408
FXUS61 KPHI 102102
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
502 PM EDT Thu Sep 10 2026

.WHAT HAS CHANGED...
Aviation section updated for 18Z TAFs.

&&

.KEY MESSAGES...
1. A cold front will cross through the area into tonight,
bringing the potential for a round of showers and thunderstorms.


2. Another disturbance will approach the area Saturday into
Sunday and produce a round of showers and thunderstorms.

&&

.DISCUSSION...
KEY MESSAGE 1...A cold front will cross through the area into
tonight, bringing the potential for a round of showers and
thunderstorms.

Mostly sunny, warm and humid today with surface dewpoints
rising into the upper 60s and low 70s. Highs will top off in the
mid to upper 80s. As a result, max heat index values will be
around 90 degrees, perhaps in the low 90s in Delmarva and
extreme southern New Jersey.

Another cold front approaches into tonight. Highest instability
will be across Delmarva and southern New Jersey where SBCAPE
values will be as high as 500 to 750 J/kg, and MUCAPE values
will be slightly higher. PWATs will be 1.5 to 1.75 inches in
Delmarva where locally heavy rain is possible. In these areas
will be the highest chances for convection, mainly after
midnight through around daybreak Friday.

Following any morning showers, Friday will shape up to be a nice
day with clouds breaking later in the day and humidity falling
into the afternoon. Highs in the upper 70s to low 80s in most
areas.


KEY MESSAGE 2...Another disturbance will approach the area
Saturday into Sunday and produce a round of showers and
thunderstorms.

In the wake of Thursday`s cold frontal passage, high pressure
will briefly build into the region for Friday. Dry conditions
are expected with temperatures generally in the 70s to near 80.
However, guidance continues to indicate that the front will
stall somewhere over the Carolinas before lifting slowly back
north towards the area for the weekend. A mid-level shortwave
looks to pass through the area Saturday night and an area of
surface low pressure is likely to ride along the boundary as it
shifts slowly northward into the area.

Confidence is increasing in scattered shower and storm activity
across the region Saturday through Saturday night. As of right
now, instability looks to be meager, limiting any severe storm
threat. However, forecast soundings across the area indicate
deeply saturated vertical profiles, especially across the
southern half or so of the area. PWATs look to exceed 2 inches.
Given this, any storms across the area could be efficient
rainfall producers. As such, there does appear to be some
potential for isolated instances of flash flooding. The WPC has
highlighted the entire area with a Marginal Risk (1 of 4) in
their latest Excessive Rainfall Outlook to account for this
potential.

Some time late Saturday night or Sunday, the front and low
pressure will track offshore, bringing an end to the shower and
storm chances and a return of tranquil conditions to start the
next work week. With that said, timing discrepancies limit
confidence on Sunday, as a slower progressing system could lead
to rain chances lingering at least into Sunday afternoon.

In terms of temperatures, they look to hold fairly steady in
the mid 70s to mid 80s through the weekend and into early next
week, with perhaps a slow warming trend.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Through 00Z...VFR. West to northwest winds around 10 kts with
gusts up to 20 kts. High confidence.

Tonight...Mostly VFR, though sub-VFR visibility possible at
KMIV/ACY. Potential for SHRA/TSRA as well. Winds shifting north
to northeast around 5-10 kts. High confidence in prevailing VFR,
lower confidence on any restrictions at MIV/ACY.

Outlook...

Friday through Friday night...VFR. No significant weather.

Saturday through Sunday...Periods of sub-VFR conditions will be
possible with scattered showers and storms.

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

&&

.MARINE...
Small Craft Advisories were allowed to expire. West to
southwest winds will be near 10 kts.

Tonight, west winds 5 to 10 kt will turn north to northeast
late. Showers and a rumble of thunder possible overnight through
around dawn on Friday.

Outlook...

Friday through Monday...No prevailing marine hazards
anticipated with winds below 25 kt and seas below 5 feet.
Scattered showers and storms will be possible Saturday and into
parts of Sunday.

Rip Currents...

On Friday, winds turn more northerly and will be around 5 to 10
mph. Breaking waves decrease to 2 feet or less. Dominant swell
will be around 1-2 feet with a period of 6 to 8 seconds from the
southeast. With more tranquil conditions expected to close out
the week, there will be a LOW risk for rip currents at all
beaches.

On Saturday, winds turn more onshore, from the ESE to SE, around
10-15 mph. Breaking waves remain around 1-2 feet. The dominant
swell will be around 1 foot with a period of 9 seconds from the
southeast. Given the more robust onshore flow, there will be a
MODERATE risk for rip currents at New Jersey beaches and a LOW
risk for rip currents at Delaware beaches.

&&

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

&&

$$

DISCUSSION...Cooper/MPS/Staarmann
AVIATION...Cooper/MPS/Staarmann
MARINE...Cooper/MJL/MPS/Staarmann