Philadelphia, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

284
FXUS61 KPHI 231926
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
226 PM EST Tue Dec 23 2025

.SYNOPSIS...
A cold front will move through this evening with a weak high
pressure system following in its wake. This high pressure system
does not slide offshore until Christmas Day as another weak low
pressure system moves through. An active pattern will take shape for
the end of the week and weekend with the potential for a series of
storm systems impacting the area.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
All of the Winter Weather Advisories were allowed to expire.
Precipitation will continue to exit this afternoon and we trend
drier into tonight. A cold front moves through from the west
this evening into the early overnight hours bringing some cold
air with it as winds turn out of the northwest.

Low temperatures tonight are mainly in the mid to upper 30s (above
freezing) south of I-78, and close to 30 degrees north of there. So
any icy roads from refreezing snow melt should be confined to
untreated roads north of I-78. Winds will also increase overnight as
the cold front pushes offshore, which should help to dry things out
a bit more too. There continues to be a signal for wind gusts near
40-50 mph across the Pocono Plateau and higher elevations of
northwest New Jersey developing after midnight tonight into
Wednesday morning. This will be due to strong low level winds
developing beneath an inversion and the Bernoulli effect
accelerating winds across the ridge lines and mountain peaks, and
significant wind gusts are not expected outside of these areas. A
Wind Advisory was issued for tonight into Wednesday morning for
Carbon and Monroe counties. Wind gusts reaching near 40-50 mph
in the higher elevations of NW NJ appear more localized, so a
Wind Advisory was not issued for these areas at this time.
Elsewhere, gusts around 25-35 mph are forecast.

Behind the cold front that moves through tonight, a high pressure
system will approach from the west out of the Great Lakes region.
This high pressure system will keep tomorrow on the more
tranquil side. A majority of the day will be mostly clear before
clouds increase during the evening hours. Highs on Wednesday
will be in the 40s for most with the 30s for the Poconos. Winds
in the morning will still range from 25-35 mph for many with
upwards of 40-50 mph for the Poconos. Due to the high pressure
system building in, the winds will lessen through the day. By
Wednesday evening, gusts are 5-10 mph for most and upwards of 20
mph in the Poconos.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
High pressure will be overhead on Wednesday Night and moving
offshore ahead of a weak clipper system. Cloud cover increases as
the night goes on but any precipitation should hold off until
daybreak. Temperatures drop into the mid to upper 20s and low 30s.

For Christmas Day, a weak shortwave and associated area of low
pressure dive to our southeast. This will clip the southern half of
our region, bringing some light showers, though nothing of
significance and rain accumulations below a tenth of an inch.
Looking at around a 30-40% chance of rain for South Jersey and
Delmarva, with a 15-25% for southeastern PA, and the rest of New
Jersey. So, not a washout, but a mostly cloudy day with some showers
around. Temperatures will be in the low to mid 40s with upper 40s
over lower Delmarva.

Things dry out for Christmas night as an area of high pressure
slides by to the north. Temperatures generally will be in the 20s
with some teens north of I-80.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
An active and unsettled period is ahead for the weekend and
potentially into next week. Main period to watch will be Friday and
Friday Night as well as Sunday and Sunday Night as two systems
impact the region, likely bringing some form of wintry weather.

The first system comes in Friday into Friday Night. There is a
lot of uncertainty with this system as high pressure off the
north will result in some cold air in place, but warm air aloft
will be trying to erode that cold air. There likely will be a
transition zone setting up over our area between all rain,
sleet/freezing rain, and snow. The track and timing of the
surface low will make all the difference, and hopefully that
will come into focus over the next few forecast cycles. The
trend as of late has been a bit slower and further south with
the track of the surface low, which would actually result in
more impacts for our region. The potential is certainly there
for accumulating snow, possibly significant, for areas north of
Philadelphia. A wide variety of outcomes exist still among
deterministic guidance, with the GFS bringing significant
accumulations from Philadelphia on north, the GEM having minor
snowfall limited to northern areas, and the ECWMF and its AI
counterpart going more in the middle of those solutions. NBM
Probability of 2" or more of snow is around 50-80% from Philly
on north with probabilities decreasing drastically the further
south you go. Probability of 6" or more of snow is around 15-30%
for the Philly metro, Lehigh Valley, and Poconos, with around a
40-50% chance for North Jersey.

