Chester, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

213
FXUS61 KPHI 262336
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
736 PM EDT Sat Jul 26 2025

.SYNOPSIS...
A front remains situated off to our south and west with high
pressure over New England today. This front will lift back north as
a warm front on Sunday, ahead of a weak cold front that will pass
through Sunday night. High pressure returns for Monday and Tuesday,
before another cold front passes through Wednesday into Thursday.
High pressure returns for Friday into next weekend.

&&

.NEAR TERM /THROUGH SUNDAY/...
730 PM update...
Given fairly widespread reductions in visibility across NJ into
parts of eastern PA, have added smoke to the forecast (we can
actually smell it at the office). This smoke is from Canadian
wildfires. It should dissipate/move away overnight as showers
arrive and winds turn more southerly. No other changes at this
time.

3 PM discussion...
For tonight, low pressure across Southern Canada will move east. Its
attached fronts will also move east and bring more clouds and
increasing chances for showers/tstms tonight. The first batch of
tstms/rains already across western/central PA and will move
into our western counties shortly. The chances for rains
decrease for the S/E as some of the activity will diminish as it
moves thru. Heavy rains and perhaps some gusty winds are
possible for Delmarva and SE PA areas into the evening. Pops
range from chance/slight chance for SE most areas to Likely for
the southern Poconos and Berks county. Lows tonight will only
drop into the low/mid 70s most spots with maybe some upper 60s
for north NJ and the southern Poconos.

Tomorrow will certainly not be the ideal weekend day with low
pressure passing well  to the north and the warm/cold front combo
expected to move through. Plenty of clouds expected and occasional
showers and tstms thru the day. Likely and categorical pops will
continue in the fcst. Heavy rains are possible with the high PWAT
air across the Ohio Valley being imported into the area. There is a
Marginal risk for Severe tstms too with gusty winds with primary
threat. The clouds and rains will keep temps from going above normal
with mid/upper 80s S/E and low 80s N/W expected for highs on
Sunday.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
Convection from Sunday afternoon will begin to wane into Sunday
evening with the loss of diurnal heating. The weak surface cold
front will move through from north to south, pushing off the coast
by Monday morning. Skies will clear out behind the front with lows
falling into the upper 60s to mid 70s.

Monday and Tuesday will feature dry conditions with mostly sunny
skies both days as broad high pressure builds into the region from
the south. Perhaps a spotty shower or storm is possible on Tuesday,
but not expecting anything of significance. Behind the front, there
won`t be much of a push of cooler or drier air though, as
temperatures and dew points are expected to gradually increase
through the period. Highs on Monday will mainly be in the upper 80s
to low 90s with highs on Tuesday in the low to mid 90s. Dew points
will also be in the 70s both days, so it`ll feel quite uncomfortable
outside once again. This will result in heat indicies around the
region in the 95-102 degree range on Monday and 100-105+ degree
range on Tuesday. Likely will need at least some sort of heat
headlines for Monday and Tuesday in the coming days.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Little changes have been made to the long term period as Wednesday
will still feature one more hot & humid day with thunderstorm
potential, before a much more refreshing airmass moves in for the
end of the week into next weekend.

Greatest attention to the long term period will be on Wednesday as a
strong cold front will approach the area, crossing through the area
either Wednesday night or Thursday morning. This should bring a more
widespread opportunity for thunderstorms to the area -- some of
which may be strong to severe as indicated by some of the machine
learning guidance in the mid-range. However, the biggest issue is
that most of the guidance continues to delay the arrival of the
front, meaning that any convection may not move into the area until
late afternoon or even as late as the evening hours. If this were
this case, this would diminish chances for severe weather. This will
continued to be monitored over the coming days. Otherwise,
Wednesday will feature heat indicies in excess of 100 degrees.

By Thursday, the depending on the timing and forward progression of
the cold front, there will likely be some lingering shower and
thunderstorm activity around through Thursday night. For Friday and
into next weekend, we should see some drastic improvements across
the area as the cold front moves away and strong high pressure
builds over the Great Lakes. This will result in dry conditions
where our temperatures are expected to be as much as 5-10 degrees
below average through next weekend.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight... Areas of smoke have thrown a small wrench into the
forecasts across NJ and far eastern PA including PHL, with visby
reductions down to 4 miles. Will maintain that this evening as
it likely persists until a stronger southerly flow takes hold
and/or rain showers mix out some of it. Otherwise, still expect
lowering CIGS then VSBYs from West to east as showers and a few
tstms arrive with the approaching front. Lower conditions
earlier N/W then mostly after midnight S/E. Conditions overall
will decrease to MVFR, but a few short periods of IFR with any
tstm. East to Southeast winds 5 to 10 knots. Medium confid
overall.

Sunday... Low clouds and lower vsbys in showers and fog look to
prevail across the region much of Sunday. We`ll go along with
the guidance which suggests that high-end IFR or low-end MVFR
conditions will be across the region. Low confid in when/if
improvements will take place, but for now have mostly placed
VCTS during 18-21Z period most terminals. South winds mostly
around 10 knots. Low Confid.

Outlook...

Sunday night...Sub-VFR conditions possible with a chance of showers
and thunderstorms.

Monday through Wednesday...VFR. No significant weather expected.

Wednesday night through Thursday...Sub-VFR conditions possible with
a chance of showers and thunderstorms.

&&

.MARINE...
The East to Southeast onshore flow looks to continue into the
evening and then weaken overnight. Winds will become mostly South on
Sunday, Winds and seas will remain  below SCA levels thru the
period. There will be showers and a few tstms across the waters
tonight and Sunday. Higher winds and seas near tstms are expected.

Outlook...

Sunday night through Thursday...No marine headlines expected as
winds will largely remain below 20 kt and seas around 2 feet or
less. A chance of showers and thunderstorms expected on Sunday night
with fair weather expected for Monday through Wednesday. Another
chance of showers and storms are possible for Wednesday night into
Thursday.

Rip Currents...

For Sunday, winds be southerly around 5 to 10 MPH. Breakers of
around 1 to 2 feet are expected. Period will be 5 to 8 seconds.
As a result, a LOW risk for rip currents is in place at all
beaches.

For Monday, winds turn northerly and then easterly around 5 to
10 MPH. Breakers decrease slightly to around 1 foot. Period
will remain 5 to 8 seconds. As a result, a LOW risk for rip
currents is in place at all beaches.

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

&&

.TIDES/COASTAL FLOODING...
Due to the new moon occuring on July 24, some spotty minor coastal
flooding may occur again with the high tide tonight into Sunday.
The most likely locations for any spotty minor tidal flooding
are along the Delaware Bay, as well as around Cape May. No coastal
flooding is anticipated along the northeastern portion of Chesapeake
Bay.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...Air Quality Alert until midnight EDT tonight for NJZ001-
     007>010-012>027.
DE...None.
MD...None.
MARINE...None.

&&

$$

SYNOPSIS...AKL/DeSilva
NEAR TERM...OHara/RCM
SHORT TERM...AKL/DeSilva
LONG TERM...AKL/DeSilva
AVIATION...DeSilva/OHara/RCM
MARINE...DeSilva/OHara/RCM
TIDES/COASTAL FLOODING...PHI