569
FXUS61 KPHI 091006
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
606 AM EDT Mon Jun 9 2025

.SYNOPSIS...
A weak area of low pressure will move off the coast heading into
the day Monday. A cold front approaches from the west Monday
night and moves across the area Tuesday into Tuesday evening.
High pressure then builds in for the mid to late week period. A
cold front then looks to move southward into the region next
weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of early this morning, a weak area of low pressure is
situated just to our south near the mouth of the
Chesapeake. There are some scattered showers and a couple
storms in association with this system that are moving across
the area. Also, winds over our area to the north of the system
remain out of the east and this has helped bring in low clouds
as well as areas of mist, drizzle, and fog.

As we head into the day today, the weak system moves off the
coast while fizzling out. This should bring any showers to an
end by around mid morning for the most part. However high
pressure will remain over Atlantic Canada with ridging extending
back towards New England and this pattern will help keep E/NE
winds locked in along with the associated marine stratus. There
may also continue to be some areas of mist and patchy drizzle
around through the morning. Expect highs ranging from the upper
60s to low 70s north to the mid 70s over SE PA into adjacent
areas of southern NJ while our Delmarva zones see highs reach
the upper 70s to low 80s.

Little change is expected through this evening however by the
overnight period a cold front will be approaching from the west
and this will start to bring in another round of showers with
embedded storms. These should affect mainly our eastern PA zones
into NW NJ overnight. Since it will be at night and instability
will be limited, we are not expecting any severe weather.
However PWAT values will be fairly high (generally around 1.5 to
1.75 inches) so there could be some heavy downpours with
localized flooding...mainly for urban, low lying, and poor
drainage areas. Expect lows by Tuesday morning mostly in the low
to mid 60s.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
A cold front slowly moves across the area through Tuesday and
there may even be an area of low pressure that develops along it
that could help slow it down. The showers/storms from Monday
night may tend to diminish for a time Tuesday morning due to it
being near the diurnal minimum as far as instability. However
chances for showers/storms then increase again heading into the
afternoon with the highest POPs being for areas that will be
along and ahead of the cold front by this time. This includes
areas mainly east and southeast of the urban corridor across
portions of central and southern NJ into Delmarva. Instability
looks to be limited with ML CAPE values mostly a few hundred
j/kg or less. However the deep layer shear looks to be quite
strong so we can`t rule out some isolated strong to severe
storms. Expect highs Tuesday mostly in the middle to upper 70s
with it also being fairly humid until drier air starts to move
in late day behind the cold front.

For Tuesday night, the cold front pushes offshore through the
evening while tending to "wash out". This will bring any
lingering showers/storms quickly to and end followed by clearing
skies. Lows by Wednesday morning look to be mainly in the upper
50s to low 60s.

High pressure builds in over the east coast for Wednesday
bringing warm but dry weather with lower humidity compared to
Tuesday. Highs look to be mostly in the low to mid 80s under a
mainly sunny sky. This will be followed by clear and tranquil
weather Wednesday night with lows mostly in the low to mid 60s.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Thursday turns very warm to hot as the flow will be out of the
W/SW. Expect highs mostly in the upper 80s to around 90 except a
bit cooler near the coast and over the southern Poconos. The day
should generally be mostly sunny and free of any precip however
we can`t rule out some afternoon/evening showers/storms over the
southern Poconos as the next cold front starts to approach from
the north.

As we get into the Friday through Sunday period, it looks to
turn more unsettled once again as a cold front moves southward
into the area and may tend to slow down or even stall. Friday
should be a little cooler in our northern zones over NE PA into
NW NJ since the cold front will be already into these areas with
another very warm to hot day to the south with highs generally
well into the 80s to near 90 once again. The morning should be
dry with chances for isolated to scattered afternoon/evening
showers/storms - POPs generally around 20 to 30 percent. Heading
into the weekend, there will be a cooling trend as the cold
front pushes farther south through the area. At this time
Saturday looks to be feature the best chances for showers/storms
(POPs around 40 to 50 percent). Sunday is more uncertain and it
will depend on if the front is able to push south of the area
with high pressure building in behind it. If this occurs, it
could end up being a mainly dry day whereas if the front stalls
this could result in unsettled weather persisting through the
weekend. Stayed with the NBM which carries POPs around 40
percent for next Sunday.

&&

.AVIATION /10Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas...

Today...IFR conditions initially, improving to MVFR at times,
particularly after 18Z. East winds around 5-10 kts. Moderate
confidence.

Tonight...Mainly MVFR conditions to start, with IFR probable
(60- 80%) by daybreak Tuesday with showers moving in. There may
also be some embedded thunderstorms with the showers.

Outlook...

Tuesday...IFR expected with 60-80% chance of showers with some
embedded storms. Conditions could improve to MVFR or VFR even
later in the day.

Tuesday Night...Lingering restrictions possible (20-30%) for the
first part of the night, but improvement to VFR expected overall.

Wednesday through Friday...VFR. No significant weather.

&&

.MARINE...
A Marine Dense Fog Advisory remains in effect until 2 PM this
afternoon from Atlantic City southward. Also, seas are hovering
near 5 feet at buoy 44091 and 44065 so we`ve issued a Small
Craft Advisory until 11 AM for our northern 3 ocean zones. Seas
diminish later this morning.

No marine headlines are anticipated for tonight.

Outlook...

Tuesday through Thursday...No marine headlines expected. Some
showers and isolated thunderstorms over the waters on Tuesday.

Rip Currents...

For Today...East-northeast winds around 10-15 mph. Breaking wave
heights of 2-4 feet with a 6-7 second period. As a result, a
MODERATE risk for the development of dangerous rip currents is
in place for all beaches.

For Tuesday...South-southwest winds around 10-15 mph. Breaking
wave heights of 1-3 feet with a 6-7 second period. A MODERATE
risk for dangerous rip currents continues for Ocean, Atlantic
and Cape May County beaches, whereas a LOW risk for rip currents
is in place for Monmouth County and Delaware Beaches due to
winds blowing offshore. We`ll also be within 2 days of the Full
Moon phase, which may cause stronger than normal rip currents
under these conditions.

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

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until 11 AM EDT this morning for
     ANZ450>452.
     Dense Fog Advisory until 2 PM EDT this afternoon for
     ANZ452>455.

&&

$$

SYNOPSIS...Fitzsimmons/Hoeflich
NEAR TERM...AKL/Fitzsimmons
SHORT TERM...Fitzsimmons/Hoeflich
LONG TERM...Fitzsimmons/Hoeflich
AVIATION...Fitzsimmons
MARINE...DeSilva/Fitzsimmons