Another component with this storm is the potential for some freezing
rain and measurable ice accumulation. Again, still too early to know
for sure given low confidence, but current probabilistic
guidance from the NBM has around a 30-50% chance of ice
accumulations greater than a tenth of an inch from the I-95
corridor on west.

Overall, as mentioned previously, this is a low confidence forecast,
but areas from about Philadelphia on north and west should keep
a close eye on the forecast as this storm could be potentially
disruptive and bring large impacts.

Saturday looks to be a period in between systems, however, some
lingering rain or snow showers could hover over the region as an
area of low pressure meanders offshore. Some guidance even shows a
small chance for freezing rain/drizzle. However, things could also
be completely dry if the low offshore goes further out to sea. PoPs
are only around 20-30% for Saturday.

For Saturday Night, a warm front lifts northward with a stronger
cold front coming through sometime Sunday or Sunday Night. Some cold
air especially on Saturday Night and early Sunday could get trapped
over the Lehigh Valley and Poconos if the warm front is slower and
gets hung up. Some guidance shows another period of freezing rain
possible. For most though, it will primarily be an all rain event
with the cold front coming through on Sunday Night/Monday morning.

Temperatures likely take a tumble next week with breezy conditions
in a cold advection pattern, though it should be dry as we get
towards the new year.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Rest of Today...Prevailing MVFR ceilings and occasional MVFR
visibility restrictions due to drizzle/mist. At times terminals
will go VFR as pockets of precipitation move out or ceilings
scatter out. Precipitation ends between 18Z and 21Z. South to
southwest winds around 5-10 kts. Moderate confidence.

Tonight...Any lingering MVFR ceilings lift and scatter out to
VFR by around 03Z. Westerly winds increasing to 10-15 kts and
shifting northwest by 06Z with gusts 20-25 kts. High confidence.

Wednesday...VFR. A gusty NW wind with gusts upwards of 25-30
knots. Winds start to decrease around 21Z to 5-10 knots. High
confidence.

Outlook...

Wednesday Night...VFR. No significant weather.

Thursday...MVFR/IFR conditions possible, especially from KPHL on
south as low clouds and showers move through.

Thursday Night...VFR. No significant weather.

Friday through Saturday...Sub-VFR conditions expected at all
terminals is a winter storm impacts the region. All precipitation
types on the table for all terminals, though the highest chance for
snow and freezing rain will be from the I-95 corridor on west.

Saturday Night through Sunday...Sub-VFR conditions expected.
Primarily rain at all terminals, though KABE/KRDG could see some
freezing rain on Saturday Night.

&&

.MARINE...
After marginal Small Craft Advisory conditions today across the
Atlantic coastal waters due to southerly wind gusts around
20-25 kts and seas near 3-5 feet. There will be a lull for a few
hours this evening as conditions fall below Small Craft Advisory
criteria. After midnight, winds and seas will increase as
another period of Small Craft Advisory conditions develop. Northwest
winds gusting 25- 30 kts are forecast by dawn Wednesday with
seas 3-5 feet. The Delaware Bay has a Small Craft Advisory that
runs from 4 AM to 4 PM on Wednesday. There is the potential for
occasional gale force gusts on the Atlantic coastal waters but
due to the period being brief, no Gale Warning was issued.

Outlook...

Wednesday Night...No marine headlines expected.

Thursday through Thursday Night...SCA conditions possible (50%) as
winds near 25 kt out of the northwest and seas near 5 feet.

Friday...No marine headlines expected.

Friday Night through Saturday...SCA conditions possible (50%) with
seas nearing 5 feet.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Wind Advisory from 1 AM to 1 PM EST Wednesday for PAZ054-055.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory from 4 AM to 4 PM EST Wednesday for
     ANZ430-431.
     Small Craft Advisory until 6 PM EST Wednesday for ANZ450>455.

&&

$$

SYNOPSIS...Guzzo/Hoeflich
NEAR TERM...Guzzo/Staarmann
SHORT TERM...Hoeflich
LONG TERM...Hoeflich
AVIATION...Guzzo/Hoeflich
MARINE...Guzzo/Hoeflich