497
FXUS61 KPHI 170531
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
1231 AM EST Mon Nov 17 2025

.SYNOPSIS...
Strong low pressure moves into the Canadian Maritimes tonight
and into Monday. High pressure slides by to our south later
Tuesday, then weak low pressure tracks eastward from the Ohio
Valley to the Mid-Atlantic Tuesday into Wednesday. A warm front
lifts north across our region Thursday night and Friday,
followed by a weak cold front Friday night. A secondary cold
front may move through Saturday night.

&&

.NEAR TERM /THROUGH TONIGHT/...
The last waves of some light rain and/or non-accumulating snow
showers, mostly sprinkles and/or flurries, will taper off during
the early morning hours. If there is any measurable
precipitation, it will only be a couple of hundredths of an inch
or so. For the overwhelming majority of the region, it will
only be a trace.

The region will continue to find itself between an upper trough
over the Northeast and high pressure building into the Great
Lakes and Ohio and Tennessee Valleys. Strong shortwave energy
will dive into the base of the trough early this morning and
into this afternoon. The sprinkles and/or flurries will taper
off late this morning, and the shortwaves will generally result
in partly to mostly cloudy skies later today.

The main issue will once again be the strong winds, though not
nearly as strong as they were on Sunday. West to northwest winds
will diminish to 10 to 15 mph with gust up to 20 mph early this
morning, then winds will quickly ramp up to 15 to 25 mph with
gusts up to 35 mph starting late this morning. Winds diminish
after sunset with loss of daytime heating, and winds become 5 to
10 mph tonight.

A seasonably chilly day on tap with temperatures almost 10
degrees below normal for this time of the year with highs in the
mid to upper 40s. Lows tonight will be in the upper 20s to
around 30, though warmer along the coasts. With skies clearing
out tonight, if winds can drop to less than 5 mph, especially in
outlying areas, radiational cooling may result in locally
colder temperatures.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
Cold air continues to filter in Monday night through Tuesday night.
This is with a mainly west to west-northwest wind as we are in the
cyclonic flow of a low pressure system well to the north near the
Canadian Maritimes. There will be a high pressure system building
into the region which also leads to a tighter pressure gradient that
relaxes more through the day Tuesday and into Tuesday night. In
terms of temperature, lows are in the mid 20s to low 30s Monday
night and upper 20s to upper 30s Tuesday night. Our highs on Tuesday
are in the low 40s to low 50s and mid 40s to mid 50s Wednesday. For
winds, gusts upward of 20-30 mph Monday night trend lower into
Tuesday with gusts 15-25 mph as the pressure gradient lessens.

We do not see too much in the form of cloud cover Monday night with
more clouds filtering in throughout the day Tuesday. Precip looks
pretty minimal Monday night into the first half of Tuesday. The only
exception would be any lingering snow showers due to the lake effect
upstream. However, this looks limited at this time with the best
potential being in the Poconos. Due to the limited potential, PoPs
were kept below mentionable.

By Tuesday afternoon into Tuesday night, we see a low pressure
system that starts to enter the region from the west. This low
pressure system looks to be on the weaker side. Given the expected
track being more southerly, the best potential for any rain is in
Delmarva, parts of southeast Pennsylvania, and southern New Jersey.
As you get closer to I-78 and north, the potential for precip
lessens to 20-40%. There is less confidence on precip making it as
far as I-80 or even north of this area where PoPs are 20-30%. One
key note is that if precip does make it that far north, some light
snow or a rain/snow mix can be expected at times Tuesday night,
especially for the Poconos and Sussex county New Jersey. Any precip
does look to end on Wednesday morning and we trend drier through the
day with a partly to mostly cloudy sky.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
In the long term period, we do have more opportunities for
precipitation and temperatures moderate. There is the potential for
an isolated shower Wednesday night into Thursday with a piece of
upper-level energy moving through. Overall, not much precipitation
expected for that timeframe but we do stay mainly mostly cloudy.
Highs on Thursday are in the mid 40s to upper 50s. By Thursday
night, a warm front lifts northward leading to some showers being
possible Thursday night into Friday morning. The better potential
for any rain associated with this system looks to be ahead of the
cold front during the day Friday into Friday night. The cold front
will pass through the area overnight Friday. Due to the warm front
Thursday night, we do trend warmer Friday with highs in the mid 50s
to mid 60s.

The unsettled weather continues into Saturday with another potential
for rain during the day Saturday into Saturday night. This is with a
secondary cold front. Overall details are less certain with this
cold front due to timing, track, and intensity of the low pressure
system that this front is attached to. Right now, PoPs are at slight
chance to chance for this time period. Highs on Saturday are in the
mid 50s to mid 60s.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Early this morning (through 12Z)...VFR. Some light SHRA/SHSN are
possible until 09Z, but conditions will remain VFR. W-NW winds
10 to 15 mph with gusts up to 20 kt. Moderate confidence
overall.

Today...VFR. BKN CIGs 050-080. W-NW winds 15 to 20 kt with 35 to
35 kt gusts, diminishing after 21Z. High confidence.

Tonight...VFR. W-NW winds 5 to 10 kt. High confidence.

Outlook...

Tuesday...Areas of sub-VFR conditions possible at night due to some
rain, especially south of KPHL.

Wednesday and Thursday...Mainly VFR.

Friday...Sub-VFR conditions possible with rain moving through
the area Friday and Friday night.

&&

.MARINE...
A tight pressure gradient over the waters will result in gale
force winds continuing through this afternoon, though there may
be a lull in the gales early this morning before ramping up
again shortly after sunrise. W-NW winds 15 to 25 kt with gusts
up to 35 kt. Winds diminish to Small Craft Advisory criteria
this evening, then SCAs may be needed, at least on the ocean
waters, tonight.

Outlook...

Tuesday through Thursday...The conditions are anticipated to be
below Small Craft Advisory criteria.

Friday...Small Craft Advisory conditions possible Friday and
Friday night with an increasing SW wind to near 25 knots and
seas building to near 5 feet.

&&

.FIRE WEATHER...
Today, west to northwest winds will increase to 15 to 20 mph
with 30 to 35 mph gusts with MinRH values generally 35 to 40
percent, though possibly as low as 30 to 35 percent across the
eastern shores of Maryland and Delaware. Since RH Values will be
lower in Delmarva, and there was less in the way of rainfall
there this weekend, there is the potential for fire weather
concerns in those areas.

Will coordinate and collaborate with Fire Weather Partners to
see if any statements are needed across the southern half of the
forecast area.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Gale Warning until 6 PM EST this evening for ANZ430-431-
     450>455.

&&

$$

SYNOPSIS...Gorse/Guzzo
NEAR TERM...MPS
SHORT TERM...Guzzo
LONG TERM...Guzzo
AVIATION...Gorse/MPS
MARINE...Gorse/MPS
FIRE WEATHER...MPS