231
FXUS61 KPHI 260903
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
503 AM EDT Sat Jul 26 2025

.SYNOPSIS...
A cold front continues sinking south across the area early this
morning as weak high pressure builds over New England. This
front will lift back north as a warm front on Sunday, ahead of
another cold front that will pass through later Sunday into
Sunday night. High pressure returns for Monday and Tuesday,
before yet another front passes through Wednesday into Thursday.
High pressure returns to close out next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
A cold front continues to push southward across the area early
this morning but will tend to stall out as it reaches southern
Delmarva. The front then takes on a more back-door orientation
as we get into the day today as the winds in its wake shift to
easterly around 5 to 10 mph. This should bring a more stable and
overall more pleasant day, but dew points likely remain in the
70s across Delmarva. 60s dew points should reach Philly and some
parts of northern NJ might drop into the upper 50s. However,
with the front nearby there will be some showers and
thunderstorms developing in the afternoon over central and
western PA and a few of these could reach our southern/western
border by late day. Otherwise the day should be mostly free of
precipitation with variable cloudiness. Highs mostly in the 80s
with heat indices ranging from the upper 80s north to the 95 to
100 range over our southern Delmarva zones.

As we get into the evening and overnight period, there will be
increasing chances for showers and thunderstorms, especially
over our eastern PA zones. The first round of scattered
diurnally driven storms will likely weaken through the evening
over eastern PA but then overnight another round of
showers/storms will be possible as an upper level disturbance
approaches from the west. Our highest POPs will again be over
eastern PA as POPs ramp up to 50-70 percent overnight. In terms
of hazards, severe weather is unlikely but with PWATs that will
be around 2.25+ inches heavy rain and localized flooding will be
possible from around the urban corridor and points north/west.
Dew points will also start to creep back up as the winds turn
more southerly. Expect lows ranging from the middle to upper 60s
over the southern Poconos and NW NJ to the low 70s over SE PA,
southern NJ, and Delmarva.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Overall, the forecast for Sunday and Sunday night remains
largely on track as it still looks to be the more active day of
the weekend as another low pressure system impacts the area
with a more pronounced shortwave aloft traversing across New
England. This will lead to a warm front lifting north across the
area early on Sunday before a cold front tracks through the
area later Sunday into Sunday night. After the convection from
Saturday night diminishes and moves offshore, there should be a
lull at least in the morning hours before a second round of
convection develops in the afternoon ahead of the cold front.
However, sunshine and instability looks rather limited as there
isn`t anticipated to be much clearing in between the two
impulses. As a result, there is not anticipated to be much (if
any) of a severe weather threat, instead, this looks to be more
of a hydro threat given that PWATs will be in excess of
2.0-2.5". Meaning, that any given shower or thunderstorm will be
capable of highly efficient rainfall rates. However, storm
motion should be relatively quick as the front approaches, so
looking at localized instances of flash flooding possible. WPC
has maintained the MARGINAL risk for excessive rainfall for our
entire area as a result. Convection will begin to wane into
Sunday evening as the cold front crosses through the area later
Sunday night. High temperatures will be in the 80s with lows in
the 60s and 70s.

High pressure then begins to build in on Monday with dry
conditions expected. Temperatures begin to warm again too though
with highs in the upper 80s to low 90s expected with lows mainly
in the 70s Monday night.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Little changes were made to the long term period as conditions
remain hot & humid through the mid-week whereas the late part of
the week will be seasonably cool.

Tuesday will feature increasing heat and humidity causing
chances for diurnal showers and thunderstorms to develop in the
afternoon, especially north and west of the urban corridor. By
Wednesday, another cold front looks to be on the horizon,
crossing through the area later Wednesday night. This will bring
a more widespread opportunity for showers and thunderstorms to
the area. However, some guidance is slowing down the progression
of the front, delaying the arrival of showers and storms until
later on Wednesday. If this were this case, this would diminish
chances for severe weather. Otherwise, the Tuesday through
Wednesday period will feature heat indicies around/in excess of
100 degrees, so will likely need to evaluate potential heat
headlines for these days. As of now, the `worst` day in terms of
heat looks to be Tuesday.

By Thursday, the front looks to be south of the region but with
a slower profession, may continue to linger near the region,
resulting in continued chances for rain through Thursday night.
By Friday, should begin to see some improvement around the area
as the cold front moves offshore and strong high pressure sets
up over the Great Lakes resulting in dry conditions. Even so,
with the front south of the area by Thursday, a much cooler and
refreshing airmass from Canada looks to arrive, where our
temperatures are expected to be as much as 5-10 degrees below
average to end the week.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today...Primarily VFR, though a few showers and isolated
thunderstorms possible (20-30% chance) in the afternoon at
around the I-95 TAF sites and points N/W. Given low chances and
low confidence, we continue to keep any mention of thunder out
of the TAFs. Winds out of the E/NE in the morning around 5-10
kt, becoming SE in the afternoon, still around 5-10 kt. Moderate
confidence.

Tonight...Mainly VFR through the evening with increasing
chances for some restrictions overnight as chances for showers
and thunderstorms increase and there may also be a low stratus
deck that forms. Winds SSE around 5 knots. Moderate confidence.

Outlook...

Sunday through Sunday night...Mainly VFR conditions expected
with sub-VFR conditions probable at times with periods of
showers and thunderstorms.

Monday through Monday night...VFR. No significant weather expected.

Tuesday through Wednesday...Primarily VFR with localized times of
sub-VFR conditions. A chance for showers and thunderstorms on
Tuesday and especially later on Wednesday.

&&

.MARINE...
No marine headlines are expected through tonight though
northeast winds could gust to around 20 knots as we get into the
day today. Seas generally around 2 to 3 feet through the
period.

Outlook...

Sunday through Wednesday...No marine headlines expected. Winds
should largely remain 15 kt or less with seas around 2-3 feet. A
chance for showers and thunderstorms expected on Sunday and
later on Wednesday. Otherwise, fair weather.

Rip Currents...

For Saturday, the surface winds become northeast to east 10 to
20 mph. Breaking waves in the surf zone will average around 1
to 2 feet. Even with the lower wave heights, I elected to go with
a MODERATE risk given the onshore flow even with a period of 5
to 8 seconds. Winds are lighter and seas are lower at the
Delaware Beaches. Thus, a LOW risk for rip currents is in place
for Delaware.

For Sunday, flow turns more southerly but light, only around 5
to 10 MPH. Seas decrease and breakers of around 1 to 2 feet are
expected. Period will remain 5 to 8 seconds. As a result, a LOW
risk for rip currents is in place at all beaches.

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

&&

.TIDES/COASTAL FLOODING...
Due to the new moon occuring on July 24, some spotty minor
coastal flooding may occur again with the high tide tonight
into Sunday. The most likely locations for any spotty minor
tidal flooding are along the Delaware Bay, as well as around
Cape May. No coastal flooding is anticipated along the
northeastern portion of Chesapeake Bay.

&&

.CLIMATE...
Record highs for July 25th were tied at Reading and Trenton
with record highs broken at Allentown and Philadelphia. Rain
cooled air will make it hard for any record high maximums to be
set for July 26th.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.

&&

$$

SYNOPSIS...AKL
NEAR TERM...Fitzsimmons
SHORT TERM...AKL/Fitzsimmons
LONG TERM...AKL/Fitzsimmons
AVIATION...AKL/Fitzsimmons
MARINE...AKL/Fitzsimmons/Guzzo
TIDES/COASTAL FLOODING...
CLIMATE...