327
FXUS61 KPHI 122325
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
725 PM EDT Sat Jul 12 2025

.SYNOPSIS...
A cold front approaches the region Sunday into Monday before
slowly crossing through later Monday into Tuesday. Thereafter,
the front stalls near/over the region before it is lifted back
as a warm front later Wednesday into Thursday. Another cold
front approaches towards the end of week.

&&

.NEAR TERM /THROUGH SUNDAY/...
Another round of diurnally driven convection is possible into
the early evening. The best low level convergence and synoptic
scale lift is west of our region over central PA, MD and VA. So
the highest chances for our region will be west of the fall
line. Storm motions, like yesterday, are expected to be very
slow, resulting in a marginal (1 out of 4) risk for localized
flash flooding.

Tonight will be similar conditions to the last two nights, with
continued onshore flow, resulting in another round of low
clouds. Fog will be possible at the coast, but for the most part
this looks like more of a low cloud set up than a fog set up.

As the main trough inches closer to our area on Sunday, chances
for showers and thunderstorms will increase slightly. For the
most part, though the day, it appears as if convection will stay
west of our region.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
A cold front approaches our region from the west Sunday night
into Monday while slowing down and undergoing frontolysis. Very
slowly, this front makes its way through the region
Monday into Tuesday before eventually stalling over/near the
region for the remainder of the term.

Given this situation, expect the showery summertime pattern to
continue. Showers and thunderstorms expected for the Sunday
night period with the front approaching, especially for the
western half of the CWA. Some spotty showers could linger for
areas during the Monday morning time frame, depending on the
time frame of frontal movement. Another round of showers and
thunderstorms expected for the region Monday afternoon into the
nighttime period as the front only sags ever so sightly to the
southeast with time. While there is mainly only a slight chance
of PoPs for Tuesday, some spotty showers and thunderstorms
should not be ruled out for the afternoon time frame onwards
given the location/proximity of the stalled front.

Fog formation is possible for areas during the late nighttime
and early morning periods, but this will be dependent on
precipitation occurrence and mixing.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Stationary boundary looks to plague the region before an
approaching low pressure systems lifts it through as a weak warm
front Wednesday/Thursday. Thereafter, another cold front
approaches, looking to pass through sometime near/during the
weekend (e.g, late Friday/early Saturday).

Unfortunately, this synoptic situation supports a continuation
of the showery summertime pattern. Chances for showers and
thunderstorms Wednesday/Thursday/Friday, mainly during the
afternoon and evening time frames with diurnal heating in place.
End of the week/weekend cold front will be watched for exact
time frame of approach/passage, and its severe weather
potential.

Heat headlines may be needed for areas
Wednesday/Thursday/Friday. Guidance supports heat indices
approaching criteria.

&&

.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight...VFR conditions to start at all terminals but KACY,
which already has MVFR ceilings. A few isolated storms have
developed near KPHL and KRDG, but convective activity is
expected to wane with sunset. Low clouds are expected to develop
generally centered within a few hours of 06Z. The set up looks
more favorable for low clouds than fog, except near the coast,
including KACY, where both the lowest ceilings and lowest
visibilities are likely to occur. By 09Z, expect most locations
to have IFR conditions. Winds remain light (5 kt or less),
generally favoring the southeasterly direction, but could be
variable at times. High confidence in overall pattern, low
confidence in timing/placement of development of fog and
visibility restrictions.

Sunday...Once low clouds and fog dissipate, which should be by
15Z for most locations, but may linger through 18Z for KACY,
will see a return to VFR conditions. Storms will begin to
approach the area from the northwest by 00Z. Moderate
confidence.

Outlook...

Sunday night through Thursday...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 Sunday.

Outlook...

Sunday night through Thursday...No marine headlines expected.
Winds generally remain 15 kt or less with seas around 2-4 feet.
Showers and thunderstorms are possible daily, primarily in the
afternoon and evening hours, with the greatest probability of
showers and storms being on Monday.

Rip Currents...

Today, 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 along with a medium
period southeast swell 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 1 to 2 feet. This combined with a
lower southeast swell and lower wave heights 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...Wunderlin
NEAR TERM...Johnson
SHORT TERM...Wunderlin
LONG TERM...Wunderlin
AVIATION...Cooper/DeSilva/Johnson/Staarmann/Wunderlin
MARINE...DeSilva/Johnson/Staarmann/Wunderlin