059 
FXUS61 KPHI 282022
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
422 PM EDT Sun Sep 28 2025

.SYNOPSIS...
High pressure will maintain its influence over the area into 
the new work week. A strong cold front will pass through the 
area around mid-week, followed by a strong high pressure system 
building southward in its wake through the remainder of the 
week.

&&

.NEAR TERM /THROUGH MONDAY/...
We continue to see a clear sky with some sunshine for the 
remainder of the day as a high pressure system is building in 
from the north and west. This does start to change a bit as we 
head through the evening and into tonight. Clouds for our 
coastal areas and southeastern zones do start to filter back in.
Overnight, clouds look to be mainly confined south and east of 
the I-95 corridor. It will be a clear sky as you head west and 
mostly to partly cloudy as you head southeast. Due to a pretty 
clear sky overall across the area, light winds, and even some 
lingering moisture near the ground from previous rain will lead 
to some potential patchy fog. Right now, the best confidence 
looks to be Delmarva, parts of New Jersey, and parts of the 
Lehigh Valley. Lows tonight are in the mid 50s to mid 60s.

On Monday, our high pressure system remains our dominant weather 
feature. This high pressure system does retreat slightly to the 
northwest which will allow moisture to usher in from the south in 
the form of mid and high level clouds. Now there are ongoing 
tropical systems in the Atlantic to our southeast, but with high 
pressure being our main dominant weather feature, it will keep those 
systems away from our area. What we mainly see is some of this 
moisture moving into our area from the south in the form of the 
cloud cover mentioned above. There may even be a spotty to 
isolated light shower in Delmarva but that seems pretty limited 
at this time. Highs on Monday are in the mid 70s to low 80s.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
By Monday night, Humberto and TD 9 will be to our southeast and
south, respectively, sending plenty of high clouds up our way 
but otherwise, with minimal influence on our weather just yet. 
Weak high pressure will prevail as a strong cold front 
approaches from the northwest. This will result in a dry night 
with lows in the upper 50s to mid 60s.

Both tropical systems likely make their closest approach during
the day Tuesday, but they will remain quite far away. This will
keep the high clouds around, but otherwise, little change in 
our weather just yet as the approaching cold front will have yet
to cross the region. Highs near 80 overall. 

More substantial changes begin Tuesday night as the Humberto 
exits stage right and TD 9 also starts moving eastward, while 
the strong cold front finally crosses our region. This will 
allow clouds to diminish and northerly winds to increase, with 
lows in the 40s far north and west, 50s for most, but still 60s 
in the far southeast. 

We'll feel autumn in force on Wednesday, with a gusty north to 
northeast breeze as Canadian high pressure builds in behind the 
cold front and the tropical systems continue to retreat eastward
over the open Atlantic. Thus, despite much more sun, temps will
be about 10 degrees cooler than Tuesday, closer to 70.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Canadian high pressure will continue building southward 
Wednesday night into Thursday, ending up nearly directly 
overhead by Thursday night. Thus, skies will be more clear than 
not, with a gradually diminishing breeze. Lows Wednesday night, 
with a bit of a breeze still blowing, will range from near 40 to
the mid 50s, while the light winds and clear skies expected 
Thursday night should promote some upper 30s to low 50s, perhaps
with a touch of frost in the coldest spots of the Poconos and 
NW NJ. Highs Thursday should be quite cool compared to recent 
days, with most areas only in the 60s.

High pressure remains pretty much directly overhead thru the 
weekend, with gradual moderation of the air mass. Both highs and
lows will creep up 3 or 4 degrees each day, with readings 
Sunday ending up in the mid-upper 70s for highs and the mid 50s 
to low 60s for lows. Skies should remain more clear than not.

&&

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

Rest of Today...VFR with winds N-NW around 5 kt or less. 
High confidence.

Tonight...VFR initially, but VSBY restrictions in BR possible 
(20 to 30 percent) after 06Z. Nearly calm winds. Low confidence 
on sub-VFR conditions.

Monday...VFR with winds out of the NE at 5-10 knots.

Outlook...

Monday night through Friday...VFR conditions should prevail.

&&

.MARINE...
Sub-Small Craft Advisory conditions through Monday. A south to 
southeast wind today becomes west to northwest late tonight at
5-10 kts. By Monday the wind is northeast at 5-10 knots. Seas 2
to 4 feet.


Outlook... 

Wave heights on the ocean will begin to build to Small Craft 
Advisory levels as we head through Monday night due to tropical 
systems well to our southeast. Winds will also begin to increase
as we head into Tuesday, with gusts starting to reach SCA 
levels by days end and wave heights continuing to build. The 
worst conditions, with winds gusting potentially to gale force 
and wave heights potentially exceeding 10 feet, looks likely to 
occur Tuesday night through Wednesday. These both should 
gradually ramp downward thereafter, with sub-SCA winds likely 
returning by Friday, but wave heights perhaps lingering above 5 
feet at least early Friday.

Rip Currents...

For Monday, the increasing influence of longer period swells around 
13 to 16 seconds combined with there being multiple swell groups 
along with northeast winds around 10 to 15 mph will result in a 
MODERATE risk for the development of dangerous rip currents at all 
beaches. Generally expect wave heights in the surf zone to be around 
2-3 feet. 

For Tuesday, the long period swells associated with the tropical 
systems to our south will continue to build and this will result in 
a HIGH risk for the threat of dangerous rip currents at all beaches. 
Generally expect rough surf conditions as wave heights in the surf 
zone look to be around 3 to 5 feet. 

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

&&

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

&&

$$

SYNOPSIS...Fitzsimmons/RCM
NEAR TERM...Guzzo
SHORT TERM...RCM
LONG TERM...RCM
AVIATION...Guzzo/RCM
MARINE...Fitzsimmons/Guzzo/RCM