517
FXUS61 KPHI 041032
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
632 AM EDT Mon Aug 4 2025

.SYNOPSIS...
High pressure will be in place across the Mid-Atlantic region
through today, then weaken tonight into Tuesday as another high
pressure system builds to our north and northeast right into the
weekend. An area of low pressure off the Southeast coast should
drift northward later this week and through the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
High pressure over our region presently will gradually weaken
today and tonight as it merges with another high building to our
north over southern Canada. A weak shortwave aloft will begin to
approach later today and tonight, but its approach should only
result in building high and possibly some mid level clouds.
Until it approaches, mostly clear conditions presently should
continue. Winds will briefly turn southwesterly today, promoting
some warm advection along with a bit of moisture advection, so
today will feel a little more like a typical summer day... highs
well into the 80s except immediate coast and Poconos, where it
will be closer to 80 or perhaps the high 70s. Dew points should
remain in the comfortable 50s, however. Increasing high clouds
and a slight uptick in dew points tonight should hold lows a
little milder, with most areas staying in the 60s.

One caveat to all this is the nearby presence of wildfire smoke
encroaching southeastward from Canada. How much of it reaches
our region still appears uncertain, so will hold off on adding
any to the forecast at this time, but its lurking nearby, so
something to keep in mind.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Some mid level ridging builds to our north Tuesday and this
will support a strengthening surface high also to our north. It
will however build down into our area, continuing an onshore
flow regime. Given some rising of the heights across our area,
high temperatures Tuesday are forecast to be well into the 80s
for much of the area. Some places from the I-95 corridor on
north/west look to make a run at 90 degrees in the afternoon,
however dew points should only peak into the lower 60s.

As we go through Wednesday, the aforementioned surface high
strengthens to our north and northeast but still extends into
our area. Some continued moisture advection should result in an
uptick in the dew points (into the mid to perhaps upper 60s).
This additional moisture should still support and increase in
cloud cover. While some guidance hints at a few showers trying
to develop inland, the probabilities are rather low and
therefore most areas may end up remaining precipitation-free.
Given more clouds and some stronger influence of the stronger
surface high to our northeast, daytime temperatures should be a
little cooler than Tuesday.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Summary...Gradually becoming more humid, and some very small
chances of showers continue for at least parts of the area.

Synoptic Overview...Our region is forecast to be between a
ridge to the north and south and a weak trough to the southwest
through Friday, then some ridging may build over our area during
the weekend. Surface high pressure while centered to our
northeast is forecast to remain extended over our area right
into the weekend. An area of low pressure off the Southeast U.S.
coast should drift northward given weak steering flow. A
surface trough may extend from that low close to our area with
time.

For Thursday through Sunday...Surface high pressure is forecast
to be centered to our northeast, however it continues to extend
across our area. This looks to keep forcing for ascent mostly
at bay for much of this time frame. Low pressure however off the
Southeast U.S. coast is forecast to drift northward with time.
A surface trough should extend northward from this low, however
it may only extend into our southern areas with time. Some
moisture should increase northward from this feature, however
the overall forcing looks to be weak and the timing is
uncertain. Some guidance shows a deeper moisture surge arriving
Thursday with showers while others are much drier. Given the
uncertainty, did not deviate from the NBM PoPs which shows our
area at 10-20 percent (20 percent mainly across our southern
areas). Given the onshore flow and more cloudiness Thursday into
Friday, daytime temperatures are forecast to below average.
Some ridging may start to build over the weekend and therefore
daytime temperatures are forecast to be at or a little above
average. The dew points are forecast to be in the 60s through
the start of the weekend, then may increase into the low 70s for
much of the area for the second half of the weekend.

&&

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

Today...VFR. Wind NE 5 kts or less, becoming SE then SSW 5-10
kts this afternoon. Some haze aloft possible from smoke, but
confidence in reduced visibilities at the surface is low at this
time. Moderate confidence.

Tonight...VFR. Wind SSW around 5 kts, turning E again late. If
any smoke mixes down, some reduced vsby possible, but confidence
low. Moderate confidence.

Outlook...

Tuesday and Wednesday...VFR ceilings at times.

Thursday and Friday...Mostly VFR.

&&

.MARINE...
Sub-SCA conditions through tonight. Winds 10 kts or less out of
the NE this morning turning SE this afternoon. Seas 2 to 4
feet. A few waves may near 5 feet across the far offshore
southeast waters.

Outlook...

Tuesday...The conditions are anticipated to be below Small
Craft Advisory criteria.

Wednesday through Friday...Small Craft Advisory conditions
possible across our ocean zones, especially due to 5-6 foot
seas.

Rip Currents...

For today and Tuesday, east to northeast winds look to be
around 10-15 mph for all beaches. Easterly swell of 3-4 feet
around 7-8 seconds looks to result in breaking waves of around
2-3 feet at all beaches. As a result, a MODERATE risk for the
development of rip current is forecast for both the Jersey Shore
and Delaware Beaches today and Tuesday.

For specific beach forecasts, visit weather.gov/beach/phi

&&

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

&&

$$

SYNOPSIS...Gorse
NEAR TERM...RCM
SHORT TERM...Gorse
LONG TERM...Gorse
AVIATION...Gorse/RCM
MARINE...AKL/Gorse/RCM