127
FXUS61 KPHI 141100
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
700 AM EDT Tue Jul 14 2026

.WHAT HAS CHANGED...
Extreme Heat Warning issued for the urban corridor and adjacent
areas of central and southern New Jersey. Heat Advisory issued
for portions of the Eastern Shore of Maryland.

Small Craft Advisory issued for Atlantic coastal waters of New
Jersey north of Great Egg Inlet.

Aviation section updated for 12Z TAFs.

&&

.KEY MESSAGES...
1. Above normal temperatures beginning today and continuing
through the end of the week. Wednesday will be the hottest day
of the stretch, when dangerously hot and humid conditions are
expected. Extreme Heat Warnings and Heat Advisories are in
effect for our entire forecast area.

2. The weekend is shaping up to be active and unsettled with
chances for showers and thunderstorms each day. Some storms
could be severe and also may produce heavy rainfall leading to
flash flooding.

&&

.DISCUSSION...
KEY MESSAGE 1..Above normal temperatures beginning today and
continuing through the end of the week. Wednesday will be the
hottest day of the stretch, when dangerously hot and humid
conditions are expected. Extreme Heat Warnings and Heat
Advisories are in effect for our entire forecast area.

Heat and humidity will begin to build over the area today as an
upper level area of high pressure over the central part of the
country expands eastward towards the East Coast. This will
occur as a low pressure system moves through eastern Canada,
resulting in warm advection strengthening into Wednesday.

Highs today will generally range from the upper 80s to the mid
90s, but dewpoints and humidity will only be in the moderate
range so conditions are expected to stay below heat advisory or
warning levels. Maximum heat indices today will be in the mid to
upper 90s from around the Philly metro and north. However,
Wednesday will be a different story as the heat continues to
build over the area. High temperatures should range from the mid
90s to near 100 degrees in most areas, hottest along and
southeast of I-95, with increasing humidity. While some areas
will likely reach the century mark again, it will not be quite
to the magnitude that we experienced to start July. Humidity
will be a little less as well, and the hottest conditions will
only last for one day. However, heat index values are still
forecast to range from 100-109 degrees for most of the area,
again hottest from along and southeast of I-95. A modest
westerly, offshore wind near 10-15 mph should help keep the sea
breeze from making much inland progress during the afternoon
hours. Thus, we expect high temperatures in the mid to upper 90s
and heat indices near 100-105 degrees even for the New Jersey
Shore and Delaware Beaches.

A mostly dry cold front looks to pass sometime late Wednesday
which will knock down temperatures and dewpoints a bit, but
medium range guidance and ensembles indicate above normal
temperatures with highs ranging from the upper 80s into the
low/mid 90s could remain through the end of the week and
potentially into the weekend. The front should be mostly dry,
but would not be surprised to see a few isolated storms
developing along it late Wednesday afternoon and evening, mainly
across the Lehigh Valley, Poconos, and northern New Jersey north
of I-195. The latest HRRR and RAP guidance support near surface
smoke advecting in from the wildfires in western Ontario behind
the front as well, unfortunately. This will be preceded by smoke
and haze aloft beginning today, but not reaching the surface
until Wednesday from north to south as the day progresses. The
smoke could impact temperature forecasts.

Thursday will still be quite hot, with maximum heat indices in
the upper 90s to low 100s along and southeast of I-95. While we
aren`t explicitly forecasting advisory criteria to be reached,
it`s possible some additional Heat Advisories could be needed on
Thursday for our southern zones. Friday looks to bring more
relief from the humidity at least, as drier dewpoints advect in
from the north despite highs in the low to mid 90s remaining for
some areas.


KEY MESSAGE 2...The weekend is shaping up to be active and
unsettled with chances for showers and thunderstorms each day.
Some storms could be severe and also may produce heavy rainfall
leading to flash flooding.

We are still several days out, but are monitoring the severe
weather setup as we get into the weekend. At this point, the
cold front that comes through the area late Wednesday into early
Thursday looks to be mainly dry with just some spotty storms
possible over the southern Poconos into northern NJ late
Wednesday.

Another cold front will approach on Friday. Some models are
trending stormier with this period. For now though, the
consensus blend of guidance is still mostly dry through this
period, but will be watching trends within this period closely.

