
are somewhat on the eastern end of a broad upper level trough
centered over central Canada and few shortwaves likely pass through.

With strong Bermuda high in place, a S/SW flow will allow plenty of
moisture to be sent our way. This combined with above normal high
temperatures brings some potential for a heat wave, with heat index
of 95-105 Thursday and Friday. However, there still is uncertainty
especially given the potential for convection and slight
inconsistencies in a late week frontal system among the guidance.

Too early to talk specifics when it comes to severe or flooding
concerns with the aforementioned convection. These details will be
ironed over the next few days. There is plenty of moisture around
with pwats 1.75-2.00+ for Thursday and Friday so any convection that
does develop will likely be able to produce heavy downpours. As for
severe, while we are pretty unstable, shear looks weak through much
of the period.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
A weak cold front gradually approaches the area today, crossing
tonight.

VFR to MVFR expected through daybreak today with IFR possible
towards daybreak, mainly for eastern terminals, but cannot be
ruled out even in for the metro terminals. Conditions improve to
VFR around midday today or into the afternoon at all the
terminals. There continues to be a lot of uncertainty with the
timing of flight change categories. Scattered showers will move
through, mainly for the metro terminals.

Showers and embedded thunderstorms across the Lower Hudson
Valley will move through KSWF between 10Z and 11Z this morning,
possibly a bit earlier. By that time, thunder is not expected,
but cannot be totally ruled out. Showers and thunderstorms are
then possible this afternoon. Higher confidence for the metro
terminals, KSWF, and KHPN with less confidence for eastern
terminals. Best timing is 22Z today through 02Z Tuesday, though
thunder may occur anytime after 18Z today. Thunder become less
likely after 02Z Tuesday, but an isolated thunderstorm may still
move through the terminals. Showers with heavy rain is more
likely, which will continue to reduce flight categories to MVFR
or lower through the remainder of the forecast period.

Light SE winds less than 10 kt through daybreak today. A more
southerly flow develops this afternoon with speeds to around 10
kt.


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

Amendments expected due to changes in flight categories changes
and timing through the forecast period.

Higher confidence in thunderstorms this afternoon at KEWR and
KTEB.


.OUTLOOK FOR 06Z TUESDAY THROUGH FRIDAY...

Monday Night: MVFR or lower in showers or thunderstorms.

Tuesday-Friday: Mainly VFR. MVFR or lower in any showers or
thunderstorms in the afternoon and evening.

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

&&

.MARINE...
With a weak pressure gradient, winds and waves likely remain
below Small Craft Advisory criteria through the coming weekend.
However, a relatively active pattern is expected next week with
chances of afternoon showers and thunderstorms for several days.
Winds and waves will be higher in any storms.

&&

.HYDROLOGY...
*Flood Watch issued from 2pm to Midnight today for NE NJ,
 LoHud, NYC and interior SW CT.

A widespread 1-3" of rainfall is likely, and locally as
high as 5", for NE NJ and LoHud where most persistent/widespread
convection is likely based on predicted synoptic/mesoscale
environment and CAM output. A widespread 1/2 to 1 1/2" of
rainfall is likely with localized rainfall totals of up to 3"
possible for NYC and SW CT. Most of this could fall in as
little as 3 hr period this aft/eve.

Highest coverage/confidence in this activity across NE NJ and
LoHud in vicinity of sea-breeze/outflow convergence boundary
followed by approaching trough with scattered to numerous
instances of flash flooding possible (15-25% prob w/i 25 miles
of a point).

Rainfall rates of 2+"/hr possible with stronger and/or
repetitive convection, which would cause localized instances of
severe flooding.

At this time, there are no significant flood concerns Tuesday
through next weekend.

&&

.TIDES/COASTAL FLOODING...
For Atlantic Ocean beaches, the rip current risk is low on
Today and Tuesday with generally a 10kt or less onshore flow
and a weakening S/SE swell.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Flood Watch from 2 PM EDT this afternoon through this evening
     for CTZ005-006-009.
NY...Flood Watch from 2 PM EDT this afternoon through this evening
     for NYZ067>075-176-178.
NJ...Flood Watch from 2 PM EDT this afternoon through this evening
     for NJZ002-004-006-103>108.
MARINE...None.

&&

$$

SYNOPSIS...JP/NV
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...JP
AVIATION...JP
MARINE...JP/NV
HYDROLOGY...JP/NV
TIDES/COASTAL FLOODING...