780
FXUS61 KPHI 120001
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
801 PM EDT Fri Jul 11 2025

.SYNOPSIS...
A very warm and humid airmass will persist over the region into
next week. Several disturbances will move through the area over
the course of the week, generating scattered showers and occasional
thunderstorms, especially in the afternoon and evening. A cold
front is on pace to cross through Monday night into Tuesday, with
high pressure potentially becoming more dominant later in the week.

&&

.NEAR TERM /THROUGH SATURDAY/...
An interesting spot of convection earlier in NE Monroe County PA
where a few nearly stationary tstms deposited 2 to 4 inches of
rain in about 2 hours. We had Flash Flood warnings out earlier
to cover this localized event. The showers have diminished for
most areas. A weakening area of showers/tstms may approached the
southern Poconos in a few hours, but with daytime heating over,
not much is expected with them.

Overnight, looks like with onshore flow we will once again see
either low clouds or fog overnight into the morning. Because
this marine layer is so shallow, it is not being well depicted
by coarser resolution models. Thus, favored high res models.
They suggest that this is more likely to be a low stratus than
fog event. However, given the uncertainty, kept a mention of
patchy/areas of fog started by the previous shift.

As the larger trough gets closer to our region tomorrow, more
convection is possible tomorrow afternoon. There is expected to
be a surface trough to our west tomorrow which may be the focus
for convective initiation. Thus, highest chances for storms are
in the southern Poconos, Berks Co, and Lehigh Valley, and then
chances decrease the further east you go.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
Any convection remaining should dissipate rather quickly into
Saturday evening with the loss of diurnal heating. The
combination of cloud cover, light onshore flow, and the moisture
rich airmass will continue to support the potential for some
low clouds/stratus and potentially fog to develop. Lows will
remain mild, mainly in the mid 60s to low 70s.

The environment looks to become a tad more active on Sunday as
there has been a subtle uptick in PoPs (30-60%) for Sunday
afternoon and evening. An upper level trough will be moving into
the Great Lakes, allowing stronger southwesterly flow to
overspread into the Mid- Atlantic and Northeast regions.
Although the best forcing will be displaced to our north and
west, the atmosphere should destabilize sufficiently with the
mild temperatures and high moisture content in place. SPC
maintains the MARGINAL risk for severe weather on Sunday over
our western most counties, where best atmospheric parameters
overlap with the better forcing. Outside of the MARGINAL risk,
more in the way of garden variety storms are possible, although
wouldn`t be surprised if most areas especially towards the coast
remain dry. Highs will mainly be in the mid to upper 80s with
heat indicies in the low to mid 90s. Convection should taper off
once again rather quickly with the loss of diurnal heating into
Sunday night, however a few showers or pockets of heavy rain
may make the trek into eastern Pennsylvania. Another mild and
muggy night is expected with lows similar to those on Saturday
night.

On Monday, the upper trough will move into the Eastern US but
will be weakening as it approaches. Although, the atmospheric
forcing will be closer to our area, the upper level support will
not be as strong as it will be on Sunday. This should keep the
overall nature of the potential for severe weather at bay.
However, with strong destabilization and some better forcing,
shower and thunderstorm activity will be more widespread
compared to Sunday; as PoPs are in the 60-80% range. Although,
the severe weather potential does not appear to be significant,
we can`t rule out a few strong to severe storms in the afternoon
into the evening hours with the cold front tracking across the
area late Monday night. Highs will mainly be in the 80s with
lows in the 60s/70s.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
For the long term period, there is quite a bit of uncertainty
with the evolution of the pattern. The cold front that tracks
through on Monday night will slow down and virtually stall over
or just south of the region on Tuesday while washing out. With
remaining surface convergence nearby, this may cause another
round of isolated showers and thunderstorms to occur on Tuesday.
By mid to late week, it does seem that Canadian high pressure
will try to take control over the Northeast while building into
the Mid-Atlantic, suppressing any shower and thunderstorm
activity further south. However, considering it is mid-July
after all and the airmass really doesn`t change all that much in
wake of the dying front, occasional rounds of convective
showers and storms are possible each afternoon with potentially
another frontal boundary approaching on Friday. Temperatures are
expected to be slightly above normal with highs in the upper
80s to low 90s daily, where heat indicies may reach close to or
top 100 in some spots.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Tonight... VFR until after 06Z. Similar to last night, expect
low clouds and fog to advect into the region. It seems more
favorable for a low stratus event (as compared to fog).
Regardless, expect conditions to decrease to IFR conditions.
There is a small chance (30%) that the lower conditions won`t
reach as far west as KRDG and KABE. winds are likely to be light
across the area. Direction should favor a E or SE direction,
but may be variable at times.

Saturday...Any lingering low clouds or fog should slowly erode
by 18Z. VFR conditions are expected. More TSRA is possible after
18Z. Highest risk for TSRA tomorrow will be at KABE and KRDG.
Winds light (5kt or less) favoring a SE direction.

Outlook...

Saturday night through Wednesday...Overall, VFR conditions.
However, afternoon and evening SHRA/TSRA may result in brief
periods of sub- VFR conditions daily. Sub-VFR conditions are
also possible overnight due to low clouds and fog, but
uncertainty remains on this potential, so confidence is low.

&&

.MARINE...
Winds and seas should stay below Small Craft Advisory criteria
through Saturday.

Outlook...

Saturday night through Wednesday...No marine headlines expected.
Winds generally remain less than 15 kt with seas around 2-3 feet.
Showers and thunderstorms are possible daily, primarily in the
afternoon and evening hours.

Rip Currents...

On Saturday, there will be an increasing easterly flow first at
5 to 10 mph, increasing to 10 to 15 mph in the afternoon.
Breaking waves will be as high as 2 to 3 feet. This will result
in a MODERATE risk for the development of dangerous and life
threatening rip currents at the Jersey Shore, and a LOW risk
for the development of dangerous rip currents at Delaware
Beaches.

On Sunday, winds will be out of the southeast at around 10 mph
with breaking waves around 2 feet. This results in a LOW risk
for the development of dangerous and life threatening rip
currents at the Jersey Shore and at Delaware Beaches.

Rip currents occur often in the vicinities of jetties and piers
and the speed of the currents are generally maximized at low
tides.

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

&&

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

&&

$$

SYNOPSIS...DeSilva/RCM
NEAR TERM...Johnson/OHara
SHORT TERM...DeSilva
LONG TERM...DeSilva
AVIATION...DeSilva/Johnson/OHara
MARINE...DeSilva/Johnson/MPS