500
FXUS61 KPHI 091034
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
634 AM EDT Wed Jul 9 2025

.SYNOPSIS...
A slow moving frontal boundary will waffle across the Mid-
Atlantic through late week as additional disturbances move
through. Bermuda high pressure will be in place through the
weekend, eventually breaking down for the start of the new work
week. Several disturbances will pass through over the weekend as
well.

&&

.NEAR TERM /THROUGH TONIGHT/...
A weak, diffuse frontal boundary continues to sit over the mid
Atlantic but the storms from earlier have ended. However today
will virtually be a rinse and repeat kind of day in terms of the
overall forecast, except the frontal boundary is a little
farther south, suppressing the overall threat of convection a
bit further south. Expecting partly cloudy skies in the morning
to give way to mostly cloudy skies come the afternoon. With the
tropical and deep moisture airmass persisting in addition to the
nearby frontal boundary, yet another round of showers and
thunderstorms will develop around late afternoon today.
Greatest threat will be from Philadelphia on south, where better
atmospheric parameters overlap with one another, so SPC has a
SLIGHT risk in those areas, with a MARGINAL risk remaining
elsewhere. Similarly, WPC has kept a SLIGHT risk for excessive
rainfall for most of the area on Wednesday as little change in
the overall atmospheric environment is expected. A new Flood
Watch for flash flooding is in effect that basically includes
all areas from the I- 78 corridor southward. Compared to
Tuesday, the timing of the convection will be a bit
later...mainly after 5 PM so we begin the Flood Watch at this
time. All in all another muggy and humid day is expected.
Temperatures will be a few degrees cooler due to more cloud
cover compared to today where heat indicies will largely remain
in the 90s for the majority of the area. So it looks like we`ll
fall short of needing any heat headlines.

Showers and storms continue this evening with the severe threat
gradually diminishing with time but the flash flood threat
persisting at least through the evening period. PWATs will
remain around 2 inches meaning heavy downpours will be capable
of producing locally 2-3 inches of rain within a 1 to 3 hour
timeframe. Showers/storms are likely to linger overnight near
and south of the urban corridor however the intensity of them
and associated rainfall rates should diminish. The Flood Watch
runs until 2 AM. Lows by Thursday morning should be mainly in
the upper 60s to low 70s.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
A warm and humid airmass will be over the Northeast and Mid-
Atlantic for the Short Term period. Surface dew points will be in
the low to mid 70s, along with highs generally in the mid 80s. This
will yield heat index values in the low to mid 90s. These high dew
points will also keep low temperatures at night quite warm, and lows
will generally be in the lower 70s.

Unsettled weather will remain on tap as a frontal boundary will
hover over the area. Abundant low level moisture will be in place
given those high dew points, and PWATs will be up to and in excess
of 2 inches.

Another round of showers and thunderstorms will impact the area
Thursday afternoon and evening as shortwave energy approaches from
the west and passes through the region. Given how warm and humid
conditions will be, locally heavy rain and damaging wind gusts are
possible once again. This pattern will repeat yet again on Friday.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A fairly typical summertime pattern is on tap for the Long Term
period with warm and very humid conditions. Surface dew points will
generally be in the low to mid 70s though it is possible that during
the peak heating of the day dew points drop by a few degrees due to
mixing. Highs will generally be in the mid to upper 80s, possibly
around 90 in some spots. This will give way to max heat index values
generally in the low to mid 90s.

A series of disturbances will pass through the region from time to
time, but confidence in timing and placement is low. Will generally
follow the NBM and go with 30 to 50 percent PoPs for most of this
time, though the NBM is indicating 60 percent PoPs for the southern
Poconos, Lehigh Valley, and Berks county on Sunday due to a stronger
system possibly approaching then. Important to note that any showers
and thunderstorms will mostly be in the afternoon and evening hours
and there are not many factors indicating precipitation would be
widespread and organized at this time.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today...Low stratus along with some mist and fog will cause
there to continue to be some fluctuations back and forth to sub
VFR through around mid morning. Otherwise, becoming VFR by the
latter part of the morning through much of the afternoon before another
round of showers and thunderstorms develops by late afternoon.
Any showers and storms may cause localized areas of VSBY/CIG
restrictions. Southwest winds around 5-10 kt. Moderate
confidence.

Tonight...Showers and storms continuing with associated
restrictions to at least MVFR or lower at at times. Winds light
and variable (around 5 knots or less) but generally favoring a
S to SW direction.

Outlook...

Thursday through Sunday...Overall, VFR conditions. However,
afternoon and evening SHRA/TSRA may result in brief sub-VFR
conditions if a given storm passes over a terminal. Sub- VFR
conditions possible at night due to fog and low clouds, but
confidence low on timing and placement.

&&

.MARINE...
No marine headlines are in effect through today and tonight.
Some showers are lingering early this morning over our southern
waters with another round of showers/storms expected late
day today into tonight. These could once again bring localized
wind gusts in excess of 34 kt.


Outlook...

Thursday through Sunday...Sub-SCA conditions for this period.
Afternoon and evening showers and thunderstorms possible each
day. VSBY restrictions possible from time to time, especially at
night.

Rip Currents...

For Wednesday, a south/southwest shore parallel wind of around
10-20 MPH and breaking waves of around 2-3 feet will result in
a MODERATE risk for the Jersey Shore. With wind direction mainly
offshore along the Delaware Beaches, a LOW Risk for rip
currents is in place. Similar conditions are expected for
Thursday so we`ll continue with a MODERATE risk for the Jersey
shore and a LOW risk of rip currents for the 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

&&

.HYDROLOGY...
A Flood Watch was issued for areas along and south of I-78 for
Wednesday. Rainfall of around 0.5 inches to upwards of 3 to 4
inches fell across the watch area. This results in a saturated
surface and low FFG values within the watch area. It will not
take much to cause further flooding issues, especially in SE PA,
where widespread flooding was reported today. Rainfall rates of
2 to 3 inches per hour are possible with thunderstorms rolling
through Wednesday Evening.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Flood Watch from 5 PM EDT this afternoon through late tonight
     for PAZ060>062-070-071-101>106.
NJ...Flood Watch from 5 PM EDT this afternoon through late tonight
     for NJZ009-010-012>027.
DE...Flood Watch from 5 PM EDT this afternoon through late tonight
     for DEZ001>004.
MD...Flood Watch from 5 PM EDT this afternoon through late tonight
     for MDZ012-015-019-020.
MARINE...None.

&&

$$

SYNOPSIS...Fitzsimmons/MPS
NEAR TERM...DeSilva/Fitzsimmons/Hoeflich/Staarmann
SHORT TERM...Fitzsimmons/MPS
LONG TERM...Fitzsimmons/MPS
AVIATION...DeSilva/Fitzsimmons/MPS
MARINE...DeSilva/Fitzsimmons/MPS
HYDROLOGY...