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283
FXUS61 KPHI 062330
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
730 PM EDT Sun Jul 6 2025

.SYNOPSIS...
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Bermuda high pressure will remain in place through this week.
Chantal`s remnants will pass to our south late Monday, then a
few additional weak systems will impact the region through the
remainder of the week.
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&&

.NEAR TERM /THROUGH MONDAY/...
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Tonight...A few showers across portions our our Delmarva zones
are expected to dissipate this evening. It will become
increasingly more humid through the night and temperatures will
be seasonably warm with lows only dropping below 70 degrees
across the far N/W areas. Low clouds will move in towards
daybreak while patchy light fog could develop too. Light S to SE
winds expected.

Monday...The influence of (the remnants of) Chantal arrive with
deeper moisture along with more upper shortwaves and decent
instability. We expect increasing chances for showers and
scattered tstms as the morning progresses and into the
afternoon. Localized flooding is possible due to the increasing
precipitable water, especially for the I-95 corridor and most
of Delmarva. There may be a few high rainfall totals (over 2
inches) but the overall speed of the system should keep most
reports in the 1 to 2 inch range. These also could be a few
gusty thunderstorms.

The latest forecast has high temps on Monday a degree or two
cooler than yesterday. This along with the higher dew points
will keep heat indices/apparent temps just short of Heat
Advisory criteria.
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&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
The overall atmospheric setup for Monday night through Tuesday night
is a continuation of Monday. Coverage of showers and thunderstorms
will be isolated Monday night before coverage picks back up during
the day Tuesday. A cold front will be sinking southward Monday night
but does not actually start to fully move into the area until
Tuesday and stalls out across the southern half of the area by
Tuesday night or Wednesday morning.

During the day Tuesday, the coverage of showers and
thunderstorms increases as the cold front sinking southward
acts as an increasing trigger mechanism to an already conducive
environment for diurnally driven convection. We will be well
into a tropical air mass with temperatures reaching the mid 80s
to mid 90s and dew points will be well into the 70s. This means
heat index values will near 100 degrees for the urban corridor,
southern New Jersey, and Delmarva. A Heat Advisory might be
needed for the urban corridor if the trend continues. This
environment will support growing instability. MLCAPE values are
upwards of 2000-3000 J/kg but shear will be on the lower side.
As a result, the potential is there for isolated severe
thunderstorms with water loaded downdrafts leading to the
primary concern being damaging wind gusts. Our whole area is in
a Marginal (1/5) risk for severe weather for this exact reason.

Another concern is the localized flash flooding threat. Forecast
soundings on Tuesday show a prime heavy rain profile with tall
skinny CAPE, PWAT values of 2-2.3 inches with occasional periods of
2.5 inches, a suitable warm cloud layer depth, and the potential for
training showers and storms that will be sufficient rainfall
producers. Our whole area is in a Marginal (1/4) risk in the
Excessive Rainfall Outlook for the risk of localized flash flooding.

By Tuesday night, the coverage becomes more isolated as the
diurnally driven convection starts to diminish but the cold
front does stall over the southern portion of our area.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
We stay unsettled into the long term with the cold front staying
stalled across the area and multiple disturbances moving through. On
Wednesday, there will be isolated showers and thunderstorms around
but there is the potential for some more scattered coverage near the
stalled front located close to Delmarva and southern New Jersey as
this front might act as a focal point to enhance the daytime
convection. On Thursday and Friday, a weak disturbance looks to move
through which will lead to scattered showers and thunderstorms both
days. Another weak disturbance moves in for Saturday keeping showers
and thunderstorms going.

During the second half of the week and into the beginning of the
weekend, high temperatures will be mainly in the 80s. Dew points
will remain in the 60s and 70s, so we continue to hold onto the
humidity.

&&

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

Tonight...VFR, then MVFR ceilings developing after 06z followed
by areas of IFR ceilings. Local fog possible late. Southwest to
south winds around 5 knots, becoming light and variable. Low
confidence.

Monday...IFR ceilings lift to MVFR during the morning then to
VFR around 16z. Some showers and thunderstorms will be around,
with any thunderstorms mostly in the afternoon. Continued with
a VCSH mention and then a PROB30 regarding the afternoon
thunderstorm potential. Southerly winds increasing to near 10
knots. Low confidence.

Outlook...

Monday night through Friday...Prevailing VFR with daily chances
for thunderstorms, especially in the afternoon and evening
hours. Areas of fog possible at night.
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&&

.MARINE...
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Winds and seas will remain below SCA levels into Monday. Winds
and seas do increase Monday afternoon and come up just short of
SCA levels. We`ll hold on any headline attm. Isolated
showers/tstms into the early evening for Delaware Bay and
Delaware Coastal waters today then more scattered showers/tstms
Monday afternoon/evening. As always, higher winds and seas
locally near tstms.

Outlook...

Monday night through Friday...Wind and seas are forecast to
remain below advisory criteria. Daily chances of showers and
thunderstorms, otherwise fair weather.

Rip Currents...

For Monday, southerly winds will increase to 10-15 mph.
Breaking wave heights increase to 2-3 feet with a primary S
swell around 3 feet and a 6-8 second period. Given slightly
stronger winds and slightly higher waves with slightly higher
swell compared to Sunday, kept MODERATE at the more southerly
facing NJ beaches of Cape May, Atlantic and Ocean, and LOW for
the easterly facing beaches of Monmouth and DE.

For Tuesday, winds shift southwesterly and decrease to 5-10
mph. Breaking wave heights remain around 2-3 feet with a
primary S swell increasing to 4 feet at a 6-8 second period.
Given the higher swell, went with a MODERATE rip current risk at
all beaches.

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

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

&&

$$

SYNOPSIS...Guzzo/Staarmann
NEAR TERM...OHara
SHORT TERM...Guzzo
LONG TERM...Guzzo
AVIATION...Gorse/Guzzo/OHara/Staarmann
MARINE...Guzzo/OHara/RCM/Staarmann