374
FXUS61 KPHI 040530
AFDPHI

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

.SYNOPSIS...
High pressure will be in place across the Mid Atlantic region
through today, before weakening tonight into Tuesday as high
pressure builds across northern New England and southeast Canada
for much of the upcoming week. The high will shift offshore of
the Canadian Maritimes Friday as a possible low pressure system
or surface trough possibly lifts northward along the eastern
seaboard.

&&

.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 TUESDAY NIGHT/...
Tranquil weather will continue Tuesday and Tuesday night as
high pressure weakens across the Mid Atlantic, but builds well
to our north across northern New England and southeast Canada.
Even with an onshore flow, temperatures on Tuesday are forecast
to be well above normal with highs near 90 for some areas. A
precipitation- free forecast will continue through Tuesday
night, although cloud cover will likely be on the increase with
onshore flow.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
With high pressure located well to our north for much of the
upcoming week, cloud cover will likely continue through much of
the period. With an increase in moisture across the area, there
will be a slight chance of showers for portions of the area,
mainly for the southern and western portions of the forecast
area. With the onshore flow, possible cloud cover, and lowering
thicknesses, temperatures are expected to low back near normal
for much of the period.

The big questions mark for the long term is the possibility of
an area of low pressure to develop offshore of the southeast
coast and possible northern direction it could take. Due to the
varying models solutions, we do not plan to stray from the NBM
forecast.

&&

.AVIATION /05Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Thru 12Z this morning...VFR. Winds NE 5 kts or less. Periods of
calm likely. High confidence.

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-Wednesday...VFR conditions expected.

Wednesday night-Friday...Generally VFR. A slight chance of a
shower. Possible near MVFR clouds late at night/early morning.

&&

.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-Tuesday night...Sub Small Craft Advisory conditions
expected.

Wednesday-Friday...Small Craft Advisory conditions possible with
seas 5+ feet.

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...RCM/Robertson
NEAR TERM...RCM
SHORT TERM...Robertson
LONG TERM...Robertson
AVIATION...Cooper/RCM/Robertson
MARINE...AKL/RCM/Robertson