456
FXUS61 KOKX 151755
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
155 PM EDT Tue Jul 15 2025

.SYNOPSIS...
A weak front sags south of the area this morning, but remains
nearby through Wednesday as a Bermuda high remains anchored well
offshore. The boundary will lift north Wednesday Night, with a
trough moving through Thursday and then a cold front moves
through Thursday Night into Friday. This front remains just
south of the area through the weekend while high pressure
attempts to build. Another cold front moves through late Sunday
night into early Monday morning.

&&

.NEAR TERM /THROUGH TONIGHT/...
With shortwave upper ridging building in, and mid-level drying,
only an isolated shra/tsra threat in the aft/eve along
seabreeze boundary and higher terrain.

Seasonable temps (mid to upper 80s) and humid conditions (lower 70
Tds) continue today into tonight. Tds could end up being a bit lower
than forecast across interior based on mid-level drying and weak
offshore flow. This yields heat indices in the lower 90s to
around 95F across much of the region today. After collab with
neighboring offices have held off on heat advisory for today
with only marginal coverage of 95 HI for NYC and pts N&W, where
Tds could end up slightly lower than NBM deterministic.

Patchy stratus/fog development possible tonight/Wed Am in the moist
and weak flow environment.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Key Points:

* Moderate to high potential of 95F to low 100F heat indices (Heat
  Advisory) Wed thru Fri.

* Low to moderate potential for 105F heat indices (Extreme Heat
  Watch/Warning) on Thu.

Shortwave ridging surface/aloft slides east during the day on
Wednesday, with a southern plains shortwave approaching the
region Wed eve and crossing the area Wed Night.

At the surface weak high pressure on Wed will give way to an
approaching warm front Wed eve, pushing north of the region Wed
Night into Thu AM. A warm advective SW flow establishes around
Bermuda high with likelihood for start of a mid to late week
heat wave.

Between morning stratus and aft/eve convection a period of
partial clearing likely to lift widespread daytime temps in the
upper 80s to lower 90s, and Tds in the mid 70s. Widespread heat
indices in the upper 90s to lower 100s F likely. Potential for
105F heat indices appears low and sparse.

Scattered late day into overnight convection likely with passage of
southern shortwave and warm front. Isolated severe threat and
localized flash flood threat late Wed aft/eve for NYC and points
west in a moderately unstable and moist airmass. Convective
intensity should diminish overnight as it translates east, but
locally strong tsra and minor flood threat would still exist
with moistening profiles and marginal elevated instability.

Tri-State region is likely under an active zonal upper flow on
Thursday and in the midst of hot and very humid airmass on
Thursday on the periphery of Bermuda ridging and ahead of
approaching trough axis. With active flow aloft, convective
debris and timing/placement of pre-frontal trough axis and
convective initiation will be forecast challenges for amount of
sunshine. With that said, 850mb temps will be approaching 19c,
and with even limited sunshine supporting mixing to that level,
temps in the upper 80s and lower 90s are likely, with Tds
potentially pooling into the mid to upper 70s. This would yield
widespread heat indices of 100 to around 105F, presenting a low
to moderate potential for extreme heat watch/warning level.
Potential for aft/eve convection once again, with isolated
severe threat and localized flash flood threat Thu aft/eve for
much of the area in a moderately unstable and moist airmass.


Have stuck close to NBM deterministic T and Tds for Wed and Thu
based on convection and cloud cover timing challenges. NBM
deterministic also lies within a fairly tight 25 to 25th NBM
ensemble range for much of the area, outside of LI.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
***Key Points***

* Increasing likelihood for heat indices to exceed 95F Friday across
  much of the region.

* Unsettled pattern with chances for afternoon showers and
  thunderstorms continue for Friday. Saturday looks mainly dry, with
  better chances for showers and thunderstorms Sunday.

A slow moving cold front moves through on Friday, continuing
chances for showers and thunderstorms. The front remains south
of the area Saturday and much of Sunday before another front
approaches Sunday and moves through late Sunday night into early
Monday morning. With weak high pressure building in, much of
the area will be dry for Saturday, though an isolated shower or
thunderstorm cannot be ruled out mainly N and W of NYC. Another
cold front approaches for Sunday, giving the area better chances
for showers and thunderstorms late Sunday through the beginning
of next week with the front remaining nearby.

While nothing remarkable for mid July, temperatures
Fri likely top the upper 80s to lower 90s for most, and with dew
points forecast at least into the upper 60s and lower 70s, heat
indices should achieve mid to upper 90s.

One caveat may be the unsettled pattern, with showers and
thunderstorms possible each afternoon through late week with nearby
frontal boundaries, though the overall severe risk appears low.
However, deep layer moisture should keep PWATs near or above 2
inches, and with it, the potential for higher rainfall rates with
any convective activity.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
A weakening frontal boundary nearly stalls within the region
through Wednesday.

Pop-up showers this afternoon will be in vicinity of some
terminals, with perhaps a brief thunderstorm as well. In
addition, some brief MVFR is expected for this afternoon as well
for some terminals. Otherwise VFR conditions through early this
evening.

Then, for latter half of this evening, overnight into Wednesday
morning, low clouds and fog redevelop with a variance of
conditions across the region, mainly east of NYC terminals.
There will be increasing potential for MVFR to IFR.

Then, for Wednesday once the low clouds and fog decrease, VFR
conditions prevail again until showers and thunderstorms develop
mid afternoon into early evening Wednesday, presenting again
another chance for MVFR to possibly IFR conditions.

Winds overall mainly out of the south near 5-10 kts for much of
the TAF period.

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

Amendments possible for brief thunderstorm before 22Z.

Amendments likely to refine timing of fog overnight into early
Wednesday morning.

IFR possible for early Wednesday.

.OUTLOOK FOR 18Z WEDNESDAY THROUGH SATURDAY...

Wednesday-Thursday: MVFR or lower in any afternoon/evening
showers/thunderstorms.

Friday-Saturday: Mainly VFR.

Sunday: MVFR or lower with showers and possible thunderstorms.


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

&&

.MARINE...
Sub-SCA conditions through Thursday in a weak pressure regime,
although ocean seas will likely build to 3 to 4 ft late Wed into
Thu with persistent 15 to 20 kt S/SW flow, possibly around 5 ft
by Thu Night. Marginal SCA gusts possible Wed late aft/eve and
more likely Thu aft/eve with coastal jet formation.

A return to sub-SCA for Friday likely with offshore flow and
subsiding S swell in wake of cold frontal passage. Sub SCA conds
continue into the weekend with weak pressure gradient.

Otherwise, afternoon/evening showers/tstms through the period
could produce locally higher winds/seas at times.

&&

.HYDROLOGY...
Localized flash flood potential from scattered aft/eve
convection Wed thru Fri.

&&

.TIDES/COASTAL FLOODING...
The rip current risk is low today, with a mix of 1 ft SE swell
with 2 ft s wind waves.

After a low risk rip current risk to start on Wednesday likely
increases to moderate in the aft/eve with strengthening S flow
and building 2 to 3 ft S wind waves.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$

AVIATION...JM