Regardless, most models are still focusing storm chances when
the front finally sinks into the region Saturday. The front will
stay over or at least near the region into Sunday. As is often
the case with these patterns following a building heat pattern
mid week, there is some potential for both severe threats and
heavy rain/flash flooding threat. At this early vantage point
the shear looks to be moderate to potentially strong with the
main question being how unstable it will get. This will
determine the extent of any severe weather threat but at this
point we see at least some potential for severe threats.
Precipitable water values will also be increasing to around 2+
inches. That is well about the 90th percentile for this time of
year, increasing the risk for heavy rain/flash flooding.

There`s uncertainty though regarding how fast this front pushes
through and also whether it may get hung up near the area into
early next week. If it moves through faster as the GFS is
indicating, things could start to clear out by later Sunday
afternoon with fair weather to follow for Monday. However the
ECMWF hangs up the front over the area into next Monday with
continuing chances for showers and storms.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today...VFR. Southwest winds increasing to around 10-12 kts by
16Z. Some gusts 18-20 kt possible. High confidence.

Tonight...VFR. Southwest winds 5-10 kts. High confidence.

Outlook...

Wednesday through Thursday night...Mainly VFR, however some
smoke moving in from the wildfires in western Ontario could
result in some MVFR visibility at times. Otherwise, no
significant weather.

Friday through Saturday...Restrictions will be possible in
isolated to scattered showers and storms. The chance for impacts
to terminals currently appears greatest Saturday afternoon and
evening.

&&

.MARINE...
South to southwest winds increasing as the day progresses to
near 15-25 kts, strongest north of Atlantic City. Seas building
3-5 feet. A Small Craft Advisory was issued for the New Jersey
Atlantic coastal waters north of Great Egg Inlet valid 2 PM to 2
AM. Winds and seas diminishing overnight.

Outlook...

Wednesday through Friday...No marine hazards expected. A few
thunderstorms possible Wednesday evening.

Saturday...Winds could get near advisory levels by the
afternoon.



Rip Currents...

For today, flow largely turns offshore with a 7 to 9 second
period swell. Wave heights remain around 2 feet or less as well,
resulting in a LOW risk for rip currents for most of the Jersey
Shore and Delaware Beaches. The exception is along the southern
New Jersey coast in Atlantic and Cape May counties, where south
facing beaches look to have some onshore flow in the afternoon
as winds turn back a bit more southerly with a sea breeze. Waves
in the surf zone look to increase up to 3 feet, and as a result
there is a MODERATE risk for the development of dangerous rip
currents for this area.

For Wednesday, flow looks to remain offshore all day across the
entire coast, with a 6 to 8 second period swell. Wave heights
will be around 2 feet or less, resulting in a LOW risk for rip
currents for all beaches.

For specific beach forecasts, visit weather.gov/beach/phi

&&

.CLIMATE...
A brief 1-day spike in temperatures is expected, with highs
likely to approach records. Here are the records for Wednesday,
July 15:

Allentown/ABE      98 in 1995
AC Airport/ACY    100 in 1995
AC Marina/55N      99 in 1995
Georgetown/GED     96 in 2024 and 1993
Mount Pocono/MPO   92 in 1954
Philadelphia/PHL  103 in 1995
Reading/RDG       100 in 1995
Trenton/TTN       101 in 1995
Wilmington/ILG     99 in 1997 and 1995

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Extreme Heat Warning from 10 AM to 8 PM EDT Wednesday for
     PAZ070-071-104-106.
     Heat Advisory from 10 AM to 8 PM EDT Wednesday for PAZ054-055-
     060>062-101>103-105.
NJ...Extreme Heat Warning from 10 AM to 8 PM EDT Wednesday for
     NJZ010-012>015-017>020-027.
     Heat Advisory from 10 AM to 8 PM EDT Wednesday for NJZ001-
     007>009-016-021>026.
DE...Extreme Heat Warning from 10 AM to 8 PM EDT Wednesday for
     DEZ001.
     Heat Advisory from 10 AM to 8 PM EDT Wednesday for DEZ002>004.
MD...Heat Advisory from 10 AM to 8 PM EDT Wednesday for MDZ012-015-
     019-020.
MARINE...Small Craft Advisory from 2 PM this afternoon to 2 AM EDT
     Wednesday for ANZ450>452.

&&

$$

DISCUSSION...Fitzsimmons/Hoeflich/Johnson/Staarmann
AVIATION...Staarmann
MARINE...AKL/Staarmann