371
FXUS61 KPHI 121039
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
639 AM EDT Sat Jul 12 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 becoming more dominant toward
the middle of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Stratus is overspreading the area early this morning. While
kept some fog in the forecast, latest guidance suggests it may
not be as dense as last night, perhaps leaning more towards
mist/drizzle. This is likely partly due to the slightly greater
easterly flow at the low levels. Regardless, it will be a warm,
humid and murky start to the day for most of the region.

Despite the continued low level east to southeast flow, the
strong July sun should be more than enough to break up the low
clouds and provide a mostly sunny afternoon for most. However,
that low level flow still will keep much of the region
reasonably stable, especially when combined with weak upper
level forcing. So, while spotty showers may develop across the
entire area at some point as they did yesterday, the best best
of anything more intense remains the far north and west,
particularly higher terrain where the marine layer will be
weaker if not negligible. Also despite the marine influence,
highs should reach the upper 80s to near 90 again, but with that
high humidity, heat indices will be 95-100 for much of the
area, cooler near the coast and in the higher terrain.

Tonight, any convection early should wane and we`ll be back to
seeing low clouds and fog/drizzle redevelop, much like what
we`re seeing early this morning. Lows near or slightly above 70
except a bit cooler in the Poconos and NW NJ.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
The environment looks to become a tad more active on Sunday as
there has been a subtle uptick in PoPs (30-70%) 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
most areas near and especially east of the I-95 urban corridor
and towards the coast should remain dry into the evening. 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, with PoPs in the 50-80% 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. Locally heavy rainfall will be possible.
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
and/or Wednesday. By mid week, it does seem that Canadian high
pressure will try to take control over the Northeast while
building into the Mid-Atlantic, suppressing any widespread 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.
Another trough and frontal boundary appear to approach later in
the week, especially by Friday. Long story short, we should see
lower coverage of convection Tuesday and Wednesday, then
increasing Thursday and especially 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 /12Z SATURDAY THROUGH WEDNESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today...Low clouds/fog/drizzle should slowly erode by 16Z. 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. Moderate confidence
overall, low confidence in details.

Tonight...VFR early becoming IFR late with another round of low
clouds/fog/drizzle likely. Winds light and still favoring a
southeast direction. Moderate confidence overall, low confidence
in details.

Outlook...

Sunday 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 tonight.

Outlook...

Sunday 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, 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...DeSilva/RCM/Staarmann
NEAR TERM...RCM
SHORT TERM...DeSilva/Staarmann
LONG TERM...DeSilva/Staarmann
AVIATION...DeSilva/RCM
MARINE...DeSilva/RCM/Staarmann