Upper Providence, Pennsylvania Weather Forecast Discussion

488
FXUS61 KPHI 242033
AFDPHI
Area Forecast Discussion
National Weather Service Mount Holly NJ
433 PM EDT Wed Sep 24 2025
.SYNOPSIS...
A stationary front is located over the area today. The front
will lift back north as a warm front tonight before a cold front
passes through late Thursday and Thursday night. Broad high
pressure will then approach from the west on Sunday into early
next week.
&&
.NEAR TERM /THROUGH THURSDAY NIGHT/...
A warm and muggy day is currently ongoing as a stationary front
currently lies across the northern third of the area. Scattered
showers on the southern side of this feature are overspreading
portions of the Delmarva, SE Pennsylvania and southern New Jersey.
With time, these showers should gradually spread northward into
northern areas as well. Overall, these showers will be light in
nature though much of the evening hours. After midnight, a more
concentrated area of development of showers with embedded
thunderstorms is expected overnight. This area will mainly be
focused over eastern Pennsylvania and northern New Jersey as the
stationary boundary lifts back north as a warm front ahead of
the main surface low located over the Ohio Valley and its
associated cold front. Some patchy fog is possible as well,
especially in areas near the warm front. Lows will be quite
mild, mainly in the mid 60s to low 70s.
For Thursday, the area will be settled well within the warm sector
so another day of the seasonably warm and humid airmass is in store.
Morning rain is likely to continue especially over eastern PA and
northern NJ, with more in the way of showers expected elsewhere
through mid-day. As a result, highs are only expected to top out in
the mid to upper 70s to low 80s, as upstream thunderstorm complexes
will cast clouds over the area for much of the day. Perhaps some
clearing is possible, especially over southern Delaware in the
afternoon, where temperatures may top into the mid 80s.
Come Thursday afternoon and evening, attention will focused on a pre-
frontal trough advancing from the west out ahead of the main cold
front. While there is expected to be a brief lull in activity mid-
day, another round of showers and thunderstorms are expected to
develop mid-late afternoon and continue into the evening hours.
Forecast soundings suggest up to 1500 J/kg of MLCAPE is possible
with 0-6 km bulk shear values up to 40-45 kts. While this type of
environment is more than enough to observe severe weather when skies
are clear; the substantial cloud cover expected much of the day may
hinder/limit this potential. However, if skies do clear more than
anticipated, there is a higher ceiling to the severe weather threat.
The Storm Prediction Center has maintained a MARGINAL risk for
severe weather across our entire area with the main threat being
damaging wind gusts. There is also a conditional tornado risk, with
a low CAPE/moderate shear environment as hodographs are curved in
the low-levels despite the lack of deep instability. Rainfall totals
through Thursday night will average between 1-2 inches with locally
higher amounts possible. Shower and storm coverage should dwindle
overnight Thursday as the cold front sweeps across the area from
west to east by Friday morning.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
High pressure will be building in from the west behind a passing
cold front on Friday. There may be some lingering showers along the
coastal locations however for most of the forecast area, it should
be a dry day. Afternoon highs will remain seasonably warm in the
lower 80s heading into the weekend.
For the weekend, a weak surface trough will be located just to the
south offshore. This will lead to the potential for some lightly
scattered showers across DelMarVa and southern NJ but heavy rainfall
is not currently anticipated.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Heading into the workweek, a broad upper ridge will be located over
the central US with at least one low pressure system well offshore.
NHC is monitoring two potential invests for tropical cyclone
development. Given the temporal range of the forecasts, we dont
currently know much what the impacts or details of the tracks
will be. NHC`s key messages verbatim say "the close proximity of
these systems could lead to interaction between them, and the
details of their long-range track and intensity forecasts... are
more uncertain than usual". Given the significant uncertainty,
the forecast will keep with a persistence forecast with modest
20-40% chances of rain for Monday-Wednesday and a general
lowering of temperatures trend through the middle of the week.
We`ll continue to monitor the systems for any potential impacts
and adjust the forecasts as confidence increases in at least
some viable solution.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas...
Rest of Today...VFR with BKN/OVC skies and scattered showers.
Southerly winds around 3-8 kt. High confidence.
Tonight...VFR early, but conditions will gradually lower to a mix of
MVFR and IFR, especially after midnight. Greatest potential of lower
restrictions at KRDG/KABE. Scattered showers with embedded
thunderstorms overnight, however confidence in any given TAF site to
have thunder is low so left out of TAF for now. South-southeast
winds around 5 kt or less. Patchy fog possible. Moderate confidence.
Thursday...IFR/MVFR conditions in the morning, should gradually
improve to VFR likely after 18Z. Periods of rain and showers
expected throughout the morning with a lull mid-day. A second round
of showers and storms expected in the afternoon from west to east
which will cause another period of sub-VFR conditions. Southerly
winds around 7-12 kt with locally higher gusty winds possible.
Moderate confidence.
Outlook...
Thursday night...Sub-VFR conditions are likely to continue with
showers and thunderstorms gradually tapering off overnight.
Southwest winds around 5 kt. Moderate confidence.
Friday through Sunday...Sub-VFR conditions likely, especially early
Friday, before improving by the weekend. A chance of showers will
continue through Sunday.
&&
.MARINE...
No marine headlines are in effect through Thursday. South winds
around 10-15 kt through tonight with seas of 3-4 feet. On Thursday,
south winds increase to around 15-20 kt with seas of 3-4 feet. A few
sporadic gusts up to 25 kt possible, but confidence is not high
enough to warrant SCA`s at this time. Scattered showers and
thunderstorms expected through Thursday.
Outlook...
Thursday night through Sunday...No marine headlines currently
expected. A change (30-40%) of showers with a small chance
(10-20%) embedded thunderstorms possible each day.
Rip Currents...
For Thursday...Decided that MODERATE for both NJ/DE waters looked
good for Thursday. The overall swell is still onshore, but decreasing.
Waver periods of around 10 seconds are less than on Wednesday.
Winds will increase notably during the afternoon, which could
locally enhance conditions, but confidence for any higher
category is low (but not zero).
For Friday...chose the MODERATE risk for NJ waters and LOW for
Delaware waters with the Wed evening update. The wind pattern
behind the departing low looks to bring winds mostly offshore
and rather light for much of of the day. Swell continue to lower
as offshore storms move further away from our waters.
For specific beach forecasts, visit weather.gov/beach/phi
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...High Risk for Rip Currents until 8 PM EDT this evening for NJZ014-
     024>026.
DE...High Risk for Rip Currents until 8 PM EDT this evening for DEZ004.
MD...None.
MARINE...None.
&&
$$
SYNOPSIS...MJL
NEAR TERM...DeSilva
SHORT TERM...Deal/MJL
LONG TERM...Deal/MJL
AVIATION...Deal/DeSilva/MJL
MARINE...Deal/DeSilva/MJL/po

NWS PHI Office Area Forecast Discussion